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Publication numberUS3446168 A
Publication typeGrant
Publication dateMay 27, 1969
Filing dateMar 10, 1967
Priority dateMar 10, 1967
Publication numberUS 3446168 A, US 3446168A, US-A-3446168, US3446168 A, US3446168A
InventorsGordon Mason L
Original AssigneeAblestik Adhesive Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Tube-folding arrangement
US 3446168 A
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Description  (OCR text may contain errors)

May 27, 1969 GORDON TUBE FOLDING ARRANGEMENT Sheet Filed March 10, 1967 ACCUM;

2 II II U INVENTOR MASON L. GORDON ATTORNEYS RESERVOIR EIG.4

y 7, 1969 M. L. GORDON 3,446,168

TUBE -FOLDING ARRANG EMENT Filed March 10, 1967 Sheet 43 of 2 INVENTOR v MASON GORDON ATTORMYS United States Patent US. Cl. 113-54 14 Claims ABSTRACT OF THE DISCLOSURE The open end of a metal foil tube is inserted between plates having a tapered entrance leading to opposed surfaces, which are brought toward each other to compress the tube end. The tube then is removed and the compressed end is pushed laterally and bent over, after which it again is introduced between the plates and compressed a second time. The cycle of bending over and flattening the tube end is repeated to create a multiple fold.

BACKGROUND OF THE INVENTION The field of the invention The invention relates to the folding of the ends of metal foil tubes to form a closure.

The prior art In being prepared for consumer use, metal foil tubes are filled with the cap end closed, while the opposite end is open and accepts the contents. It is necessary then to fold the open end to form a closure to seal in the contents. Multiple folding of the tube end will form an adequate seal, retaining the material within the tube. Conventionally, this has been done by engaging the end of each tube individually with a means that grips the end of the tube and effects the folds to seal the tube.

SUMMARY OF THE INVENTION According to the present invention, an arrangement is provided for automatically and simultaneously folding the ends of a multiplicity of tubes, rather than folding the tube ends one at a time. The result is a great saving of time and expense along with a substantially increased production rate.

The invention includes a tray adapted to receive a substantial quantity of filled tubes with the tip ends down. The tubes are spaced in aligned rows, and above each row is a pair of jaws having opposed parallel flat surfaces. Initially the jaws are separated so that there is a gap between having a tapered entrance resulting from chamfered lower edges of the jaws. The tray is raised so that the tubes are brought between the opposed jaws, with the tube ends being partially compressed as they are moved through the tapered entrances. Then, the jaws are moved to squeeze the tube ends flat, after which the tray is lowered and a horizontal plate moves across the ends of the tubes. This knocks over the flattened ends of all of the tubes. Next, the tray again is raised to position the doubled-over ends between the jaws, and the flattening operation is repeated. After successive steps by the horizontal plate and the compressings jaws, a multiple fold is accomplished and the closure is completed.

An object of this invention is to provide an improved means for forming a closure for metal foil tubes.

Another object of this invention is to provide an arrangement for folding the ends of a plurality of tubes simultaneously.

An additional object of this invention is to provide a means for increasing the speed and reducing the cost for folding the ends of a quantity of metal foil tubes.

3,446,168 Patented May 27, 1969 These and other objects will become apparent from the following detailed description taken in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a perspective view of a typical tube to be folded in accordance with this invention;

FIGURE 2 is a transverse sectional view, partially in elevation, illustrating the components of the device for accomplishing the folding of the tube end;

FIGURE 3 is a fragmentary perspective view illustrating the jaw portion of the tube-folding machine;

FIGURE 4 is a schematic view illustrating the successive steps in forming the folded end of the tube; and

FIGURE 5 is a schematic diagram of the circuit for actuating the tube-folding machine.

DESCRIPTION OF THE PREFERRED EMBODIMENT The arrangement of this invention is adapted to form a closure for conventional metal foil tubes, such as the tube 10 shown in FIGURE 1. The tube 10 has a tapered end 11 closed by a removable cap 12. As manufactured, the tube 10 has a cylindrical side wall 13 extending to an open end 14 through which the contents are admitted when the tube is filled. For the tube 10 shown in FIG- URE 1, a material 15 has been introduced into the tube to a level below the open end 14. It is necessary at this point to form a closure at the open end 14 so that the tube 10 is sealed and ready for the consumer.

In order to accomplish such a closure, a quantity of the tubes 10 is placed into a tray 17 having a base 18 supported on the horizontal surface 19 of a frame 20. The tray 17 includes a plurality of vertical openings 21, which are dimensioned to substantially complementarily receive the tip ends of the tubes 10. The tapered portions 11 of the tubes 10 rest upon corresponding surfaces in the apertures 21, so that all the open ends 14 of the tubes extend above the tray 17 an equal distance. The openings 21 are arranged in the tray 17 so that the tubes 10 are positioned in straight parallel rows, with their longitudinal axes in a vertical attitude. There are four rows of the tubes 10 shown in the embodiment of FIGURE 2, but the machine may be constructed to accommodate other and larger numbers of rows as desired.

The frame 20 includes a vertical portion 23 at the upper end of which is a horizontal section 24 parallel to the surface 19 of the base 20. The horizontal frame member 24 carries a horizontal jaw plate 25. Depending from the latter member are jaws 26, which may be milled from the same material that forms the plate 25.

The jaws 26 are in the form of elongated ribs extending in a vertical direction. Each jaw includes a chamfered bottom end surface 27, inclining upwardly and to the right as the device is shown in FIGURE 2. With the machine constructed to operate on four rows of tubes 10 in the tray 17, there are four of the jaws 26 provided. The connection between the jaws 26 and the horizontal plate 25, which, in turn, is secured to the upper frame element 24, means that the jaws 26 are fixed.

Opposed to the jaws 26 are movable jaws 28. These are similar in configuration to the jaws 26, being again elongated vertical elements having chamfered bottom edges 29. As shown in FIGURE 2, the edges 29 incline upwardly and to the left. Consequently, the inclined surfaces 27 and 29 of the jaws 26 and 28 provide a tapered entrance 30 to a narrower gap 31 between the opposed parallel flat faces of the jaws 26 and 28. The entrances 30 and gaps 31 are positioned directly above the rows of openings 21 in the tray 17, and hence are vertically aligned With the tubes 10 when positioned in the tray 17.

The jaws 28 are arranged to be shifted horizontally in a straight line toward the fixed jaws 26 in a direction normal to the jaw faces. This may be accomplished, as shown in FIGURES 2 and 3, by connecting each of the jaws 28 to a rod 33 extending from a power cylinder 34. The rod 33 extends through the vertical frame element 23 and slidably passes through an opening formed in each of the fixed jaws 26. The rod 33 is secured suitably to each of the jaws 28 so that the four jaws 28 will move with the rod. Consequently, when the power cylinder 34 is actuated, the rod 33 is moved to the left from the position shown in FIGURES 2 and 3, shifting the jaws 28 with it so that they approach the jaws 26 and reduce the width of the gaps 31. When the cylinder 34 is retracted, the backs of the jaws 28 are brought to bear against the backs of the fixed jaws 26 in the adjacent rows. This provides a stop that determines the width of the gaps 31, which are narrower than the diameter of the tubes 10.

An additional horizontal power cylinder 36 is included, the piston rod of which is parallel to the cylinder 34 and conects to a horizontal metal plate 37 that extends through the vertical frame element 23. A sheet 38 of resilient material, such as an elastomer, may be included on the lower surface of the plate 37, but for folding most tubes it is unnecessary and may be omitted. Alternative to using a resilient material, the sheet 38 may be made advantageously of Teflon, which facilitates the movement of the horizontal plate 37 across the ends of the tubes during operation of the machine. The undersurface of the plate 37 is positioned below the upper ends 14 of the tubes that are disposed in the tray 17. The direction of movement of the horizontal plate 37 is parallel to that of the jaws 28, and so is perpendicular to the faces of the jaws.

A third power cylinder 39 is positioned vertically beneath the frame and includes a rod 40 that extends to the base 18 beneath the tray 17. Extension of the rod 40, therefore, will move the tray 17 and its contents vertically upwardly toward the jaws.

The sequence of operation of the tube-folding arrangement of this invention may be seen by reference to FIG- URE 4, where the various stages of operation are shown sequentially. After the tray 17 has received the tubes 10 which previously have been charged with the material 15 they are to retain, the power cylinder 39 is actuated. The rod 40, therefore, shifts the tray 17 upwardly from the position of step A to the position of step B. A suitable means is provided for limiting the upward movement of the tray 17, such as the stop 42 to be engaged by a projecting stop element 43 connected to the tray 17. As the tray 17 moves upwardly, the open upper ends 14 of the tubes 10 pass through the entrances 30 into the gaps 31 between the jaws 26 and 28. As the ends of the tubes move through the tapered entrance portions 30, they become compressed slightly to fit in the gaps 31 which are narrower than the tubes.

After the tray 17 has been raised to position B, the cylinder 34 is actuated to shift the jaws 28 toward the jaws 26, as shown at position C. This narrows the gaps 31 so that the upper ends of the tubes becomes flattened between the jaws. The movable jaws 28 force the tube ends tightly together as the jaws are shifted through their stroke by the cylinder 34. All the tubes becomes flattened simultaneously as the four jaws 28 are moved together.

Next, as shown in position D, the jaws 28 are retracted away from the opposing jaws 26, freeing the ends of the tubes, which then are moved downwardly as the tray 17 is shifted in that direction by the cylinder 39.

After that, as indicated for step E, the cylinder 36 moves the horizontal plate 37 inwardly, or to the left as shown, across the flattened ends of the tubes. The tray is positioned vertically at this time by the stop 41 so that the leading edge 44 of the horizontal plate engages each flattened tube end and exerts a transverse force adjacent the juncture 45 between the flattened end and the adjacent part of the tube. This causes all the flattened tube ends 4 to be bent over through approximately a angle about the line of the juncture 45 at the base of the flattened part, where the metal offers little resistance to the bending movement. The flattened part is relatively stiff, and so has little tendency to bend in response to the sideward push of the plate 37.

When the resilient pad 38 is included on the bottom of the plate 37, the step F may be included, in which the tray 17 is raised upwardly slightly after the ends have been bent by the horizontal plate. A stop 46 limits the upward travel of the tray. This additional movement of the tray causes the resilient pad 38 to bend the ends of the tubes over at an angle greater than 90, as the central portions of the tubes become embedded in the resilient pad. This is to facilitate entry of the tube ends into the gaps 31 on the next step shown at G.

In the step G, after the plate 37 has been retracted, the tray 17 again is raised. This forces the flattened bentover end portions of the tubes and the adjacent parts of the bodies of the tubes through the entrances 30 into the gaps 31. As the flattened portions of the tube ends pass through the entrances 30, the inclined jaw surfaces 27 bend them down further. The result is a doubledover part at the end of the tube, as the previously compressed portions are directed downwardly alongside the other portion inserted into the gap 31.

When the tray 17 is raised in step G, it engages a stop 47 which is slightly above the stop 42 contacted by the tray on the previous vertical stroke of step B. Consequently, the tubes 10 are inserted a little farther into the gaps 31, with the bottom edges 48 of the doubled-over flattened portions being above the chamfered lower edges 27 and 29 of the jaws 26 and 28.

Step H follows, which is similar to step C described above. Here, the jaws 28 are moved toward the jaws 26 to tightly compress the doubled-over end part of the tube. After this, as shown at step I, the tray 17 is lowered, and the horizontal plate 37 moved inwardly to again bend over the compressed ends of the tubes. The tray 17 is moved against a stop 49 for the step I, locating it slightly above its original retracted location, seen in positions A, D and E. This is necessary because the tubes now have become shorter as a result of their ends having been doubled over. This locates the leading edge 44 of the horizontal plate 37 adjacent the junctures 50 between the newly compressed doubled-over tube ends and the remainder of the tubes.

The previous slightly higher travel of the tray 17 to the position of step G means that the end edge surfaces 48 of the initially flattened sections are slightly above the juncture lines 50. Consequently, the plate 37 easily pushes over the tube ends, and does not have to attempt to effect a bend at flattened areas where the tubes are more rigid.

In step I, the tray is raised slightly higher than the position of step I when the resilient pad 38 is included, to cause the ends of the tube to be bent to an angle of more than 90. Stop 51 limits the travel for the step J. This step, like the step F, is not included where the tubes do not require being bent this added amount to be certain they will be bent down further to a doubled-over position when inserted between the jaws.

The next step, K, is similar to step G but introduces the bent-over ends and still an additional portion of the tubes into the gaps 31. The vertical stroke for step K is greater than either for step C or for step G as the tray 17 this time contacts a stop 52 to limit its travel. The purpose again is to assure that the subsequent bending of the free tube ends does not encounter previously flattened reatively rigid tube sections. This is to allow the next bends to be made easily and cleanly, and so that they will not later open up.

This is followed by the step L, where the jaws 28 are moved toward the jaws 26, compressing the tube ends. Then, the tray 17 is retracted to the position shown at M, which completes the folding operation.

In this manner, all the tubes positioned in the tray 17 simultaneously are acted upon in each of the steps of the device. Each tube receives a triple fold which completely seals the open end and retains the contents within the tube. One cycle of the machine, therefore, quickly and effectively seals a large number of tubes, avoiding the need to fold the tubes individually.

The components of the tube-folding machine of this invention may be actuated in various ways for mechanical, pneumatic or hydraulic operation. A system based upon hydraulic actuation is illustrated in FIGURE 5, where a reservoir 54 retains the hydraulic fluid pressured by pump 55, which connects through check valve 56 to an accumulator 57. A line 58 from the accumulator includes a shutoff valve 59 and a pressure regulator 60 leading to a four-way control valve 61. The latter valve, when positioned as shown, through the line 62 interconnects the cylinder 34 with the source of pressurized fluid for moving the piston to actuate the jaws 28 in the compressing of tubes received in the gaps 31. At the same time, the valve connects the return line 63 from the cylinder 34 t0 the reservoir 54. Repositioning of the valve 61 causes reverse movement of the power cylinder 34.

The pressurized fluid also connects through a line 65 having a shutoff valve 66 to a four-way control valve 67 having connections 68 and 69 to the cylinder 36 that operates the horizontal plate 37. By positioning the valve 67 as shown, one side of the piston in the cylinder 36 is pressurized, while the other side connects to the reservoir. When the valve position is changed, reverse movement of the piston in the cylinder 36 is obtained to retract the plate 37.

The cylinder 39 for raising the tray 17 that contains the tubes also is connected to the source of pressurized fluid. This is accomplished by a line 71 having a valve 72 from which it extends to four-way control valve 73.'Connections 74 and 75 extend from the valve 73 to the 0pposite ends of the cylinder 39. The line 76 provides a return to the reservoir 54. Thus, the valve 73, appropriately manipulated, pressurizes one end or the other of the cylinder 39 to raise or lower the tray 17.

Of course, suitable automatic controls normally are included with the valves 61, 67 and 73 to accomplish automatic cycling of the machine to fold the ends of the tubes rapidly and without attention.

The foregoing detailed description is to be clearly understood as given by way of illustration and example only, the spirit and scope of this invention being limited solely by the appended claims.

I claim:

1. A device for folding the end of a metal foil tube to provide a closure therefor comprising:

a pair of jaws adapted to receive the end of a metal foil tube,

means for moving a tube to a position between said aws,

means for moving said jaws relatively toward each other for compressing the end of such a tube,

means for subsequently moving said jaws relatively away from each other for releasing said compressed end and leaving the same unsupported, and

means for pushing laterally on said compressed end of said tube for bending over said compressed end and permitting said tube to be again compressed by said jaws and to be again bent over at the end for providing a multiple fold in the end of said tube.

2. A device as recited in claim 1 in which said means for pushing laterally on said compressed end of said tube comprises a member movable transversely in a direction normal to said jaws for engaging the side of the compressed end portion of said tube to effect a bend at the base of said compressed portion by exerting a lateral force on said compressed portion.

3. A device for folding the end of a metal foil tube to provide a closure therefor comprising:

a pair of jaws defining a gap adapted to receive the end of a tube to be folded, tube-positioning means,

said tube-positioning means including means for positioning the end of such a tube in said gap, means for moving said jaws relatively toward each other for flattening said end of said tube therebetween,

said tube-positioning means including means for removing said tube from said jaws after said end has been so flattened, and a member movable in a direction normal to said flattened end for engaging and bending over said flattened end for permitting said tube to be positioned again in said gap and flattened by said jaws, and

to be engaged again by said member for producing a multiple fold in said end of said tube.

4. A device for folding the end of a metal foil tube to provide a closure therefor comprising:

a tube-positioning means,

a pair of jaws,

said jaws having opposed substantially flat surfaces defining a gap therebetween,

said tube-positioning means including means for positioning a tube end in said gap between said aws,

means for moving said jaws relatively toward each other for compressing said end of said tube,

said tube-positioning means including means for subsequently removing said tube end from said jaws, and a member adjacent said jaws movable in a direction normal to said surfaces of said jaws for engaging the compressed end of a tube so removed from said jaws and exerting a lateral force thereon for bending said compressed end transversely relative to said tube where said compressed end connects to the remaining portions of said tube,

whereby upon successive positioning by said tubepositioning means, compression by said jaws and bending by said member a multiple fold is accomplished at the end of said tube to produce a closure for said tube.

5. A device for folding the ends of a plurality of openended metal foil tubes for comprising closures therefor comprising:

tube-holding means for holding a plurality of tubes in an aligned row with the open ends thereof extending outwardly,

a pair of jaws adjacent said tube-holding means,

said jaws having opposed parallel substantially flat surfaces defining a gap therebetween aligned with said row of said tubes,

means for moving said tube-holding means to introduce said ends of said tubes into said gap,

means for moving said jaws relatively toward each other to simultaneously compress the ends of said tubes between said surfaces of said jaws,

means for moving said tube-holding means away from said jaws subsequent to said compression of said tube ends and locating said row of tubes in a predetermined position, and

a member movable laterally relative to said tubes in a direction normal to said surfaces of said jaws for engaging said compressed ends of said tubes adjacent the bases of said compressed ends for pushing on said compressed ends of said tubes and effecting a bend about the bases of said compressed ends,

said tube-holding means, jaws and member being operable successively to effect additional bends in said ends of said tubes for accomplishing multiple folds thereof.

6. A device as recited in claim 5 in which said jaws have an entrance portion adjacent said tube-holding means,

said entrance portion connecting to said gap and tapering from a wider outer portion to a narrower inner portion at said gap for directing said tube ends into said gap,

whereby when said tubes are moved through said entrance into said gap said tube ends experience a limited amount of compression thereof. 7. A device for bending the ends of a plurality of metal foil tubes to provide closure therefor comprising:

a tray,

said tray having spaced parallel rows of aligned apertures therein, said apertures being dimensioned to receive the tip ends of filled tubes, and

being vertically aligned so that said apertures in said tray position such tubes in aligned rows with their open ends extending upwardly, a pair of jaws above each of said rows,

each of said pairs including a first fixed plate and a second movable plate,

said movable plates being movable between a retracted position remote from said fixed plates and an extended position adjacent said fixed plates, said plates having opposed substantially parallel flat surfaces defining an elongated gap substantially vertically aligned with a row of tubes therebeneath, said plates having chamfered bottom edges to provide an upwardly tapered entrance to said gap, said gaps when said movable plates are in said retracted positions being narrower than the diameters of said apertures in said tray for thereby providing gaps narrower than the diameters of the tubes held by said tray, tray-moving means,

said tray-moving means including means for moving said tray upwardly for forcing the open upper ends of the tubes thereon through said entrances and into said gaps, whereby said ends are partially compressed upon being introduced into said gaps, means for moving said movable jaw plates to said extended positions for flattening the ends of said tubes so introduced into said gaps, and

subsequently withdrawing said movable jaw plates to said retracted positions for releasing said ends of said tubes, said tray-moving means including means for lowering said tray for removing said tubes with their ends so flattened from said gaps, a bending plate having a horizontal undersurface,

said tubes when so lowered by said tray-moving means being adjacent said bending plate, and means for moving said bending plate horizontally in a direction normal to said surfaces of said jaws for thereby engaging the sides of said flattened end portions of said tubes and pushing on the same to bend said ends of said tubes through a substantially 90 are along the lines of connection between said flattened ends of said tubes and the remaining portions thereof,

said tray-moving means, jaw-moving means and bending plate-moving means being movable successively for further operating on the ends of said tubes and accomplishing a multiple fold thereof. 8. A device as recited in claim 7 including: a resilient sheet on said undersurface of said bending plate, and in which said tray-moving means includes means for moving said tray upwardly following said bending of said ends by said bending plate for forcing the ends of said tubes against said sheet to become embedded therein and increase the arc of bend of said flattened ends.

9. A device as recited in claim 7 including in addition a sheet of Teflon on said horizontal surface of said bending plate for facilitating said movement of said bending plate upon said engagement thereof with said tubes.

10. A device as recited in claim 7 in which:

said tray-moving means includes means for moving said tray a second time following said bend of said tube ends by said bending plate,

said jaw-moving means includes means for moving said movable jaw plates toward said fixed jaw plates a second time when said tube ends are so positioned in said gaps the second time,

said tray-moving means includes means for positioning said tray such that said tube ends when flattened by said jaws upon said second movement of said jaws are adjacent said bending plate, said bending plate-moving means includes means for moving said bending plate transversely a second time for pushing over the ends of said tubes a second time to eflect a substantially bend thereof substantially at the junctures of the portions so flattened the second time and the remaining portions of said tubes, said tray-moving means includes means for moving said tray upwardly a third time for positioning said ends of said tubes in said gaps a third time, and

said jaw-moving means includes means for moving said movable jaw plates toward said fixed jaw plates 21 third time for again flattening the ends of said tubes and completing multiple folding of said ends of said tubes.

11. A device as recited in claim 10 in which:

said tray-moving means moves said tray upwardly higher said second time than the first time thereof, and moves said tray upwardly higher said third time than said second time,

thereby to successively flatten portions of said ends of said tubes which include portions extending beyond tube end portions which have been flattened previously.

12. A device as recited in claim 10 in which:

said tray-moving means positions said tray adjacent said bending plate in a relatively higher elevation said second time than the relative elevation of the first position of said tray adjacent said bendingplate for facilitating the bending of the flattened tube ends at the bases of the flattened portions of said. tube ends by said bending plate upon said second movement thereof.

13. The method of providing a multiple fold in the end of a metal foil tube for accomplishing a closure thereof comprising the steps of:

flattending the open end of a metal foil tube between relatively movable members,

then releasing said flattened portion from said relatively movable members so as to leave said flattened portion unsupported,

then engaging the flattened portion and pushing said portion substantially normal thereto so as to pivot said flattened portion and bend said tube substantially at the juncture of said flattened portion and the adjacent part of said tube,

then again flattening said flattened portion and the adjacent part of said tube between relatively movable members to provide a flattened doubled-over portion, then releasing said flattened doubled-over portion from said relatively movable members so as to leave said flattened doubled-over portion unsupported,

then engaging said flattened doubled-over portion and pushing on said flattened doubled-over portion substantially normal thereto so as to pivot said flattened doubled-over portion and bend said tube substantially at the juncture of said flattened doubled-over portion with an adjacent remaining portion of said tube, and then flattening said doubled-over portion and said adjacent remaining portion to complete a triple fold and a closure for said tube.

14. The method of providing a multiple fold in the end of a metal foil tube for accomplishing a closure thereof comprising the steps of:

flattening the open end of a metal foil tube,

then engaging the flattened portion at a location adjacent the juncture of said flattened portion and the adjacent part of said tube and pushing said portion substantially normal thereto so as to pivot said flattened portion and bend said tube substantially at said juncture of said flattened portion and the adjacent part of said tube,

then again flattening said flattened portion and said adjacent part of said tube to provide a flattened doubled-over portion, then engaging said flattened doubled-over portion at a location adjacent the juncture of said flattened doubled-over portion with an adjacent remaining portion of said tube and pushing on said flattened doubledover portion substantially normal thereto so as to pivot said flattened doubled-over portion and bend said tube substantially at said juncture of said flattened doubled-over portion with said adjacent remaining portion, and

then flattening said doubled-over portion and said adjacent remaining portion to complete a triple fold and a closure for said tube.

References Cited UNITED STATES PATENTS 783,271 2/1905 Herbst 1l3-57 8/1945 Booth 11354 CHARLES W. LANHAM, Primary Examiner. 20 L. A. LARSON, Assistant Examiner.

US. Cl. X.R.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US783271 *Nov 2, 1903Feb 21, 1905Betts & Co LtdMachine for closing the bottoms of collapsible tubes.
US2381716 *May 20, 1942Aug 7, 1945Wallace & Tiernan IncCollapsible tube folding apparatus
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5829133 *Nov 18, 1996Nov 3, 1998General Motors CorporationFor an automotive vehicle parallel flow heat exchanger
Classifications
U.S. Classification138/119, 72/370.13, 72/370.12
International ClassificationB21D51/36, B21D51/16
Cooperative ClassificationB21D51/36
European ClassificationB21D51/36