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Publication numberUS3866641 A
Publication typeGrant
Publication dateFeb 18, 1975
Filing dateSep 20, 1973
Priority dateSep 20, 1972
Also published asCA985002A1, DE2347277A1, DE2347277B2
Publication numberUS 3866641 A, US 3866641A, US-A-3866641, US3866641 A, US3866641A
InventorsKitani Koichi, Mizu Koichi, Mori Yubi
Original AssigneeMatsushita Electric Ind Co Ltd
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Fluid-operated fastener feeding apparatus
US 3866641 A
Abstract
A fluid-operated fastener feeding apparatus for use in association with a power operated fastening tool essentially comprising a hopper section including a fastener receiving funnel accommodating therein a plurality of fasteners and a rotary drum for upwardly scooping fasteners from the bottom of the fastener receiving funnel, a downwardly included track having an upper portion held in position to receive the fasteners that have been upwardly scooped by the rotary drum during rotation of the rotary drum, an escapement assembly for successively separating the fasteners that have been downwardly guided along the track and then to feed each fastener to the fastening tool, these essential components of the apparatus being fluid operated.
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Description  (OCR text may contain errors)

United States Patent [191 Mizu et al.

FLUID-OPERATED FASTENER FEEDING APPARATUS Inventors: Koichi Mizu; Koichi Kitani; Yubi Mori, all of Osaka, Japan Matsushita Electric Industrial Co., Ltd., Osaka, Japan Filed: Sept. 20, 1973 Appl. No.: 399,136

Assignee:

Foreign Application Priority Data Sept. 20, 1972 Japan 47-94757 Sept. 20, 1972 Japan 47-94758 Sept. 20, 1972 Japan 47-94769 US. Cl 144/32, 221/9, 227/116 Int. Cl B25b 23/00 Field of Search 221/9, 10; 144/32; 29/211,

References Cited UNITED STATES PATENTS 8/1966 Janus 227/116 2/1967 Willis [111 3,866,641 [4 1 Feb. 18, 1975 3,583,451 6/1971 Dixon 144/32 3,642,039 2/1972 McGee 3,779,422 12/1973 Mori 221/10 Primary Examiner-Andrew R. Juhasz Assistant Examiner-W. D. Bray Attorney, Agent, or Firm-Wenderoth, Lind & Ponack [57] ABSTRACT A fluid-operated fastener feeding apparatus for use in association with a power operated fastening tool es sentially comprising a hopper section including a fastener receiving funnel accommodating therein a plu- 7 Claims, 24 Drawing Figures PATENTEU FEB 1 81975 3 866 641 SHEET 2 OF 9 PATENTED FEB I 8 I975 SHEET 3 OF 9 PMENTEDFEBI 8|975 3.866.641

sums 0F 9 FIG. 86

FIG. 9a

Pmmm EB 1975 E OE) E FLUID-OPERATED FASTENER FEEDING APPARATUS The present invention relates to a fluid operated fastener feeding apparatus and, more particularly, to a fluid operated fastener feeding apparatus for use in association with a power operated fastening tool such as screw driver, riveting tool or the like, wherein a plurality of fasteners are automatically supplied one by one to the fastening tool in a timed manner with respect to the operation of the fastening tool.

A prior art fastener feeding apparatus of a similar kind is known which employs electrical power for controlling the supply of a plurality of fasteners and also employs a fluid source for controlling operation of an escapement assembly and a fastening tool. The employment of two different power sources in the conventional fastener feeding apparatus has many disadvantages: trouble often occurs therein, thus reducing the reliability, and the cost to manufacture is relatively high.

Accordingly, an essential object of the present invention is to provide a fluid operated fastener feeding apparatus wherein improvement over the conventional apparatus of the same kind has been made by making all of the components fluid-operated.

Another object of the present invention is to provide a fluid operated fastener feeding apparatus of the aforementioned type which can be manufactured at relatively low costs and which will operate substantially trouble free.

A further object of the present invention is to provide a fluid operated fastener feeding apparatus of the aforementioned type whereby a rotary drum for supplying fasteners from the bottom of a fastener receiving funnel is rotated by a cylinder through a motion translator for translating linear motion into rotary motion.

A still further object of the present invention is to provide a fluid operated fastener feeding apparatus having a downwardly inclined track for guiding a plurality of fasteners in a row, said track being provided with a pair of fluid flow detectors for detecting the presence or absence of the row of the fasteners on the track 5, for controlling the operation of the cylinder and for rotating the rotary drum.

A still further object of the present invention is to provide a fluid operated fastener feeding apparatus of the aforementioned type having an escapement assembly for successively separating the fasteners being downwardly guided along the track in a row and then to supply each fastener to the fastening tool in response to operation of the fastening tool, said escapement assembly being constructed with the minimum possible number of parts.

A still further object of the present invention is to provide a fluid operated fastener feeding apparatus of the aforementioned type wherein, for the purpose of the fluid operation of the apparatus, the fluid flow detectors are designed for fluid operation as are the es capement assembly and the rotary drum, thereby substantially improving in the lifetime and reliability of the apparatus itself.

These and other objects and features of the present invention will become apparent from the following description taken in conjunction with a preferred embodiment thereof with reference to the accompanying drawings, in which;

FIG. 1 is a schematic perspective view of a fluid operated fastener feeding apparatus according to the present invention,

FIG. 2 is a view similar to FIG. 1, but showing the apparatus viewed from different position,

FIG. 3(a) is a side view of FIG. 3(b),

FIG. 3(1)) is a frontal elevation of a rotary drum showing a linkage between it and a fluid operated cylinder,

FIG. 3(0) is a schematic diagram, on an enlarged scale, showing a connection between a rachet member and a link,

FIG. 4(a) is a front elevation of a modified rotary drum showing a linkage between it and a fluid operated cylinder,

FIG. 4(b) is a side sectional view, on an enlarged scale, of a portion of a link carrying a rachet member in the arrangement of FIG. 4(a),

FIG. 5 is a frontal elevation of a further modified rotary drum showing a linkage between it and a fluid operated cylinder,

FIG. 6(a) is a perspective view of a fluid controller employed in the apparatus,

FIG. 6(b) is an exploded view of the fluid controlled shown in FIG. 6(a),

FIGS. 7(a) and (b) are side sectional views of the fluid controlled of FIG. 6(a) showing if in different operational positions, respectively,

FIG. 8(a) is a perspective view of one of the fluid flow detectors employed in the apparatus of the present invention,

FIG. 8(b) is a top view of a portion of the track showing the arrangement of the fluid flow detector of FIG.

FIG. 8(0) is a cross sectional view of the fluid flow detector designated by A in FIG. 8(a),

FIG. 9(a) is a perspective view of an escapement as sembly employed in the apparatus of the present inventron,

FIG. 9(b) is a cross sectional view of the escapement assembly shown in FIG. 9(a) as designated by A in FIG.

FIG. 9(0) is a top view, on an enlarged scale, of the escapament assembly,

FIG. 10 is a perspective view of a screw driver employed in the apparatus of the present invention,

FIG. I1 is a perspective cut away view of a fluid sig nal generator fitted to the screw driver of FIG. 10,

FIGS. 12(a) and (b) are longitudinal cross sectional views of the fluid signal generator, showing the genera tor in different operating positions,

FIG. 13 is an exploded view of the fluid signal generator shown in FIG. 11, and

FIG. 14 is the fluid circuit diagram of the apparatus of the present invention representing the control mech anisms or the various components of the apparatus.

Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings.

Referring now to the accompanying drawings and, particularly, to FIGS. 1 and 2, a fluid operated fastener feeding apparatus according to the present invention comprises a bench framework 1 including a hopper section. The hopper section comprises a fastener receiving funnel 2, integrally formed with, or otherwise rigidly mounted on, said framework 1 at the top thereof and a rotary drum 4, including a disc portion 4a and a peripheral rim portion 4b integrally extending from the periphery of said disc portion 4a at a right angle to the plane of said disc portion 4a. The rotary drum 4 is rotatably fastened to a bearing bracket 20, integrally formed with said framework 1, by a shaft 19 in such a manner that the interior space defined by the disc portion 4a and the peripheral. rim portion 4b faces the fastener receiving funnel 2.

The rotary drum 4 further includes a plurality of scoppers 3 equally spaced with respect to each other, each being secured to the inner surfaces of either or both the disc portion 4a and the peripheral rim portion 4b. These scoopers 3 act to scoop some of the fasteners within the funnel 2 upwardly and subsequently cause them to fall by gravity into the chute section (as will be mentioned later) as said rotary drum 4 is rotated about the axis of the shaft 19.

The chute section comprises a guide track composed of a pair of spaced rails 5a, 5b and having one end held in position within the funnel mouth 2 for receiving in succession each of the lots of fasteners that have been carried by the corresponding scoppers 3 and gravity fed thereinto as the rotary drum 4 is rotated. The other end of the chute section is connected with an escapement assembly (as described later) for successively transferring each of the fasteners carried by the track 5 into a power operated fastening tool, Le, a power operated screw driver. The chute section further comprises an impeller 50 for positively removing fasteners from the track 5 which are incorrectly mounted or displaced from the track, thereby avoiding the possibility of blocking the track 5.

The details of the mechanical arrangement so far described are disclosed in the copending US. Patent application, Ser. No. 273,020 filed on July 18, 1972 by the same assignee, now US. Pat. No. 3,779,422, which is directed to a fastener feeding apparatus of the same kind employing not only electrical power, but also fluid means, for operating the apparatus. Therefore, for the sake of brevity, the details section each of the hopper section and chute section, are not described in the subsequent description and reference may be made to the above numbered pending patent application.

Hereinafter, a drive mechanism for rotating the rotary drum 4 will be described with particular reference to FIGS. 2, FIG. 3(a), FIG. 3(b) and FIG. 3(c).

The drive mechanism for the rotary drum 4 comprises an air cylinder 7 supported in position by a support plate 8 secured to the bench framework 1 and formed with a cylinder bracket 9 rigidly carrying said air cylinder 7. The air cylinder 7 includes a cylinder rod 10 rigidly mounted with a trigger block 11 at a substantially intermediate position thereof and, also, mounted with a bearing block 12 at the free end thereof. Adjacent said trigger block 11 and spaced from the cylinder rod 10, a fluid contler 13 is attached to the bench framework 1, and used for generating a fluid signal to control the operation of the cylinder 7, said signal acting in response to the reciprocal movement of the trigger block 11 attached to the cylinder rod 10, as will be described later.

The bearing block 12 at the free end of the cylinder rod 10 has pivotally connected thereto by a pin member 15 a pair of lower links 14a, 14b, each link 14a, 14b having pivotally connected thereto at its other end a rachet member 16a, 16b connected by a pin member 18a, 18b. The disc portion 4a of the rotary drum 4 is integrally formed, or otherwise mounted, with a geared wheel 24 coaxial with the longitudinal axis of the shaft 19, and the respective tips of the rachet members 16a, 16b are meshed with the geared wheel 24 in such a manner as described later.

A pair of upper links 17a, 17b is pivotally connected to the shaft 19 and also to the lower links 14a, 14b by pin members 18a, 18b. Thus, this connection of links 14a, 14b, 17a, 17b forms substantially a pantograph arrangement.

The rachet members 16a, 16b are also connected by pin members 18a, 18b to the upper links 17a, 17b in the same manner as connected to the lower links 14a, 14b, thereby enabling said rachet members 16a, 16b to engage with the geared wheel 24. Only the connection between the one rachet member 16a and one link 17a will be described because the other rachet 16b and link 1712 combination works the same way. As best shown in FIG. 3(c), the nail member is provided with a pin member 21a projecting towards the link 1711 and, similarly, the link 17a is provided with a pin member 22a projecting towards the nail member 16a. A tension spring 23a is tensioned between said pin members 21a, 22a so that the tip of the rachet member 16a is constantly engaged with the geared wheel 24. It is to be noted that the rachet members 16a, 16b are oriented in the same direction with respect to the direction of rotation of the rotary drum 4.

In the above arrangement each time the cylinder rod 10 raises and lowers, the rachet members 16a and 16b alternately drive the geared wheel 24, thereby rotating the rotary drum 4 in one direction. More particularly, assuming that the cylinder rod 10 is retracted as shown in FIG. 3(b), if the cylinder rod 10 is subsequently projected, the bearing block 12 movesclose to the shaft 19, and the space between the pin members 18a and 18b gradually expands. At this time, the rachet member 16a engages the geared wheel 24 while the rachet member 16b successively skips over the geared wheel 24. Rotation of the rotary drum 4 is then caused by the engagement of rachet member 16a with the geared wheel 24 during the movement of the cylinder rod 10 from the retracted position to the extended position. During subsequent return movement of the cylinder rod 10 from the extended position to the retracted position, the rachet member 16b engages the geared wheel 24 while the nail member 160 successively skips over the geared wheel 24 and, hence, rotation of the drum 4 in the same direction is caused by the engagement of rachet member 16b. Thus, it has now become apparent that each reciprocation of the cylinder rod 10 results in the continuous rotation of the rotary drum 4 in one direction.

The drive mechanism may be modified as shown in FIGS. 4(a) and (b) and FIG. 5, respectively. In the example shown in FIGS. 4(a) and (b), instead of employing the geared wheel 24, an annular ring plate 25 having one face secured to the disc portion 4a of the rotary drum and the other face formed with a geared portion 25a is employed. In this instance, each of the links 17a, 17b, employed is a round rod with both ends flattened. The rachet members 16a, 16b are respectively rotatably mounted on these links 17a, 17b in alignment with the annular ring plate 25. As best shown in FIG. 4(b), in which only one of the nail member 16b rotatably mounted on the link 17b is illustrated, the nail member 16b is biased about the axis of the link 17b by a tension spring 33 suspended between two pins 31, and 32 secured to the rachet member 16b, so that the tip of the rachet member 16b is engaged with the geared portion 25a. The same is true of the other rachet member 16a.

This drive mechanism of FIGS. 4(a) and (b) satisfactorily functions in a manner similar to that shown in FIGS. 3(a), (b) and (0), without substantial reduction in performance.

In the example shown in FIG. 5, the drive mechanisim includes a link 26 having one end pivotally connected to the bearing block 12 and the other end carrying a rachet member 16 in the same way as either of the rachet members 16a, 16b in the example shown in FIGS. 3(a), (b) and (c). The link 26 is rotatably mounted at a substantially intermediate position in the link onto the shaft 19. In this example of FIG. 5, only when the cylinder rod is moved from the retracted position to the extended position can the rotary drum 4 be rotated about the axis of the shaft 19 in one directron.

The fluid controller 13 for automatically controlling the operation of the air cylinder 9 in response to the reciprocal movement of the cylinder block 11 is illustrated in detail in FIGS. 6(a) and (b) and FIGS. 7(a) and (b) and will now be described with particular reference to these drawings. I

The fluid controller 13 comprises a solid body 39 having therein a channel-shaped guide groove 40 extending parallel to the longitudinal axis of said solid body 39. A slider 41 having a cross section similar to the guide groove 40 is slidably fitted into said guide groove 40 and has a projection 51, which may be in the form of a cylinder-headed screw tapped into said slider 41, at a substantially intermediate portion of said slider 41. The guide groove 40 also accommodates therein a slidable plate 43 having both ends bent to form two respective angles 43a 43b, said slidable plate 43 being fitted into the guide groove 4D in such a manner that the corresponding tips of said angles 43a, 43b are slidably in contact with the slider 41, while the body of said slidable plate 43, spaced from said slider 41. These engagements 43a, 43b are alternately engageable with the projection 42 on the slider 41 in a manner as will be described later for reciprocating the slider 41 within the guide groove 40.

The slidable plate 43 is formed therein with a longitudinally extending guide slot 45 into which a cylindrical pin member 44, pressure-fitted to or otherwise integrally formed with the cylinder block 11, is slidably engaged. In this arrangement, assuming that the cylinder rod 10 is retracted and the cylinder block 11 is in position with the pin member 44 situated at a lower portion of the guide slot 45, subsequent movement of the cylinder rod 10 from the retracted position towards the extended position causes the pin member 44 to travel within the guide slot 45 towards the upper portion thereof. Upon arrival of the pin member 44 at the upper portion of the guide slot 45, further movement of the cylinder rod 10 causes movement of the slidable plate 43 with the angle 43a separating from the projection 42. When elevation of the slidable plate 43 is completed, the angle 43b engages with the projection 42 and, therefore, until the cylinder rod 10 arrives at the fully extended position, the slider 41 is upwardly moved, guided by the slidable plate 43. A similar operation takes place in the reverse order during thereturn movement of the cylinder rod 10.

It should be noted that various changes are possible in connecting the cylinder block 11 to the slider 41. By way of example, without employing the slidable plate 43, the slider 41 'may be formed with a guide groove, corresponding in function to the guide slot 45, into which the pin member 44 carried by the cylinder block 11 is engaged. In another example, the pin member 44 carried by the cylinder block 11 may be directly connected to the slider 41 in any suitable method. However, the arrangement shown in FIGS. 6(a) and (b) is particularly advantageous in that the fluid controller 13 can be manufactured in a relatively compact size with out requiring the slider 41 to travel in a distance corresponding to the stroke of movement of the cylinder rod 10.v

Referring still to FIGS. 6(a) and (b) and FIGS. 7(a) and (b), the solid body 39 is formed with a pair of coaxially aligned passages 46a and 46b, each substantially extending at right angles to the longitudinal axis of the solid body 39 and having one end opened towards the guide groove 40 and the other end opened towards the atmosphere. The solid body 39 is further formed at the opening of one of these passages to the atmosphere, with a threaded opening 47 for connection with a coupler 38 leading from an air discharge tube 52. Also, the slider 41 is formed with a passage 48 extending thereacross at right angles to the longitudinal axis of said slider 41, both ends of said passage being respectively alignable with the passages 46a and 46b, when the slider 41 is upwardly elevated, for discharging air pres sure present in the tube 52 to the atmosphere as shown in FIG. 7(b).

To avoid descent of the slider 41 by gravity immediately after contact of the angle 43a of the slidable plate 43 with the projection 42 on the slider 41, then tending to move downwardly a braking device is employed to give a frictional resistance to the movement of the slider 41. This braking device comprises a through hole 50 formed in the solid body 39 and having one end opened towards the guide groove 40 and the other end opened towards the atmosphere. A friction piece 49 is loosely inserted in said through hole 50 and is in turn adjustably pressed towards the slider 41 by an adjustment screw 51 tapped into said through hole 50.

As best shown in FIGS. 7(a) and (b), so long as the cylinder rod 10 remains in the retracted position, the passages 46a and 46b do not communicate to each other. Only when the cylinder rod 10 arrives at the extended position, can this communication be established.

The cylinder 7 can be controlled in response to the position of the slider 41 within the: guide groove 40 in such a manner as will be described in the description of a fluid flow control circuit shown in FIG. 14.

The fluid operated fastener feeding apparatus of the present invention further comprises a fastener supply control unit for controlling the operation of the fluid flow control circuit associated with the cylinder 7 in response to the presence of a row of fasteners on the track 5. This fastener supply control unit is shown in FIGS. 1 and 2 and FIGS. 8(a), (b) and (c) and comprises a pair of fluid flow detectors 53, 54 mounted above the track 5 in spaced relation to each other as shown in FIGS. 1 and 2. Because these fluid flow detectors 53, 54 are of the same construction and, though spaced from each other a predetermined distance and are mounted above the track in the same way, only one of, the detectors 53, will be described in detail so far as the mechanical details thereof are concerned with particular reference to FIGS. 8(a), (b) and (c).

The fluid flow detector 53 is formed to represent a substantially inverted J-shape having a space 55 defined by an upright body 57, a suspended body 57a and an overhang 57b. This fluid flow detector 53 is mounted in position with the upright body 57 rigidly secured to a downwardly inclined platform 27 by the use of bolts (not shown) in such a way that the track 5 having a guide 50 overlying the spaced rails 5a and 5b as shown in FIG. 8(0) is substantially situated within the space 55 as shown. The fluid flow detector 53 has an air supply nipple 56 communicating to a blow opening 59 through a passage 58 extending therebetween in the upright body 57. This detector 53 also has an air discharge nipple 63 communicating to an inlet opening 61, formed in the suspended body 57a in alignment with the blow opening 59, through a discharge passage 62 extending between the inlet opening 61 and the discharge nipple 63 through the upright body 57, overhang 57b and the suspended body 57a. Both the blow opening 59 and the inlet opening 61 are open to the space 55 and are so arranged that the imaginary line connecting between these openings 59, 61 extends at a predetermined angle relative to the track 5, i.e., the direction of travel of fasteners in a row on the track 5 as shown in FIG. 8(b) with the blow opening 59 and the inlet opening 61 respectively situated at the upstream and downstream sides of the downwardly inclined track 5.

In the above construction, the air supply nipples 56 of both fluid flow detectors 53, 54 are connected to a fluid source and the air discharge nipples 63 thereof are connected to the fluid flow control circuit, both in such a manner as will be described later with reference to FIG. 14. Each fluid flow detector 53, 54 operates in such a manner that a row of the fasteners guided along the track 5 from the hopper section to the escapement section will interrupt the passage of air from the blow opening 59 to the inlet opening 61, while passage of air from the blow opening 59 to the inlet opening 61 will be permitted when no fasteners on the track 5 are present. It should be also noted that, as long as the passage of air from the blow opening 59 to the inlet opening 61 is interrupted because of the presence of a row of the fasteners on the track 5, air emerging from the blow opening 59 acts, without entering the inlet opening 61, will force the fastener row oriented downwardly oriented along the track 5, because said blow opening 59 is, as hereinbefore described, situated at the upstream side relative to the inlet opening 61.

The details of the escapement assembly 67 are shown in FIGS. 9(a), (b) and (c) and reference thereto will now be made. The escapement assembly 67 has a fastener passage 68 and is connected to the lower end of the track 5 by means of connectors 69 in any known manner with said fastener passage 68 vertically downwardly oriented. A block 70 forming a part of the escapement assembly 67 is formed therein with a cylinder bore 71 extending at right angles to the longitudinal axis of the fastener passage 68 and has a plunger 72 slidably accommodated in said cylinder bore 71.

The escapement assembly 67 includes an escapement plate 73 connected at one end with the plunger 72 by a connecting plate 74 for movement together with said plunger 72. Both ends of the cylinder bore 71 are respectively closed by closure plates 75, 76 and a connecting end 72a of the plunger 71 slidably extends through the closure plate for connection with the connecting plate 74. Another block having the 77 fastener passage 68 formed therein is rigidly secured to the block 70. Also, there is a coupling sleeve 78 having one end connected to a lower open end of the fastener passage 68 and the other end connected to a power operated screw driver 80 through a flexible pipe 79.

This escapement assembly 67 is designed so that the fasteners downwardly guided along the track 5 are successively transferred one at a time through the passage 68 to the screw driver 80 by means of the pipe 79. More specifically, each reciprocal movement of the plunger 72 and, hence, the escapement plate 73 causes one fastener to be transferred from the lower end of the track 5 to the fastener passage 68.

The escapement assemby 67 shown in FIGS. 9(a), (b) and (c) may be of the same type as disclosed in the aforementioned copending patent application.

The screw driver 80 may be of any known construction but is, however, provided with a fluid signal generator 81. The details of the fluid signal generator 81 are shown in FIGS. 10 to 13.

Referring now to FIGS. 10 to 13, the screw driver 80 comprises a substantially Y-shaped pipe 102, a driver (not shown), a motor for driving said driver and other necessary components known to those skilled in the art. The fluid signal generator 81 is fitted to the screw driver 80 on the body 83 by means of a plurality of set screws 82a, 82b. A dog 84 is fixed to a slidable sleeve 83c which sleeve 83c is carried by the body 83 and is normally separated from the body 83 by a compression spring 106. This dog 84 will engage the angled end 103 of a hook 85 as said dog 84 moves toward the hook 85. A container 86 for the fluid signal generator 81, formed with an air intake port 87 communicating with an air passage 89 leading to a small hole 88.

A slidable rod 90 is housed within a bore 93 which will be described later. This rod 90 is formed therein with a diametrically extending hole 91, which may communicate with the small hole 88 depending on the positioning of the rod 90, and also with an exhaust passage 92 axially extending in said spool 90 and having one end communicating with said hole 91 and the other end opened towards the atmosphere through the Y- shaped pipe 102. The rod 90 is slidably accommodated within the bore 93 formed in the container; a pin member 94 extends through a hole 95 formed in the hook 85, a slot 96 formed in the container, and finally a hole 97 formed in the rod 90, whereby the hook 85, the container 86 and the rod 90 are all operatively connected. Guide pieces 98a, 98b press both ends of the hook 85 by means of screws 99a, 99b received in their respective holes 100a, l00b. There are two holes 101a, 10lb through which extend the set screws 82a, 82b used to secure the signal generator 81 to the body 83.

The fluid signal generator 81 of the above construction is designed so as to operate in the following manner.

Assuming that air pressure is applied to the passage 89 in the container 86, this air under pressure flows into the hole 91 of the rod 90, which is then in position with the passage 89, and is discharged to the atmosphere through the exhaust passage 92 by means of the Y-shaped pipe 102. If the Y-shaped pipe 102 is compressed to operate, i.e., when the screw driver is thrust forward towards the Y-shaped pipe 102 to drive a fastener, the dog 84 engages against the angled end 103 of the hook 85 thus moving the hook 85 and establishing the condition shown in FIG. 12(b). At this time, the sliding movement of the hook 85 caused by the engagement of the dog 84 with the bent end 103 is transmitted to the rod 90 through the pin member 94 whereby said rod 90 is also axially moved a distance defined by the length of the slot 96 formed in the container 86.

In the condition shown in FIG. 12(b), communication between the hole 88 and the hole 91 of the rod 90 is interrupted and no air is discharged to the atmosphere through the exhaust passage 92. After the screw has been driven, i.e., after the screw driver has disengaged from the work, the rod 90 returns to its original position, as shown in FIG. 12(a), by the action of a compression spring 104.

It should be noted that, during the condition shown in FIG. 12(a), the air under pressure that hasbeen fed to the exhaust passage 92 through the passage 89 is discharged to the atmosphere through the Y-shaped pipe 102 and, during the condition shown in FIG. 12(b), the pressure in a line leading to the passage 89 increases enough to operate a booster B1 in the fluid circuit as will be described in the subsequent description with reference to FIG. 14.

By repeating each cycle of operation described above, a plurality of fasteners can be successively driven into a workpiece or workpieces (not shown).

There are two sockets 105a, 105!) for holding the compression spring 104 and one the socket 1050 is stationarily held in position by a pin 107.

Referring now to FIG. 14, in which the fluid circuit is shown, the fluid circuit generally comprises a fluid supply circuit A including a source of compressed air, a fluid flow control circuit B for the screw driver 80 and the escapement assembly 67 and a fluid flow control circuit C for the cylinder 7. These circuits A, B and C will be hereinafter described in the order given above. Fluid Supply Circuit A Compressed air from the air source S flows through an air filter F1 to three lines P1, P2 and P3. Air present in the line P1 is supplied in part to the screw driver 80 through a line P41 and in part to the fluid flow control circuit C through an ON-OFF switch SS1 via a line P5. It should be noted that air that has passed through the oiler 01 contains oil for lubricating movable parts of the various mechanical devices including the valves and the screw driver 80. Air present in the line P2 is supplied to the fluid flow control circuit B through a pressure regulator R1 via a line P6.

Air present in the line P3 is supplied through an ON- OFF switch SS2 by means of a pressure regulator R2 to three lines P7, P8 and P9: The line P7 is connected to the nipple 56 of the detector 53, the line P8 to the nipple 56 of the detector 54 and the line P9 to the signal generator 86.

Fluid Flow Control Circuit 8 In FIG. 14, the signal generator 86 in circuit B is schematically illustrated as positioned with the hole 91 of the rod 90 communicated with the passage 88. When the screw driver 80 is thrust forwardly towards the Y- shaped pipe 102 to drive a fastener the compression spring 106 is compressed, thereby interrupting the communication between the passage 88 to the hole 91 of the rod. Upon separation of the passage 88 and the hole 91, pressure in the line P6 increases and, thereafter, because of the pressure differential, the booster B1 becomes activated so as to complete a circuit between the line P5 and a line P10. The line P10 is in turn connected both to a delay valve DV1 and an air tank AT1. The delay valve DV1 at this time receives air pressure from both sides thereof, and a spring force is applied to one side of the delay valve DV1. The delay valve DV1 is constructed so that communication between the line P6 and a line P11 may be interrupted.

After the screw driver 80 has been disengaged from the work and when the slidable portion 83a returns to its original position, the hole 91 is open to the passage 88. At this time, the booster B1 ceases to apply air pressure and, therefore, the supply of air from the line P5 to the line P10 is interrupted. Accordingly, receipt of air pressure by the delay valve DV1 from both sides ceases and air contained in the tank AT1 is supplied to said delay valve DV1; said air from the tank AT1 being sufficient to overcome the spring force ofa spring built into the delay valve DV1 and thereby establish communication between the lines P6 and P11.

It should be noted that, because of the provisions of a check valve CV1, no air from the tank AT1 will flow back to the line P10 and the timing of the delay valve DV1 operation, i.e., the time at which the communication between the lines P6 and P10 is to be established, can be adjusted by adjusting a throttle valve TV1.

Air under pressure that has passed through the delay valve DV1 and has been fed from the line P6 flows into the escapement assembly 67 and subsequently causes a spring 108, operatively housed within the escapement assembly 67, to move the plunger 72. After the air under pressure from the line P11 has completely moved the plunger 72, a portion of said air flows to the pipe 79 through a coupling sleeve 78 (FIGS. 9(a) and (c)) whereby a fastener staying within the pipe 79 transferred from the track 5 can be thrust forwardly towards the Y-shaped pipe 102.

After a predetermined lapse of time, the air in the tank AT1 is exhausted to the atmosphere through the throttle valve TVl via an exhaust port of the booster B1 and, subsequently, the delay valve DV1 is returned to its original position by the action of the built-in spring of said delay valve DV1. At the same time, the supply of air to the pipe 79 is immediately interrupted and, thereafter, the escapement assembly is returned by the action of the spring 108, to the original position as shown in FIG. 14. Air pressure remaining in the line P11 is exhausted through an exhaust port of the delay valve DV1 already returned to the original position.

It should also be noted that the regulator R1 is used to adjust the pressure to be applied to the escapement assembly 67.

One cycle of operation of the flluid flow control circuit B is thus completed and it can be repeated each time the screw driver 80 is disengaged from the work so that another fastener can be thrust towards the Y- shaped pipe 102.

. Fluid Flow control Circuit C Furthermore, a line Pa leading to a booster B2, a line P5b leading to a relay valve RV] and a line P50 leading to a booster B3 are connected to each other at a junction J which is in turn connected to the line P5. Between the booster B2 and the junction J, the line P5a is branched to both the relay valve RVl and an air tank AT2. Similarly between the booster B3 and the junction J, the line P50 is branched to both the relay valve RVl and an air tank AT3.

In the situation shown, since the flow of air from the blow opening 59 to the inlet opening 61 of the detector 54 is interrupted by the presence of the fastener row 109, no pressure is present in a line P13 connecting the nipple 63 of the detector 54 and the booster B2. Similarly, since flow of air from the blow opening 59 to the inlet opening 61 of the detector 53 is interrupted by the presence of the fastener row 109, no pressure is present in a line P12 connecting between the nipple 63 of the detector 53 and the booster B3.

Accordingly, air flowing into the booster B2 from the line P5a is, because there is no pressure present in the line P13, exhausted to the atmosphere through an air exhaust port EXHl of said booster B2. On the other hand, air flowing into the booster B3 through a line P14 via an intake port positioned between exhaust ports EXH2 and EXH3 is exhausted to the atmosphere through the exhaust port EXH2 because no pressure is present in the line P12. Air under pressure flowing in the line P5c towards a spool valve BS1 of said booster B3 acts on said spool valve BS1 so as to close an opening into the exhaust port EXH3 and thereby cause this air to flow to the relay valve RVl.

The relay valve RVl then receives air from the line P5a and air from the line P5c, and because there is a spring on the side adjacent the booster B3 which acts to prohibit change in the position of said relay valve RVl at this time, the relay valve RVl is held in such a position so as to interrupt communication between the lines P5b and P15.

Assume that some of the fasteners guided along the track 5 in a row have been consumed and that the last one of the fasteners in the row has passed behind the detector 53; passage of air from the blow opening 59 to the intake opening 61 of the detector 53 is established. The air then flows from the line P7 into the line P12 through the detector 53 and, as a result, the ehxaust port EXH2 of the booster B3 closes. As the exhaust port EXH2 is thus closed, the air pressure that has fed to said booster B3 through the line P14 overcomes the resilient force of the spring connected to the spool valve BS1 as hereinbefore described. The exhaust port EXH3 is then opened so that air flowing into the booster B3 through the line PSC will be exhausted to the atmopshere through said exhaust port EXH3. At this time, the booster B2 remains inoperative. In other words, establishment of communication between the lines P7 and P12 through the detector 53 does not bring about any change in the air flowing into the relay valve RVl through the line P5a, but this causes the air in the line P5c to be discharged through the exhaust port EXH3 of the booster B3. Further the relay valve RVl is, by the action of a spring, still held in position to interrupt communication between the lines P5b, P15. Therefore, no operation of the cylinder 7 takes place at this time.

If the number of fasteners decreases and the row of the remaining fasteners extends below the level of the detector 54 to the escapement assembly, passage of air from the blow opening 59 to the inlet opening 61 ofthe detector 54 can be subsequently established, thus communicating the line P8 with the line P13.

If this condition is established while the detector 53 is in position to communicate, the line P7 to the line P12, the exhaust port EXHl of the booster B2 closes because of the air pressure in the line P13. Then, air flowing into the booster B2 through the line P5a will no longer flow thereinto, but will flow solely into the relay valve RVl, and the pressure of said air flows into booster B2 becomes sufficient to overcome the resilient force of the spring acting on the relay valve RVl and thereby bring the relay valve RVl into a position whereby communication between the lines P5b and P15 is established.

Air flowing through the relay valve RVl flows in part to a relay valve RV2 through a line P17 and in part to a relay valve RV3 through a line P15a and also to the tube 52 connected to the fluid controller 13. The relay valve RV2 is normally held in position to communicate the line P17 to a line P20 leading to a chamber of the cylinder 7 whereby the cylinder rod 10 is brought to the retracted position.

So long as the cylinder rod 10 is in the retracted position, air flowing in the line P16 is not discharged to the atmosphere since the passages 46a, 46b of the fluid controller 13 are not at this time aligned with each other through the passage 48 formed in the slider 41 of said fluid controller 13. Therefore, air under pressure flowing through the line P16 flows into a line Pl5b and then to the relay valve RV3 where it acts against a spring of said valve RV3. As the pressure in the line PlSb increases enough to overcome the resilient force of the spring of the relay valve RV3, said spring is brought into the contracted position. At the same time, air thus fed to the line P18 flows into the relay valve RV2 and acts thereon against a spring of said relay valve RV2 whereby said relay valve RV2 is brought into position to interrupt the communication between the lines P17 and P2 0 and to establish communication between the line P20 to the atmosphere through an exhaust port EXH4 of said relay valve RV2. Therefore, air contained in the chamber 7a of the cylinder 7 when the cylinder rod 10 is in the retracted position can be exhausted to the atmosphere through the relay valve RV2 as said cylinder rod 10 moves towards the extended position.

As the cylinder rod 10 approaches the extended position, the cylinder block 11 causes the slider 41 to elevate in the manner as hereinbefore described, so that the passages 46a, 46b formed in the body 39 of the fluid controlled 13 are communicated to each other through the passage 48 formed in the slider 41. Upon this communication, air present in the lines P15, PlSa, P15b and P16 is discharged to the atmosphere through the fluid controller 13 and the relay valves RV2, RV3 are restored to their original positions. Upon return of the relay valve RV2 to the original position, communication between the lines P17, P20 is again established, and air flowing under pressure through the relay valve RVl is supplied to the chamber 7a of the cylinder 7, thus causing the cylinder rod 7 to move to the retracted position.

During the movement ofthe cylinder rod 10 from the extended position to the retracted position air contained in the chamber 7b of the cylinder 7 can be discharged to the atmosphere through an exhaust port EXHS of the relay valve RV3 and, upon return of the cylinder rod 10 to the retracted position, the slider 41 is downwardly moved by the cylinder block 11 to interrupt the communication between the passages 46a, 46b of the fluid controller 13, thus completing one reciprocal movement of the cylinder rod 10, that is, one operation of the cylinder 7. As hereinbefore described, each operation of the cylinder 7 causes the rotary drum 4 to rotate about the shaft 19 to upwardly scoop fasteners from the bottom of the fastener receiving funnel 2 and then to supply them onto the track 5.

This operation of the cylinder 7 is repeated until the fasteners thus supplied onto the track are arranged thereon in a row of length sufficient to interrupt passage of air from the blow opening 59 to the inlet opening 61 of both of the fluid flow detectors 53, 54.

In the circuit C, a throttle valve TV2 disposed on the line P50 and the air tank AT2 cooperate with each other to control the time period between the time when the passage of air from the blow opening 59 to the inlet opening 61 of the detector 54 is established and the time when the cylinder 7 is consequently operated. Further, a throttle valve TV3 and the air tank AT3 cooperate to each other to control the time period between the time when the passage of air from the blow opening 59 to the inlet opening 61 of both of the detectors 53, 54 is interrupted and the time when the cylinder 7 is consequently brought to the inoperative position. A throttle valve TV4 disposed on the line P16 is used to control the amount of air fed to the fluid controller 13 and the relay valve RV3, and a throttle valve TV5 disposed on the line P20 is used to control the speed of movement of the cylinder rod from the extended position to the retracted position. Connected in parallel with to this throttle valve TVS, a check valve CV2 is provided to prevent the backflow of air. A throttle valve TV6 disposed on the line P19 is used to control the speed of movement of the cylinder rod 10 from the retracted position to the extended position. Connected in parallel with this throttle valve TV6, a check valve CV3 is provided to prevent the backflow of air.

In the arrangement of the fastener feeding apparatus as hereinbefore fully described, assuming that a row of fasteners is present on the track 5 and both of the detectors 53., 54 are in position to interrupt communication between the lines P7 and P12 and between the lines P8 and P13, respectively, the fasteners can be successively and individually fed to the slidable portion 83a of the screw driver through the flexible pipe 79. When the screw driver 80 is thrust forward towards the Y-shaped pipe and a lever 110 is subsequently depressed, the spring 106 is compressed and the driver 1111 is rotated to drive the fastener. After the fastener has been driven and the screw driver 80 is disengaged from the work, the spring 106 returns when the original position and a fluid signal is fed by the signal generator 81 to the escapement assemby 67 so that the escapement plate 73 can be reciprocated to feed a subsequent fastener into the passage 68 and then to the tube 79.

As this operation of the screw driver 80 is repeated, the fasteners on the track 5 in a row are successively consumed until, finally, the passage of air from the blow opening 59 to the inlet opening 61 of both of the detectors 53, 54 is permitted and, in the manner as hereinbefore described with reference to FIG. 14, the

rotary drum 4 is rotated to supply fasteners from the bottom of the fastener receiving funnel 2 the track 5. Operation of the cylinder 7 ceases when a sufficient number of fasteners are placed on the track 5 to interrupt the air flow through the detectors 53, 54 and communication between the lines P7 and P12 and between the lines P8 and P13 is interrupted.

The fastener feeding apparatus constructed in accordance with the present invention has many advantages. One of these advantages is that, since all the components of the fastener feeding apparatus are fluidoperated, the maintenance costs can be reduced along with substantial improvement in performance when compared with a fastener feeding apparatus of the same kind employing both electrical power and a fluid source. In fact, in the apparatus of the present invention, no electrical contacts, which are liable to damage, are employed, so reliability is assured in this operation. The fact that no electrical power is employed facilitates employment of light and inexpensive material, such as synthetic resins, for most parts of the apparatus, which ultimately results in reduction of the manufacturing cost and simplification of the apparatus itself.

Another advantage resides in the arrangement of each of the fluid flow detectors 53, 54 wherein the blow opening 59 and the inlet opening 61 are disposed so that air flowing from the blow opening 59 towards the inlet opening 61 is directed onto the row of fasteners on the track 5 to facilitate downward movement of the fasteners towards the escapement assembly. In other words, each of the detectors 53 and 54 functions not only to detect the absence or presence of the row of the fasteners on the track 5, but also to facilitate the down ward transfer of each of the fasteners along the track 5.

Furthermore, since the rotary drum is designed to be rotated by the fluid operated cylinder using the motion translator for translating linear motion into rotary mo tion, no substantial noise is generated and the cost of manufacturing the apparatus itself is also less when compared with the conventional apparatus employing an electrically operated motor for rotating the rotary drum.

Although the present invention has been fully described by way of example with reference to the accompanying drawings, it should be noted that various changes and modifications are apparent to those skilled in the art. Therefore, such changes and modifications should be construed as included within the true scope of the present invention unless they depart therefrom.

What we claim is:

I. In combination, a fluid-operated fastener feeding apparatus and a power operated fastening tool, said combination comprising a hopper adapted to contain therein a number of fasteners, a rotary drum rotatably mounted onto said apparatus and forming one side of said hopper, a fluid-operated drive mechanism for rotating said rotary drum, a track downwardly extending from said hopper for downwardly guiding a row of fasteners that has been supplied onto said track from the bottom of said hopper by said rotary drum, an escape ment mounted on said track for successively separating the downwardly guided fasteners one at a time and feeding each fastener to said fastening tool, fluidoperated detection means located along said downward sloping track for detecting the presence and absence of fasteners on said track, a fluid signal generator attached to said fastening tool for generating a fluid signal whereby the feeding of fasteners from said escapement assembly to said fastening tool is regulated, and a fluid control circuit to which is connected a fluid source for providing fluid power to operate said fastening tool, said fluid generator, and said escapement mechanism, for providing power to control said escapement mechanism by providing the fluid for the fluid signal generated by said fluid signal generator directed to said escapement mechanism, and further providing a source of fluid power to operate said fluid-operated drive mechanism in response to a fluid signal from said fluid-operated detection means, fluid for the signal generated by said fluid-operated detection means also being provided by said fluid source.

2. A combination as claimed in claim 1, wherein said fluid-operated drive mechanism comprises a geared wheel mounted on said rotary drum in coaxial relation therewith;

a piston-cylinder drive means having a piston rod movable between extended and retracted positions;

translating means for translating linear motion into rotary motion, said translating means connected between said piston rod and said geared wheel whereby reciprocal movement of said piston rod causes said rotary drum to rotate in one direction; and

a drive signal generating means operatively positioned adjacent to said piston rod for generating a fluid signal in response to the movement of said piston rod toward its extended position, the fluid drive signal generated by said drive signal generating means being directed to the piston-cylinder drive means whereby the piston rod in the piston cylinder drive means is directed to retract toward the retracted position upon reaching its fully extended position.

3. A combination as claimed in claim 1, wherein said fluid-operated detection means comprises at least one fluid flow detector having a first fluid passage connected to the fluid source and situated on one side of said downward-sloping track, and a second fluid passage positioned on the opposite side of said track, said second passage being connected to the fluid control circuit and aligned with said first passage to receive fluid flowing from said first passage whereby said fluid detector generates a fluid signal when the flow of fluid from said first passage to said second passage is established due to the absence of the row of the fasteners on said track.

4. A combination as claimed in claim 3, wherein said first fluid passage is arranged at the upstream side with respect to the track and said second fluid passage is located at the downstream side with respect to the track, whereby t he fasteners on the track are forced to move downwardly along the track by the fluid flowing between said fluid passages.

5. A combination as claimed in claim 1, wherein said escapement assembly comprises a solid body having a cylinder bore and a passage therein, said passage being connected to said fastening tool by means of a flexible tube;

a fluid-movable plunger slidably housed within said bore;

an escapement plate connected with said plunger and movable back and forth in direct relation to the back and forth movement of said plunger, said escapement plate operating to transfer individually the fasteners in the row on the track to said passage;

and shutter means for selectively closing and opening said passage, said shutter means having an opening for feeding into said flexible tube the fluid under pressure used for operating said plunger, thereby thrusting the fastener in said flexible tube onto the fastening tool.

6. An apparatus as claimed in claim 1, wherein said fastening tool comprises a fastening body;

a fluid signal generator, said fluid signal generator comprised of a generator body rigidly secured to said fastening body, said generator body having therein a cylinder bore and a first fluid passage, said first fluid passage being open to said cylinder bore at one end and open to the fluid source at the other end; an axially slidable rod mounted within said cylinder bore, said slidable rod having a second fluid passage running therethrough, said second fluid passage being open to an exhaust at one end and at the other end selectively open and closed to the cylinder bore opening of said first fluid passage in response to the sliding movement of said slidable rod; and a slidable hook plate situated above said axially slidable rod and connected thereto, said hook plate having both ends formed with angled members; and

a slidable member telescopically and movably on said fastening body, said slidable member having a dog for engaging with the angle members of said hook plate and thereby moving said hook plate.

7. A combination as claimed in claim 1, wherein said fluid control circuit includes:

a fluid supply circuit for controlling the supply of fluid in the entire system from the fluid source; an escapement assembly circuit connected to said fluid supply circuit for controlling the operation of the escapement assembly in response to the fluid signal from said fluid signal generating device located on the fastening tool, said escapement assembly circuit having a delay valve forming a pilot circuit when the fluid signal generating device is supplied with fluid under pressure;

a fastener transfer instruction circuit connected to said supply circuit for controlling the time necessary for rotating said rotary drum by the fluidoperated drive mechanism to replenish the fasteners to the track from the hopper in' response to a fluid signal from said fluid-operated detection means, said fastener transfer instruction circuit having a relay valve means and fluid tank means, said fluid tank means located between said relay valve means and said fluid-operated detection means, for controlling the length of time of operation of said fluid-operated drive mechanism; and nd a rotary drum drive circuit connected to said fastener transfer instruction circuit for producing the driving motion of said fluid-operated drive mechanism rotating said rotary drum in response to a fluid sig nal from said fastener transfer instruction circuit.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3265273 *May 11, 1964Aug 9, 1966Index Card Company LtdMachine for feeding and setting fasteners
US3305155 *Mar 25, 1965Feb 21, 1967Willis Clyde PEscapement mechanism
US3583451 *Apr 9, 1969Jun 8, 1971Dixon Automatic ToolMachine for automatically driving threaded fasteners
US3642039 *Jun 2, 1969Feb 15, 1972Hill Rockford CoPower screwdriver
US3779422 *Jul 18, 1972Dec 18, 1973Matsushita Electric Ind Co LtdFastener feeding apparatus
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4010944 *Jun 16, 1975Mar 8, 1977Koppers Company, Inc.Blank feeding device having an adjustable and automatic positioning backstop means
US5400838 *Jan 14, 1994Mar 28, 1995Gas Research InstituteAutomatic packaging method and apparatus
Classifications
U.S. Classification81/430, 81/433, 221/9, 227/116
International ClassificationB25B23/04, B25B23/02
Cooperative ClassificationB25B23/04
European ClassificationB25B23/04