Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3850793 A
Publication typeGrant
Publication dateNov 26, 1974
Filing dateMar 23, 1973
Priority dateMar 23, 1973
Publication numberUS 3850793 A, US 3850793A, US-A-3850793, US3850793 A, US3850793A
InventorsHornbostel L, Knutsen C
Original AssigneeCenter For Management Services
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Molding machine for producing uniform pulp products
US 3850793 A
Abstract
A machine for molding an article such as a dash panel from a pulp slurry includes a frame which supports a movable stock pan containing the slurry from which the article is molded. A perforate mold for forming the article is carried in a plenum mounted adjacent the end of a hollow arm. A passage through the arm communicates between a remote vacuum source and the interior of the plenum, and a valve in the passage may be opened and closed to control the application of the vacuum to the mold. In use, the stock pan is lifted from its position beneath the mold to immerse the latter in the slurry and the valve is opened so the slurry is sucked through the mold, the pulp fibers in the slurry collecting on the outer face of the mold. A bleed port in the passage permits outside air to be drawn into the passage to cushion the application of the vacuum on the mold so the pulp fibers are collected over a relatively extended period of time to keep the density of the article uniform throughout its thickness. Ported plates in the stock pan streamline the flow of slurry into the stock pan from a main supply to keep the pulp fibers uniformly distributed throughout the slurry in the stock pan.
Images(9)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent [191 H0rnb0stel et al.

[451 Nov. 26, 1974 MOLDING MACHINE FOR PRODUCING UNIFORM PULP PRODUCTS [75] Inventors: Lloyd H. HornbosteliClarence R.

Knutsen, both of Beloit, Wis.

[73] Assignee: Center For Management Services And Applied Research, Inc., Beloit, Wis.

[22] Filed: Mar. 23, 1973 [21] Appl. No.: 344,276

[52] U.S. Cl 162/391, 162/228, 162/393, 162/410, 162/411 [51] Int. Cl. D2lj 3/00 [58] Field of Search 162/387, 388, 391, 393, 162/390, 410, 411, 385, 220, 228

[56] References Cited UNITED STATES PATENTS 2,234,979 3/1941 Randall et al 162/385 X 2,663,230 12/1953 Wagner 162/410 2,990,314 6/1961 Leitzel 162/220 3,016,091 l/l962 Daniele 162/391 3,066,069 11/1962 Ednell 162/228 X 3,507,746 4/1970 Rhine 162/363 3,567,575 3/1971 Emery.... 162/391 X 3,594,273 7/1971 Williams 162/228 X Primary Examiner-Robert L. Lindsay, Jr. Assistant Examiner-Alfred DAndrea, Jr. Attorney, Agent, or Firm-Wolfe, Hubbard, Leydig, Voit & Osann, Ltd.

[ ABSTRACT A machine for molding an article such as a dash panel from a pulp slurry includes a frame which supports a movable stock pan containing the slurry from which the article is molded. A perforate mold for forming the article is carried in a plenum mounted adjacent the end of a hollow arm. A passage through the arm communicates between a remote vacuum source and the interior of the plenum, and a valve in the passage may be opened and closed to control the application of the vacuum to the mold. In use, the stock pan is lifted from its position beneath the mold to immerse the latter in the slurry and the valve is opened so the slurry is sucked through the mold, the pulpfibers in the slurry collecting on the outer face of the mold. A bleed port in the passage permits outside air to be drawn into the passage to cushion the application of the vacuum on the mold so the pulp fibers are collected over a relatively extended period of time to keep the density of the article uniform throughout its thickness. Ported plates in the stock pan streamline the flow of slurry into the stock pan from a main supply to keep the pulp fibers uniformly distributed throughout the slurry in the stock. pan.

After the article has been molded a sprayer is advanced between the plenum and the stock pan to spray low pressure water against the edges of the mold and thereby wash away pulp fiber drippings. Thereafter, the sprayer is retracted and the arm is swung through an arc to carry the mold into a position below a press which is lowered and clamped to the plenum. A bladder carried by the press then is inflated to squeeze excess water from the article and, by virtue of the shape of the plenum and the arm, the water flows out of the plenum and through the arm for re-processing and re-use. Once the excess water is squeezed from the article, the plenum is indexed into an inverted position and the article is blown off the mold and onto a conveyor by forcing pressurized air into the plenum. The arm and plenum then are moved back to their original positions above the stock pan, and the sprayer is advanced between the mold and the stock pan to spray high pressure water back and forth across the outer face of the mold to wash away any pulp fibers clinging to the mold prior to immersing the mold in the stock pan to begin the nextcycle. In an alternative embodiment, a similar machine includes two plenums mounted on arms extending in opposite directions from each other and each plenum carries a mold so the capacity of the second machine is double that of the first machine.

31 Claims, 20 Drawing Figures PATENIEMISVZBIQM vSHEET EM 9 aa amrn- Il i- I L? k 1W MIN MUM 1 I PATENTED NEW 2 5 I974 SHEET 3 OF 9 MOLDING MACHINE FOR PRODUCING UNIFORM PULP PRODUCTS BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION One primary object of the present invention is to provide a new and improved molding machine of the foregoing character which is adapted to form the article in a novel manner so that the article is formed of a predetermined thickness and with a uniform density throughout its thickness to keep from forming either an excessively weak or an excessively strong article. A more detailed object is to accomplish the foregoing through the use of novel means for maintaining an even distribution of the pulp in the slurry and further through the provision ofunique means for increasing the length of time over which the vacuum builds up to draw the slurry through the mold so that the pulp fibers build up uniformly throughout the thickness of the article without becoming gradated by size.

A further object is to provide the machine to operate in a novel manner to form said articles by swinging the mold between successive forming and pressing stations and indexing the mold on its swingable support between its pressing and ejecting positions so as to orient the mold for ejection of the article from the mold.

Another object is to provide a unique arrangement for draining water from the machine during the forming and pressing operations to avoid possibly rewetting the article after the excess water is squeezed from the article.

A more detailed object of the present invention is to provide'a unique siphon arrangement for removing the strained slurry or white water from behind the mold as the slurry is drawn throughthe mold during the molding process.

Another more detailed object is to provide a unique plenum which supports the mold and defines a pressure chamber around the back side of the mold, the'plenum being of a unique shape to drain water away from the mold during the pressing operation so as to avoid rewettingof the molded article once the excess water is removed from the article.

The invention also resides in the provision of a novel' stock pan containing the slurry in which the mold is immersed to a predetermined level and in the unique construction for moving the mold away from the stock pan to a position beneath a press for squeezing excess water from the article. In addition, the invention resides in the unique manner in which the excess water is squeezed from the article and drained out of the plenum.

The invention is characterized further by the provision of a unique sprayer movable between the plenum and the stock pan and adapted both to wash away pulp fiber drippings from the edge of the mold and the article after the molding operation and prior to the pressing operation and to cleanse the mold of pulp fibers adhering to the outer face thereof after ejection of the article from the mold.

These and other objects and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a fragmentary front elevational view of a molding machine embodying the novel features of the present invention.

FIG. 2 is a fragmentary cross-section taken substantially along line 2-2 of FIG. I and having phantom lines which show partsv of the machine moved positions.

FIG. 3 is an enlarged fragmentary cross-section taken substantially along line 3-3 of FIG. 1.

FIG. 3a is an enlarged fragmentary cross-sectional view taken through the mold.

FIG. 4 is an enlarged fragmentary view taken substantially along line 4-4 of FIG. 1.

FIG. 5 is reduced fragmentary cross-section taken substantially alone line 55 of FIG. 3.

FIG. 5a is an enlarged fragmentary view showing parts of the machine in cross section.

FIG. 6 is a fragmentarycross-section similar to FIG. 2 but showing parts of the machine in moved positions.

FIG. 7 is an enlarged fragmentary cross-sectional view taken substantially along line 7-7 of FIG. 6.

FIG. 8 is a fragmentary cross-section taken substantially along line 8-8 of FIG. 7.

FIG. 9 is a fragmentary cross-section similar to FIG. 6 but showing parts of the machine in moved positions.

FIG. 10 is a fragmentaryfront elevational view similar to FIG. I but showing parts of the machine in moved positions. i

FIG. 11 is an enlarged fragmentary cross-section taken substantially along line 11-11 of FIG. 10.

FIG. 12 is a fragmentary view taken substantially along line 12 -12 of FIG. 10.

FIG. 13 is a fragmentary side elevational view of another embodiment of a molding machine incorporating the novel features of the present invention.

FIG. 14 is a fragmentary cross-sectional view taken substantially along line I4-l4 of FIG. 13.

FIG. 15 is an enlarged fragmentary cross-sectional view taken substantially along line 15-15 of FIG. 14.

FIG. 16 is a fragmentary side elevational view similar to FIG. 13 but showing parts of the machine in moved positions.

FIG. 17 is a fragmentary cross-sectional view taken substantially along line 17--17 of FIG. 16.

FIG. 18 is an enlarged fragmentary cross-sectional view taken substantially along line 18-18 of FIG. 17.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in the drawings for purposes of illustration, the present invention is embodied in a molding machine 20 particularly suitable for use in molding an article 21 (see FIG. 3) from a pulp slurry 23. It will be appreciated that while the present invention is illustrated and described for molding a dashboard 21 adapted to collapse upon impact to protect an occupant of an automobile against serious injury, other types of articles also may be molded with this type of machine.

Herein, a perforate mold 24 is used to strain the pulp fibers from the slurry, the fibers collecting on the outer face of the mold in the desired shape. While different types of molds may be employed, the mold in the present instance includes a wire screen 22 (see FIG. 3a) which may be formed from 40 to 60 mesh screen depending upon the desired characteristics of the article to be molded. To support the screen in its desired shape, it is backed by a relatively rigid casting 28 which is formed of aluminum and is perforated with /8 inch diameter holes drilled on /8 to /2 inch centers.

The slurry is formed in a conventional manner from waste corrugated paper clippings stirred in water so as to separate into fibers about three-fourths inch long. The fibers comprise about one percent of the slurry and flock together to give the slurry a lump appearance. Also added to the slurry are a wet strength resin and a thermo-setting plastic resin (e.g., phenolic resin), both of which adhere to the fibers and thus are separated from the water with the fibers during the forming process. The thermo-setting resin melts upon subjecting the freshly molded dashboard to heat and, when cooled, the resin hardens to bind the fibers together and rigidify the dashboard.

Initially, the dashboard 21 is formed by immersing the mold 24 in the slurry 23 and utilizing a vacuum pump 32 to draw the slurry into and through the mold. As shown in FIG. 1, slurry from a remote main supply 42 is collected in a stock pan 26 through a lower inlet 27 (FIG. 2) communicating with the supply through a pipe '29. The stock pan is mounted on a frame 30 which also supports an arm 31 for carrying the mold above the stock pan. More particularly, the mold is mounted on a plenum 33 which in turn is mounted adjacent one end 34 of the arm. A vacuum passage 35 communicates between the vacuum pump and the mold, the passage extending through the arm and into the interior of the plenum.

To immerse the mold 24 in the slurry 23 collected in the stock pan 26, the latter is lifted on the frame 30 from a retracted lower position (see FIG. 1) to an advanced upper position (FIG. 3) by two fluid-actuated cylinders 36 connected to opposite ends 37 of the pan by brackets 38 and supporting the pan on the frame. Once the mold is immersed in the slurry, a main vacuum valve 39 in the passage 35 is opened so the pump evacuates the plenum 33 and causes slurry to be sucked through the mold, the fibers in the slurry collecting on the outer face 25 of the mold to form the dashboard 21. The strained slurry or white water then flows through the passage 35 toward the pump 32 and into a separator tank 48. The white water enters the separator tank through an upper inlet 48a and is collected temporarily in the lower portion of the tank. The passage 35 communicates with the pump through an air outlet 48b in the top of the tank so that only the air is drawn to the pump. Periodically, the white water is drawn from the tank through a lower outlet 48c and is collected for reprocessing and recycling.

After the dashboard 21 initially is formed on the mold 24, the stock pan 26 is lowered and the mold is carried by the arm 31 to a press 40 (see FIG. 2)

adapted to squeeze excess water from the dashboard while also compressing the latter to its desired final thickness. Thereafter, the dashboard is ejected from the mold onto a conveyor 41 and is carried away from the machine 20 to be dried in an oven (not shown) and hot-pressed to set the plastic resin and thereby complete the molding process. a

When forming an article 21 in the foregoing manner, it is desirable to control the thickness of the article as the fibers are picked up on the mold 24 so as to keep the fibers from breaking during subsequent pressing and thereby avoid forming cracks in the article. Also, it is desirable to keep the density of the article relatively uniform throughout the thickness of the article and thereby distribute the resin evenly throughout the article so that, during further processing, both the inside and outside portions of the article will be of equal strength. These features are desirable particularly when molding articles such as the impact-crushable dashboards 21 in order to keep each dashboard from being so weak as to collapse too easily when impacted or so strong as to be likely to cause injury when impacted by the occupant of an automobile during a crash.

In accordance with the primary aspect of the present invention, the molding machine 20 includes unique means for controlling the manner in which the pulp fibers are collected on the mold 24 so the article 21 may be formed of a predetermined thickness and of a relatively uniform density throughout such thickness. This is accomplished through the novel provision of a bleed port 43 (FIG. 5) within the passage 35 to permit the vacuum pump 32 to draw outside air into the passage so that the vacuum applied to the mold increases gradually to a preselected intensity without causing the larger and smaller pulp fibers to become gradated by size as they collect on the mold to the predetermined thickness dictated by the preselected intensity of the vacuum. Also, by virtue of the novel construction of the stock pan 26, the pulp fibers are distributed evenly throughout the slurry 23 in the stock pan so as to collect evenly across the outer surface 25 of the mold. For this latter purpose, means including a plurality of ported plates 44 (FIGS. 3 and 4) are disposed within the stock pan adjacent the inlet 27 and streamline the flow of slurry into the stock pan so that the pulp fibers remain uniformly distributed throughout the slurry in the stock pan. Thus, by keeping the pulp fibers distributed evenly throughout the slurry and by gradually increasing the vacuum to the preselected intensity so the larger and smaller fibers collect together on the mold without becoming gradated, the article is formed on the mold to a predetermined thickness and the density of the article is relatively uniform throughout such thickness.

In the present instance, the plenum 33 is supported between two arms 31, each of which is secured at one end 45 (FIG. 3) to a substantially horizontal tubular support 46 and is spaced from the other arm. Herein, each of the arms is hollow so that it defines one branch 47 (FIGS. 3 and 5) of the passage 35, the latter communicating with the interior of the plenum through openings 49 in opposite sides 50 of the plenum. Corresponding holes 51 in the arms are aligned with the openings in the plenum and relatively thick sealing rings 53 bolted to the plenum around the openings engage the arms around the aligned holes to keep the vacuum from leaking between the arms and the plenum.

As shown in FIG. 3, the interior of the plenum is divided into two chambers 54 by a partition 55 extending the full length of the interior of the plenum, and the chambers each communicate with the passage 35 through the openings 49. Herein, there are four of the openings in the plenum, one opening at each end of each chamber so that there are two openings in each of the two opposite sides of the plenum. One mold 24 is mounted in each of the chambers, the two molds each being bolted to a lower wall 56 of the plenum and extending parallel with each other within two elongated rectangular openings 57 (FIG. 3) in the lower wall. It will. be appreciated that while two molds are disclosed in the exemplary embodiment for molding the dashboards 21, virtually any number of molds may be secured to the plenum for molding articles such as the dashboards.

To control the manner in which the pulp fibers are collected on the outer faces 25 of the molds 24, two of the bleed ports 43 (FIGS. 1 and 3) are formed in the arms 31 although, if desired, the ports may be formed in the plenum and open directly into the chambers 54. Preferably, however, one bleed port is located adjacent the free end 34 of each arm and communicates with the branch 47 of the passage 35 in that arm. The bleed ports are opened and closed by valves a controlled by solenoids 60 (FIG. 5a), the valves being open when vacuum is applied to the molds so as to permit outside air to be drawn through the ports and into the passage by the vacuum as the dashboards are being molded. This arrangement, in effect, cushions the application of the vacuum so that the larger and smaller pulp fibers collect on the outer face of the mold over a relatively extended period of time and without being gradated by size so as to keep the density of the dashboards relatively uniform throughout their thicknesses and 'to cause the inside and outside portions of the dashboards to be of generally the same strength.

One of the porting arrangements is shown in more detail in FIG. 5a and includes an upwardly projecting neck 43a integrally formed in the'arm around the port 43. Connected to the neck is a housing 43b within which is mounted the solenoid 60 and the valve 60a, the latter normally closing a lower aperture 43c in the housing under the urging of a spring 60b. Advantageously, a removable cap 62 having a central opening 62a is threaded onto the upper end of the housing and provides a restriction for the air entering the housing so as to control the amount of air that can be drawn into the passage 35 through the port 43. It will be appreciated that by using caps having different sizes of central openings, the amount of air entering the passage 35 during molding may be changed to adjust the length of time it takes for the vacuum to build up to its preselected intensity. In this way, the machine 20 may be adjusted to mold articles with different densities and thicknesses.

Further control of the formation of the dashboards 21 is provided by a vacuum regulator valve 61 (FIG. 1) which is adjustable selectively to control the ultimate intensity of the vacuum being applied to the molds 24. The regulator valve is located within a pipe 63 between the ports 43 and the separator tank 48. The pipe is connected to the tubular support 46 by a rotatable joint 68, defines a portion of the passage 35 and houses the main vacuum valve. The regulator valve is mounted between themain valve and the joint and provides a relatively fine control to regulate the intensity of the vacuum applied to the molds. The intensity of the vacuum, together with the rate control provided by the bleed ports 43, determines the thicknesses to which the pulp fibers build up on the outer faces 25 ofthe molds. This is because for each vacuum intensity, the fibers collect on the molds until the loss of pressure through the collected fibers equals the difference between the vacuum pressure in the plenum chambers 54 and the natural pressure in the slurry adjacent the outer surfaces of the newly molded dashboards. Therefore, when the bleed ports are fitted with caps 62 having one size of opening 62a, the'thicknesses of the dashboards being formed may be increased by increasing the intensity of the vacuum so. more fibers collect on the: molds, or the thicknesses of the dashboards may be decreased by decreasing the intensity of the vacuum.

To avoid the need of adjusting the regulator valve 61 for each molding operation, the molds 24 are immersed to and held at a predetermined depth in the slurry in the stock pan 26 for each consecutive operation so that the natural pressure in the slurry 23 adjacent the molds will be virtually the same for each immersion. For this purpose, the stock pan includes an outer tank 64 (FIG. 3) and an immersion tank 65 having side walls 66 spaced inwardly of the side walls 67 of the outer tank andofa height less than the height of the side walls 67 so the upper edges 69 of the side walls 66 serve as weirs to maintain a constant level of slurry within the stock pan. When the molding machine 20 is in use, the amount of sluurry flowing from the main supply 42 exc eeds the amount required for molding the dashboards 21, and a portion of the excess slurry flows over the weirs into a return passage 70 defined by the space between the sidewalls 66 and 67 of the two tanks. The return passage communicates with a lower outlet 71 (FIG. 4) in the outer tank, and the excess slurry flows through the return passage and the outlet in a return pipe 73 communicating with the main supplyto return the excess slurry to the main supply Accordingly, when the-cylinders 36 are actuated to lift'the stock pan 26. a predetermined distance, the molds are immersed in the slurry 23 contained in the. immersion tank 65 to a predetermined depth regardless of the amount of slurry displaced by the molds 24 and the amount of slurry sucked through the molds by the vacuum.

To control the flow of slurry 23 into the immersion tank 65 so the pulp fibers remain evenly distributed throughout the slurry, the immersion tank includes an inlet chamber 74 (see FIG. 3) and an upper chamber 75. The ported plates 44, there herein being four such plates, are disposed between the two chambers and have spaced apertures 72 to streamline the flow of the slurry from the inlet chamber upwardly into the upper chamber within which the molds are immersed. The inlet chamber is defined by spaced end walls 76 and 77 (FIG. 5), and the inlet 27 for the stock pan 26 is formed in the end wall 76 above the outlet 71. An outlet 79 is formed in the opposite end wall 77 and opens into a pipe 80 which leads to the main supply 42 of slurry to return a portion of the slurry entering the inlet chamber to the main supply. In the top of the inlet chamber is an opening 81 (see FIG. 4) within which the four plates 44 are mounted. Each of the plates is bolted to an angle iron 83 extending around the opening for easy removal and replacement with different plates with different sizes of apertures so as to provide a means for controlling the rate at which the slurry flows into the upper chamber. By virtue of the ported plates, the flow of slurry into the immersion chamber is streamlined to avoid the formation of areas in the chamber where pulp fibers may concentrate either to a greater or lesser degree and possibly cause the formation of excessively thick or thin spots in the dashboards being molded.

As shown in FIG. 5, a wall 84 defining the bottom of the inlet chamber 74 is spaced upwardly of a bottom wall 85 of the outer tank 64 and slants upwardly upon progressing from the inlet 27 toward the outlet 79 of the inlet chamber. Accordingly. the cross-sectional area of the inlet chamber becomes progressively smaller toward the outlet and this advantageously keeps the pressure of the slurry in the inlet chamber relatively even across all of the plates 44 so that approximately the same amount of slurry flows upwardly through each ofthe four plates into the upper chamber 75.

To avoid an accumulation of white water within the plenum 33 as slurry from the immersion chamber 75 is sucked through the molds 24 by the-vacuum. the white water is siphoned out of the, plenum and into the two branches 47 of the passage 35 to be sucked by the vac uum through the tubular support pipe 46 and into the separator tank 48. This is accomplished with four siphon tubes 86 (FIGS. 3 and and by taking advantage of the outside air which is drawn into the two branches of the passage through the bleed ports 43 to suck the white water from adjacent the bottom wall 56 of the plenum and into the two branches of the passage. Two of the siphon tubes are located within each of the chambers 54, the tubes being disposed at opposite ends of the chambers and extending upwardly from open lower ends 87 adjacent the bottom wall to open upper ends 89 extending into the openings 49 in the sides 50 of the plenum. The outside air flows across the open upper ends of the siphon tubes thereby creating a pressure differential between the upper and lower ends of the tubes so the white water is sucked up through the tubes and into the passage branches. Thus, the plenum is emptied of white water as an incident to the molding operation, and the white water is collected for reprocessing and recycling.

Once the dashboards 21 are formed on the molds 24 in the manner described, the stock pan 26 is lowered to its retracted position by the cylinders 26, and a sprayer 90 (FIGS. 1 and is advanced between the molds and the stock pan to wash away any excess pulp and pulp fiber drippings adhering to the edges of the molds and the newly formed dashboards. As shown in FIG. 1, the sprayer normally rests on support members 91 which are secured to the frame 30 adjacent one end 37 of the stock pan and includes a shower tray 93 supported by wheels 94 on tracks 95 extending along the tops of the support members. Additional tracks 96 extend along the upper edges of the front and rear walls 67 of the outer tank 64 of the stock pan and are aligned with the tracks on the support members to permit the shower tray to be rolled into position beneath the plenum 33. The shower tray is generally rectangular in shape and encompasses an area somewhat larger than the area defined by the lower wall 56 of the plenum. The tray includes opposite end walls 97 and 98, side walls 99 (FIG. 11) and a bottom wall 100. A toothed rack 101 is secured to the outside surface of the rearward side wall of the tray along the upper edge thereof and engages a gear 103 fixed on a rotatable shaft 104 projecting forwardly from a small motor 105 (FIG. 10) mounted on the frame 30 adjacent the rearward side wall. With this arrangement, the tray may be advanced beneath the plenum by actuating the motor to rotate the shaft in a counterclockwise direction (FIG. 10).

To wash away the pulp fiber drippings from the edges of the molds 24, four spaced pipes 106 are mounted within the shower tray 93 and extend parallel with each other, the opposite ends 107 of the pipes being supported by the end wall 98 of the tray and a header 92 attached to the wall 97. A low pressure water source (not shown) communicates through a small hose 109 which connects to one end of the header and, as water from the source is forced through the header and into the pipes, small openings 110 along the tops of the pipes direct the water upwardly to wash the pulp fiber drippings off the edges of the molds. Advantageously, the water sprayed from the pipes falls back into the tray and thus is kept from diluting the slurry 23 in the stock pan 26. As shown in FIG. 10, the bottom wall 100 of the tray is slanted downwardly from the end wall 98 toward the other end Wall 97 so that the water flows out of the tray through a drain 111 located adjacent the latter wall and is collected for reprocessing and recirculatIOn.

After the drippings are cleaned from the edges of the molds 24, the tubular support 46 is rotated on the frame 30 to move the arms 31 through a predetermined arc (herein, about 180) to carry the molds away from the stock pan 26 and into predetermined positions beneath the press 40 (see FIG. 2). Attached to the support opposite the arms is a generally cylindrical counterweight 113 adapted to offset the weight of the plenum 33 and the molds. Prior to rotating the arms to carry the molds to the press, the sprayer 90 is retracted from between the molds and the stock pan and into its normal rest position on the support members 91 so as to be out of the way of the counterweight. When positioned beneath the press, the molds are oriented so their outer faces 25 are directed upwardly toward the press (see FIG. 6) as is the wall 56 of the plenum which, in this position, is located essentially in a horizontal plane.

To move the molds 24 and the plenum 33 into position beneath the press 40, the tubular support 46 is se cured to two spaced A-shaped members 114 (FIGS. 1 and 2) by two collars 115 and 116 journaled within the upper ends of the members. The collars 115 opposite a closed end 112 of the support 46 includes a large gear 117 fixed to the support adjacent the rotatable joint 68, and a hydraulic motor 119 is supported on the frame 30 by a platform 120 located beneath the gear. The motor is drivingly connected to the gear by way of a rotatable shaft 121 and a small gear 123 which 'is mounted on the shaft to turn the large gear and thereby rotate the arms 31 to carry the molds toward the press.

Once the molds 24 are located in their predetermined positions beneath the press 40, the latter is advanced toward the molds from an upper out-of-the-way position into a lower position to engage the upwardly facing wall 56 of the plenum 33 and to compress the dashboards 21 to their desired thicknesses while, at the same time, squeezing excess water from the dashboards through the molds and into the two chambers 54 within the plenum. Herein, the press includes a generally rectangular head 124 (FIG. 7) which is approximately the same size and shape as the lower wall of the plenum. The head is connected on the lower end of a fluidoperated actuator 125 (FIG. 2) secured to the frame 30, the actuator comprising an elongated rod 126 which projects downwardly from a cylinder 127 and which is bolted to the center portion of the head. Preferably, two inflatable bladders 129 (FIG. 7) are sealed to the underside of the head, each of the bladders being positioned on the head to compress the dashboard in one of the molds when the head is clamped to the wall 56 of the plenum 33. Two air lines 130 leading from the head above each of the bladders provide air from a high pressure source (not shown) for inflation of the bladders.

Holding the press head 124 and the plenum 33 together as the bladders 129 are inflated are six clamps 131 (see F168. 1 and 2), three each being mounted on the press head along opposite sides thereof to lock against front and rear walls 133 and 134 of the plenum. As shown in FIG. 6, each of the clamps is operated by a fluidactuated cylinder 135 mounted on top of the press head and having a rod 136 projecting beyond the edge of the head. An eye 137 on the end of each rod is pinned to the upper end of a downwardly extending lever 139 which is mounted by a pivot 140 on the side of the press head intermediate the ends of the lever. The lower ends of the levers are hooked inwardly to fit within notches 141 (FIG. 1) located in the front and rear walls 133 and 134 of the plenum to lock the plenum together with the press head as the rods are advanced from their cylinders.

Once the press head 124 and plenum 33 are locked together, the bladders 129 are inflated to compress the dashboards 21 on the molds 24 while also squeezing excess water through the molds and into thechambers 54.

In accordance with another novel aspect of the present invention, the plenum 33 and the arms 31 each are shaped in a novel manner to drain the excess water away from the molds to avoid rewetting the articles 21 (e.g., the dashboards)-after they are squeezed by the press to remove the excess water. For this purpose, the plenum and the arms are each constructed, as shown in FIG. 2, so that walls 142 and 143 of the plenum and the arms, respectively, slope downwardly toward the tubular support 46 once the arms are swung through the predetermined are from above the stock pan 26 to carry the plenum to its predetermined position (shown in phantom) beneath the press 40. By virtue of this arrangement, the excess water squeezed from the molded articles flows by gravity and with the help of the vacuum out of the chambers 54 (see FIGS. 6 and 7) in the plenum, through the openings 49 in the sides 50 of the plenum and downwardly through the arms into the tubular support to be collected for reprocessing and recycling. Thus, the excess water is kept from possibly being captivated in the plenum to rewet the articles after the latter are compacted by the press.

Once the dashboards 21 are compacted by the press 40, the main vacuum valve 39 is closed so the air entering the chambers 54 through the bleed ports 43 breaks the vacuum in the plenum 33, and the air in the bladders 129 is vented through the air lines 130. Then, the press head 124 is unclamped from the plenum 33 and is retracted into its out of the way position. The bleed ports 43 then are closed by de-energizing the solenoids 60.

To eject the dashboards from the molds 24, the plenum 33 is indexed on the arms 31, the plenum being pivoted into an inverted position relative to the arms. Then, pressurized air is forced into the two chambers 54 to below the dashboards off the molds and onto the conveyor 41. Herein, the plenum is mounted between the arms on two pins 144 (see FIGS. 2 and 7), each projecting outwardly from fixed connections to the op posite sides 50 ofthe plenum and journaled through the side walls 145 and 146 of each of the arms. Mounted on the outer wall 145 of one of the arms is a fluidactuated cylinder 147 (see FIG. 8) and a toothed rack 148 which is connected on the end of a reciprocable rod 149 projecting from the cylinder. The rack meshes with a pinion 150 secured to the outer end portion of the adjacent one of the pins 144 so that, as the rod is reciprocated in the cylinder, the rack is moved to turn the pinion and, in turn, the pin pivotally indexes the plenum relative to the arms. When advanced, the rod indexes the plenum in a clockwise direction (as shown in FIG. 8) to invert the plenum relative to the arms so the wall 56 and molds 24 face downwardly toward the conveyor 41.

By inverting the plenum 33 relative to the arms 31, the openings 49 in the opposite sides 50 of the plenum are moved out of alignment with the holes 51 in the inner walls 146 of the arms so that portions of the sides 50 of the plenum block the holes in the sides of the arms and thereby seal the chambers 54 in the plenum from the two branches 47 of the passage 35. At the same time, vertically extending wings 151 (FIG. 7) on the walls 146 of the arms block the openings 49 in the opposite sides 50 of the plenum (see FIG. 9) to seal the plenum from the outside. Ports 152 in the two wings normally are blocked by the sides of the plenum prior to inverting the latter relative to the arms but, when the plenum is inverted, the ports align with the openings 49 in'the sides of the plenum (see P16, 9). Air pressure lines 153 communicating between the ports and an air pressure source 128 provide the air for blowing the dashboards from themolds and onto the conveyor.

After the dashboards 21 are ejected from the molds 24, the plenum 33 is indexed by the rack 148 and pinion 150 back into its original position relative to the arms 31, and the latter are rotated by actuation of the motor 119 to carry the plenum and molds back to their positions above the retracted stock pan 26 (see FIG. 10). Thereafter, the sprayer 90 is advanced between the empty molds and the stock pan and is actuated to wash away any pulp fibers adhering to the outer faces 25 of the molds.

To wash away the pulp fibers, a plurality of elongated nozzles 154 (FIG. 12) are mounted within the shower tray 93 and extend parallel to the pipes 106. Each of the nozzles includes one end portion 155 extending through the end wall 97 of the tray and an opposite end portion 156 journaled in a block ,157 fixed to the other end wall 98. More particularly, the nozzles are attached to a manifold 158 around a plurality of outlets 159 by pivotable couplings 160. The manifold communicates with a high pressure water source (not shown) through an inlet 161 and is supported on the end wall 97 of the tray by a bracket 162. From the high pressure source, the water flows into the manifold and is divided thereby to flow into the nozzles. Each nozzle includes a plurality of orifices 163 which open upwardly toward the molds and which are spaced from each other along a substantial portion of the length of the nozzle. By pivoting the nozzles back and forth about their longitudinal axes, the water sprayed upwardly through the orifices washes back and forth across the outer surfaces 25 of the molds to cleanse the molds of pulp fibers possibly adhering thereto.

Herein, the means for pivoting the nozzles 154 in cludes a yoke 164 (FIG. 11) disposed below the nozzles and between the manifold 158 and the end wall 97 of the tray 93. A plurality of connectors 165 corresponding in number to the number of nozzles and comprising parts of the yoke extend upwardly from pivot connections 166 to a lower crosspiece 167 and are secured to the nozzles between the couplings 160 and the tray. Extending downwardly from the crosspiece is a fixed tongue 168 which is attached by a pivot 169 to a rod 170 projecting forwardly from a fluid-actuated cylinder 171 mounted on the underside of the bottom wall 100 of the tray by an L-shaped bracket 173. When the rod is reciprocated in the cylinder, the yoke moves back and forth thereby pivoting the nozzles to spray back and forth across the outer faces 25 of the molds 24. As with the low pressure spray, the water sprayed from the nozzles falls back into the tray 93 and is collected for reprocessing and recirculating and thus is kept from diluting the slurry 23in the stock pan 26. Once the molds are cleaned in the foregoing manner, the motor 105 is actuated to retract the shower tray from beneath the molds and into its normal rest position thereby completing one cycle in the operation of the molding machine 20.

By way of summary, it will be seen that the novel molding machine of the present invention operates in a unique manner to mold articles 21 such as the exemplary impact-crushable dashboards. To start the molding machine, the main vacuum valve 39 and the bleed ports 43 are opened and the vacuum regulator valve 61 is adjusted to obtain the desired thickness of the dashboards to be formed. Then, the molds 24 are immersed in the stock pan 26 by raising the latter with the main cylinders 36 so the vacuum applied to the plenum chambers 54 through the passage 35 draws the slurry 23 from the stock pan and through the molds, the latter serving to strain the pulp fibers from the slurry so that the fibers collect on the outer faces 25 of the molds to form the dashboards. Advantageously, the bleed ports 43 in the passage cushion the initial build-up of the vacuum so the larger and smaller pulp fibers collect uniformly on the molds throughout the thickness of each dashboard being formed. Moreover, the ported plates 44 in the stock pan between the immersion chamber 75 and the inlet chamber 74 keep the pulp fibers evenly distributed throughout the slurry in which the molds are immersed. The outside air drawn into the passage by the vacuum also is used to siphon the white water from the chambers 54 through the tubes 86 so the water may be removed from the plenum and recovered for reuse.

Once the dashboards 21 are formed on the outer faces 25 of the molds 24, the stock pan 26 is retracted and the sprayer 90 is advanced between the molds and the stock pan to spray low pressure water against the edges of the molds to wash away pulp fiber drippings. Thereafter. the sprayer is retracted and the arms 31 are pivoted by actuation of the motor 119 to carry the molds to their positions beneath the press 40. The press head 124 then is advanced to engage the upwardly facing wall 56 of the plenum and is clamped to the plenum. The bladders 129 on the head are inflated to squeeze excess water from the dashboards and, by virtue of the novel shape of the plenum and the arms, the excess water is squeezed from the dashboards flows by gravity out of the plenum and through the arms to be returned to the main supply of slurry with the help of the vacuum.

After squeezing the excess water from the dashboards 21, the vacuum valve 39 is closed so the air entering the chambers 54 through the bleed ports 43 breaks the vacuum in the plenum. The air in the bladders then is vented to permit the press head 124 to be unclamped from the wall 56 of the plenum. Then, after retracting the press head, the bleed ports are closed and the plenum is pivotally indexed on the arms 34 by the rack 148 and pinion 150 into an inverted position to seal the plenum from the passage 35 while at the same time unblocking the ports 152 through which pressurized air is forced into the chambers 54 to blow the dashboards off the molds 24 and onto the conveyor 41. Thereafter, the plenum is indexed back into its original position relative to the arms, and the arms are swung reversely to carry the plenum back into position above the stock pan 26. The sprayer then is ad vanced between the molds and the stock pan and high pressure water is sprayed from the nozzles 154 as the latter are pivoted back and forth across the outer faces 25 of the molds by operation of the cylinder 147 to wash away pulp fibers clinging to the molds. After cleansing the molds, the sprayer is rolled back to its normal rest position from beneath the plenum thereby to complete one cycle of the molding machine 20.

Another embodiment of the invention is illustrated in FIGS. 13 through 18 where parts corresponding to those described above are indicated by primed reference numerals. In this embodiment, a molding machine 20' operates in essentially the same manner as the molding machine 20, but includes two sets of arms 31 extending in opposite directions from each other from a rotatable support 46' (see FIG. 14). Advantageously, each of the sets of arms carries a plenum 33 thereby doubling the capacity of the molding machine 20 over that of the molding machine 20.

In the molding operation, the support 46' is rotated through a complete revolution, stopping each 90 as one of the basic steps of forming, draining, pressing or ejecting is performed. Herein, the support is rotated in a clockwise direction as viewed in FIG. 13, the arms being swung through successive 90 arcs beginning with the arms oriented vertically.

In the first position, articles 21 (FIG. 15) are formed on molds 24 carried in the lower plenum 33a while excess water is squeezed by a press 40 (FIG. 13) from the articles 21' carried in the upper plenum 33b. Thereafter, the stock pan 26' is retracted and a sprayer 90' is advanced between the stock pan and the newly molded articles to trim pulp fiber drippings from the edges of the mold with a low pressure water spray. After moving the sprayer back into its rest position to one side of the stock pan, the arms 31' are swung 90 clockwise into substantially horizontal positions and the two plenums are each indexed relative to their respective arms 90 in a clockwise direction (see FIG. 16) so the articles in the plenum 33a face upwardly for draining and the articles in the plenum 33'b face downwardly for ejection onto a conveyor 41' (FIG. 13). Once the draining and ejecting operations are performed, the plenums each are indexed back into their original positions and the arms are swung through another 90", placing the articles in the plenum 33'a in position for pressing and the molds in the plenum 33b in position for forming new articles from the slurry in the stock pan 26'.

After the articles in the plenum 33a are pressed and new articles are formed on the molds 24' in the plenum 33'b and trimmed of pulp fiber drippings by the sprayer 90' the arms 31' are swung another 90 clockwise and the plenums are indexed 90 clockwise relative to the arms, positioning the plenum 33'!) for draining and the articles in plenum 33'a for ejection from the molds onto the conveyor. Thereafter, the plenums again are indexed back to their original positions relative to the arms and the latter are swung clockwise through another 90 by the support 46 as it finishes rotating through one revolution. Then, to complete one cycle in the operation of the molding machine the sprayer again is advanced between the molds and the retracted stock pan, this time to spray high pressure water back and forth across the surfaces of the molds to cleanse the latter of adhering pulp fibers.

Because the various steps in the molding process take place at different times for each of the two plenums 33'a and 33b, the interior of the support 46' is divided,

into two separate passages 35a and 35'b (FIG. 14) by a partition I80 extending longitudinally through the support from a rotatable joint 68 to a closed end portion 112 of the support. A fixed pipe 63 (FIG. 17) leading from the joint to a vacuum pump 32' also is divded in half by a partition 181 which extends longitudinally through a portion of the pipe between the joint and two main vacuum valves 39a and 39b which are mounted in the passages 35'a and 35b respectively. In I the positions illustrated in FIG. 14, articles 21' are formed on the molds 24 by evacuating the air from the plenum 33'a and immersing the molds in the slurry by lifting the stock pan 2.6 with the cylinders 36 so the vacuum draws slurry through the molds causing the fibers in the slurry to collect on the outer surfaces 25' of the molds. At the same time, previously molded articles in theplenurn 33'b are squeezed by the press 40' to remove excess water from the articles.

With the arms 31 positioned vertically, both of the main vacuum valves 39' are open as are bleed ports 43' which are located adjacent the free ends of each of the arms. Also, regulator valves 6Ia and 61'!) (shown in FIG. 17) are located in each of the passages 35'a and 35'b, respectively, between the main vacuum and the rotatable joint 68' and are adjusted so as to achieve the desired predetermined thickness for the articles 21' being formed. In the vertical position of the arms, the partition 180 extends crosswise of the partition 181 (see FIGS. 13 and I4) so the white water evacuated from plenum 33'a may flow through either or both of the passages 35'0 and 35'b in the fixed pipe 63', past the main vacuum valves 39a and 39b to a separator tank 48' located between the main vacuum valve and the pump 32'. In the lower plenum 33'a, the white water in the chambers 54 is drawn from adjacent the wall 56' through siphon tubes 86 as a result of the outside air entering the branches 47' of the passage 35'a through the bleed ports 43'. In the upper plenum 33'b,

the water squeezed from the articles flows from the chambers in that plenum, through the arms and eventually to the separator tank with the white water drawn from thelower plenum.

Herein, the openings 49' and holes 51' in the end walls 50 of the plenums and the inside walls 146 of the arms 31, respectively, are arranged in a slightly different manner than the similar openings and holes in the first embodiment. Although each chamber54' includes two openings 49' located in the opposite end walls 50,

three holes 51 are formed in the inside walls of each arm so that, when the arms are in the molding and pressing positions, the two openings in the walls 50' of the plenums are aligned with two of the three openings in the arms the other holes in the arms being blocked by the adjacent sides of the plenums. Similarly, when the plenums are indexed 90 relative to their respective arms, such as when the plenums are positioned for draining and ejecting, the two openings'in the plenum walls still are aligned with two of the three holes in the arms (compare FIGS. 15 and 18).

After the articles 21' are formed on the molds 24' in the lower plenum 33'a, the stock pan 26' is retracted and the sprayer 90' is advanced from its normal rest position on a support 91' adjacent one side of the stock pan along the tracks 95 and 96' into position beneath the lower plenum by actuation of a motor After pulp fiber drippings have been washed away from the edges of the molds 24', the sprayer is retracted back to its rest position and the arms 31' are swung in a clockwise direction through a 90 are by rotation of the support 46. As in the first embodiment, the support is rotated by a motor 119' which drives gears 123' and 117'. As the support rotates the arms 31 into horizontal positions, the partitions and 181 align with each other (see FIGS. 16 and 17) and the plenums each are indexed 90 in a clockwise direction by actuation of cylinders I47 so the wall 56' of the plenum 33 a faces upwardly and the wall 56' of the plenum 33b faces downwardly.

With the two partitions 180 and 181 aligned with each other, the passages 35'a and 35b are sealed from each other so that the vacuum still may be applied to the chambers 54' of plenum 33'0 while pressurized air is forced into thechambersof plenum 33'b. This is accomplished by leaving the main vacuum valve 39a open and closing the vacuum valve 39'b along with the bleed ports 43 which open into the passage 35'b. Then, to blow the articles off the molds 24' and onto theconveyor 41', pressurized air is forced into passage 35'b, through the aligned holes SI and openings 49' through the walls 146' and 50 of the arms and plenum, respectively, and into the chambers 54'. The conveyor 41' then carries the articles away for further processing. In this embodiment, only one pressure line 153' (FIG. 17) is used to deliver pressurized air from an air pressure source 128'. Herein, the line is connected to the passage 35'b between the regulator valve 61'!) and the joint 68' thereby avoiding separate connections between the air pressure source and each of the two plenums 33a and 33'b.

With the plenum 33'a in position for draining, any white water left in that plenum and the arms 21' flows, with the help of the vacuum, into the passage 35'a and toward the separator tank 48'. Advantageously, each of the plenums is shaped in such a fashion so as to facilitate drainage of the white water toward the support pipe 46. ln each plenum, a wall 142 opposite the lower wall 56 is comprised of two sections 183 and 184 (H6. 18), one covering one of the chambers 54' in the plenum and the other section covering the other chamber. Each of the sections slants toward the lower wall upon progressing outwardly from the center of the plenum. Thus, when the plenums are positioned for draining, the white water drains toward the center of the plenums through the aligned openings 49 and holes 51 and into the arms 31' both as a result of the vacuum and gravity.

Once the draining and ejecting steps of the molding process are completed, the plenums 33'a and 33b are indexed back to their original positions relative to their respective arms 31. At this point, an extension 185 (FIG. 13) of the conveyor 41 is pivoted counterclockwise into a position as shown in FIG. 13 to locate the extension out-of-the-way so the plenum 33'b may be swung into position above the retracted stock pan 26. Herein, the extension comprises a plurality of belts 186 trained around rollers 187 and driven by a roller 188 which also serves as the end roller of the stationary portion of the conveyor. A pivotal arm 189 connected between the rollers is supported vertically by a rod 190 extending outwardly of a cylinder 191 which is mounted on a member 192 supporting the conveyor. The outer end of the rod is pinned to the outer end of the arms and normally is advanced from the cylinder so the belts are supported horizontally to receive the articles 21' blown from the molds 24.

To move the conveyor extension 185 out of the way, the rod 190 is retracted within the cylinder 191, thereby pulling the arm 186 downwardly in a counterclockwise direction as shown in FIG. 13 so the arms 31' may be swung past the conveyor to position the plenum 33' above the stock pan 26' and the plenum 33a below the press 40'. Once the arms are again oriented vertically, the cylinder is actuated to advance the rod and thereby reposition the conveyor extension so that it extends in a horizontal position. At about the same time, the forming and pressing steps are repeated with new articles being formed on the molds 24' being car'- ried by plenum 33); and the articles carried by plenum 33'a being squeezed of excess water by the press 40.

Thereafter, the arms 31' are swung another 90 clockwise and the plenums are indexed. carrying the plenum 33'b into its draining position and the plenum 33'a into position for ejecting the articles 21' from the molds 24' in that plenum. It will be appreciated that in these positions, the partitions 180 and 181 again are aligned with each other so the portions of the passages 35'a and 35'b within the support 46' now align with the stationary portions of the passages 35'b and 35'a, respectively, leading to the separator tank 48' and pump 32'. Accordingly, the portion of passage 35'b extending from the main vacuum valve 39'!) to the joint 68' is alternately pressurized and subjected to vacuum during the molding process while the portion of the passage 35a extending from the main valve 39'a to the joint 68' is continually subjected to vacuum.

Once the plenum 33'b is drained of excess white water and the articles 21' are ejected from the molds 24' on the plenum 33a and carried away by the conveyor 41', the latter is moved into its out-of-the-way position and the plenums are indexed 90 counterclockwise to be swung with the arms 31' through 90 arcs so plenum 33a is positioned above the stock pan 26 and the plenum 33b is positioned below the press. The conveyor then is swung back into its horizontal position and the sprayer is advanced from its support 91' and into position between the plenum and the stock pan for spraying high pressure water back and forth across the outer faces of the molds 24' to cleanse the latter of pulp fibers adhering to the molds. One cycle of the molding operation of the molding machine 20, then is completed by retracting the sprayer from between the stock pan 26 and the plenum 33'a preparatory to the beginning of the next cycle.

We claim as our invention:

1. A machine for molding an article from a pulp slurry, said machine including a frame, an arm mounted on said frame, a perforate mold on said arm for forming said article from the pulp in the slurry, a vacuum source communicating with said mold through a passage, a stock pan containing said slurry mounted on said frame and being movable relative to said mold from a retracted position to an advanced position to immerse said mold in the slurry whereby the slurry is drawn from said pan by said vacuum to form said article on the mold, means for controlling the molding of the article so that the density of the pulp throughout the thickness of the article is relatively uniform, said means including a bleed port opening into said passage and permitting outside air to be drawn into said passage by said vacuum so the vacuum applied to said mold builds up gradually, a press mounted on said frame and adapted to squeeze excess water from the article after the latter is formed on the mold, means for rotating said arm on said frame to carry said mold between said stock pan and said press, and means for ejecting said article from the mold after the excess water is removed from the article.

2. A machine for molding an article froma pulp slurry, said machine including a frame, an arm mounted. on said frame, a mold supported adjacent one end of said arm, a vacuum source, a passage extending between said vacuum source-and said mold, a stock pan containing said slurry, mounted on said frame and having an inlet to receive said slurry from a supply, means for lifting said stock pan from a lower position intoan upper position to immerse said mold in the slurry, valve means in said passage movable from a closed position into an open position so said slurry is drawn from said stock pan by said vacuum to form said article on said mold, a plurality of ported plates disposed within said stock pan adjacent said inlet to streamline the flow of slurry into said pan to keep the pulp uniformly distributed throughout the slurry, a bleed port in said passage permitting outside air to be drawn into said passage by said vacuum so the vacuum applied to said mold builds up gradually to keep the pulp density relatively uniform throughout the thickness of the article being formed, means for trimming excess pulp from the mold after the article is formed on the mold, a press mounted on said frame, means for rotating said arm on the frame to move said mold between said press and said stock pan, said press including a head, a clamp connectable between said head and said mold to hold the mold and head together, a bladder mounted on said head and adapted to be inflated to squeeze excess water from said article, an air pressure source, a normally blocked pressure line communicating between said pressure source and said mold, and means for unblocking said line after squeezing excess water from the mold so air from said pressure source blows said article off the mold, said trimming means including a shower tray mounted on said frame and adapted to move from a first position adjacent one side of said stock pan into a second position above the retracted position of said stock pan when said mold is positioned above the pan, and a plurality of nozzles carried by said tray and adapted to spray water on the mold tocleanse the latter of pulp adhering to the mold after said article is blown from the'mold and prior to molding another article.

3. A machine for molding an article from a pulp slurry, said machine including a frame, a movable arm mounted on said frame, a perforate mold carried by said arm to form said article from the pulp in the slurry,

a vacuum source communicating with said mold' through a passage in said arm, a stock pan mounted on said frame and including an immersion tank having an open upper end and a lower inlet through which said slurry flows into said tank from a supply, said stock pan being movable relative to said mold to immerse the latter in the slurry contained in said tank whereby slurry is drawn from said tank by the vacuum to form said article on said mold, means for keeping the pulp uniformly distributed throughout the slurry in said immersion tank, a bleed port in said arm opening into said passage to permit outside air to be drawn into said passage by the vacuum so that vacuum applied to said mold builds up gradually to keep the pulp density relatively uniform throughout the thickness of the article being formed, a press mounted on said frame, means for rotating said arm on said frame to move said mold between said press and said stock pan, said press being engageable with said article to squeeze excess water from the article, and means for ejecting the article from the mold after the excess water is removed.

4. A machine as defined by claim 3 including means for indexing said mold relative to said arm between selected positions for molding and ejecting.

5. A machine as defined by claim 4 including a plenummounted on said arm adjacent one end thereof, said mold being mounted on said plenum, and a tube within said plenum coacting with the outside air to siphon water from the plenum and into said passage as said article is formed on the mold.

6. A machine as defined by claim'5 wherein said pulp distribution means includes a plurality of plates mounted within said immersion tank adjacent said inlet and having a series of holes for streamlining the flow of slurry into said tank.

7. A machine as defined by claim 6 wherein said plenum includes opposite side walls, front and rear walls, an upper wall, and a lower wall opposite said upper wall and having an opening therein, said mold being secured to said lower wall within said opening.

8. A machine as defined by claim 7 wherein said upper wall tapers toward said lower wall upon progressing from the rear wall toward said front wall so that, as said arm is rotated to move the mold to said press, said lower wall is moved into an upwardly facing position and said upper wall is moved into a downwardly facing position slanted relative to horizontal whereby the water squeezed from said article by said press flows by gravity out of said plenum and into said passage to keep said article from being rewetted after pressing.

9. A machine as defined by claim 7 wherein said bleed port is located in said arm adjacent said plenum and further including a valve for selectively opening and closing said port.

10. A machine as defined by claim 9 including a removable cap having a central opening of predetermined size, and cap being positioned on said arm to restrict the flow of air through said port and into said passage.

11., A machine as defined by claim 10 including a valve in said passage between said plenum and said vacuum source and movable between open and closed positions to connect and disconnect the interior of the plenum with the vacuum source, a regulator in said passage between said plenum and said latter valve for selectively controlling the level of the vacuum applied to the interior of the plenum through said passage.

12. A machine as defined by claim 11 including an opening in one wall of said plenum, a corresponding hole in said arm and aligned with the opening in said plenum so the passage communicates with the interior of said plenum, and a seal around said opening between said arm and said one wall.

13. A machine as defined by claim 7 including two of said arms spaced from and extending parallel with each other, a support pipe connected between the ends of said arms opposite said plenum, the interior of said pipe communicating with the interior of each of said arms to define a portion of said passage, pins projecting from each side wall of the plenum and connecting with said arms to mount said plenum between said arms for indexing relative thereto between said selected positions for molding and ejecting.

14. A machine as defined by claim 13 wherein each of said arms includes spaced, parallel side walls and top and bottom walls tapering toward each other'upon pro-' gressing from adjacent said plenum toward said pipe to facilitate the flow of excess water squeezed from said article through said arms and into said pipe.

15. A machine as defined by claim 13 wherein said arm rotating means includes a motor mounted on said frame adjacent said pipe, gear means connected between said motor and said pipe, said motor being selectively operable to rotate said pipe about-a'substantially horizontal axis to rotate said arms from said stock pan to said press.

.16. A machine as defined by claim 15 including a counterweight mounted on said pipe opposite said'arms and extending away from said pipe.

17. A machine as defined by claim 15 including a second set of arms mounted on said pipe opposite said first arms, said second set extending away from said pipe and supporting a second plenum and mold for forming said articles.

18; A machine as defined by claim 13 wherein said stock pan includes an outer tank having a lower outlet for returning slurry to said supply, said immersion tank fitting within said outer tank, a return passage defined by the space between said outer tank and the immersion tank and communicating between the top edge of tank across the upper opening of said lower chamber.

20. A machine as defined by claim 19 wherein said lower chamber further includes a lower outlet opposite said inlet and having a bottom slanting downwardly from said outlet toward said inlet whereby the crosssectional area of said chamber becomes smaller upon progressing toward said outlet from the inlet to help maintain relatively even pressure in the slurry flowing through all of said plates.

21. A machine as defined by claim 18 including fluidactuated means for moving said stock pan between a retracted position and an advanced position to immerse the mold in the slurry.

22. A machine as defined by claim 20 including a sprayer adapted to cleanse the edges of said mold of pulp drippings prior to squeezing excess water from said article.

23. A machine as defined by claim 22 wherein said sprayer includes a shower tray mounted on said frame to move from a first position adjacent one side of said stock pan into a second position above the retracted position of said stock pan, a plurality of pipes carried by said tray and having upwardly facing small openings for spraying water on the edges of said mold.

24. A machine as defined by claim including an air pressure source, a normally blocked pressure line communicating between said pressure source and said plenum, and means for indexing said plenum on said arm from said molding position into said ejecting position to unblock said line and to seal said plenum from the outside air whereby said pressurized air fills said plenum to blow said article off the mold.

25. A machine as defined by claim 22 wherein said sprayer further is adapted to cleanse said mold of pulp adhering thereto after the article is ejected from the mold and prior to molding the next article.

26. A machine as defined by claim 25 wherein said sprayer includes a shower tray mounted on said frame to move from a first position adjacent one side of said stock pan into a second position above the retracted position on said stockpan, and a plurality of nozzles carried by said tray and adapted to spray water on the mold.

27. A machine as defined by claim 25 wherein said sprayer further includes a manifold mounted on one end of said tray and having an inlet opening communicating with a high pressure water source and a plurality of outlet openings, said nozzles extending outwardly of said manifold from said openings and each nozzle being pivotally supported at opposite ends thereof within said tray and having a plurality of orifices for spraying water onto said mold, and means for turning said nozzles about their longitudinal axes to spray back and forth across the surface of said mold.

28. A machine for molding an article from a pulp slurry, said machine including a frame, an arm mounted on said frame, a perforate mold on said arm for forming said article from the pulp in the slurry, a vacuum source communicating with said mold through a passage, a stock pan containing said slurry mounted on said frame and being movable relative to said mold from a retracted position to an advanced position to immerse said mold in the slurry whereby the slurry is drawn from said pan by said vacuum to form said article on the mold, means for controlling the molding of the article so that the density of the pulp throughout the thickness of the article is relatively uniform, a press mounted on said frame and adapted to squeeze excess water from the article after the latter is formed on the mold, means for rotating said arm on said frame to carry said mold between said stock pan and said press, means for ejecting said article from the mold after the excess water is removed from the article, and indexing means for turning said mold relative to said arm between selected positions for molding and ejecting.

29. A machine for molding'an article from a pulp slurry, said machine comprising a frame, an arm pivotally mounted on said frame, a perforate mold pivotally mounted on said arm, a supply of slurry, means for immersing said mold in said supply, means for sucking the slurry from said supply and onto and through the immersed mold to form the article thereon, means for pivoting said arm on said frame after formation of said article on said mold, a press for thereafter engaging said article to squeeze excess water therefrom, indexing means for thereafter pivoting said mold relative to said arm to turn said mold to an ejecting position, and

means for ejecting the article from said mold when the latter is in said ejecting position.

30. A machine as defined in claim 29 further including a second arm pivotally mounted on saidframe and projecting oppositely from said first arm, means connecting said arms for turning in unison, a second mold pivotally mounted on said second arm, and means for pivoting said second mold relative to said second arm.

31. A machine as defined in claim 30 in which said arms are mounted on said frame to turn about a generally horizontal axis and are free to turn through a complete circle, said supply of slurry being located at the bottom of said circle and said press being located at the top of said circle.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2234979 *Apr 29, 1937Mar 18, 1941Canal Nat Bank Of PortlandApparatus for producing molded pulp articles
US2663230 *Nov 17, 1948Dec 22, 1953Jean WagnerApparatus for automatic withdrawing of pulp articles from molds
US2990314 *Oct 2, 1956Jun 27, 1961Pacific Pulp Molding CompanyPulp molding method and apparatus
US3016091 *Aug 11, 1960Jan 9, 1962Diamond National CorpVacuum control for pulp molding machines
US3066069 *May 1, 1959Nov 27, 1962Fredrik Ednell DanielMethod for the producion of refractory containers
US3507746 *Mar 22, 1967Apr 21, 1970Texas Instruments IncAutomatic vacuum suction box in papermaking
US3567575 *Apr 6, 1967Mar 2, 1971Keyes Fibre CoApparatus for producing fibrous pulp articles
US3594273 *May 15, 1967Jul 20, 1971Amf IncSequential accretion of plural-fiber articles
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3922191 *May 23, 1974Nov 25, 1975Diamond Int CorpApparatus for molding articles with multiple basis weight or thickness
US4162935 *May 31, 1977Jul 31, 1979Idra AgPapier-mache coffin and method of making it
US5335770 *Aug 6, 1992Aug 9, 1994Moulded Fibre Technology, Inc.Molded pulp fiber interior package cushioning structures
US5656135 *Feb 16, 1993Aug 12, 1997Moulded Fibre Technology, Inc.Molded product manufacturing apparatus and methods
US6048440 *Jul 21, 1997Apr 11, 2000Moulded Fibre Technology, Inc.Molded product manufacturing apparatus and methods
US6103179 *Dec 12, 1996Aug 15, 2000Celtec Development AbMethod and arrangement for producing a fibre product
US6716319 *Sep 18, 2001Apr 6, 2004Regale CorporationMolded pulp product and apparatus and method for producing the same
US7678307Nov 3, 2006Mar 16, 2010Materials Innovation Technologies, LlcVortex control in slurry molding applications
US7909964Nov 25, 2005Mar 22, 2011Pakit International Trading Company Inc.Pulp mould and use of pulp mould
US8246784Mar 21, 2011Aug 21, 2012Pakit International Trading Company Inc.Pulp mould and use of pulp mould
EP0242848A2 *Apr 21, 1987Oct 28, 1987Fel-Pro IncorporatedGasket forming process
EP0466653A1 *Jul 5, 1991Jan 15, 1992Alois KochProcedure for manufacture of a coffin from formed pulp material
EP1721042A1 *Sep 20, 2002Nov 15, 2006Regale CorporationMolded pulp product and apparatus and method for producing the same
WO1994019540A1 *Feb 16, 1994Sep 1, 1994Moulded Fibre Technology IncMolded product manufacturing apparatus and methods
WO2004027154A1 *Sep 20, 2002Apr 1, 2004Edward D AllowayMolded pulp product and apparatus and method for producing the same
WO2007106026A1 *Mar 9, 2007Sep 20, 2007Torbjoern HanssonDevice and method relating to fibre moulding
Classifications
U.S. Classification162/391, 162/228, 162/410, 162/393, 162/411
International ClassificationD21J5/00
Cooperative ClassificationD21J5/00
European ClassificationD21J5/00