US2161752A - Stripper for collapsible tube extruding presses - Google Patents

Description

H. F TEMPLE Jun 6, 1939.

STRIPPER FOR COLLAPSIBLE TUBE EXTRUDING PRESSES 2 Sheets-Shet 1 Filed Feb. 16, 1938 INVENT R Harold It" imp/e WI/A7 ATT RNEY

H. F. TEMPLE 2,161,752

STRIPPER FOR COLLAPSIBLE TUBE EXTRUDING PRESSES June 6, 1939.

2 Sheets-Sheet 2 Filed Feb. 16, 1938 INVENTOR Harold F Temple w w y Patented June 6, 1939 UNITED STATES PATENT OFFICE STRIPPER FOR COLLAPSIBLE TUBE EXTRUDING PRESSES Application February 16, 1938, Serial No. 190,751

Claims.

This invention relates to machines for extruding collapsible tubes from soft metal slugs and involves particularly the means for stripping the tube from the male die or plunger on which the tube is extruded, and is an improvement on the copending application of George W. Temple for Collapsible tube extruding press, Serial No. 52,294, filed November 30, 1935.

Considerable difliculty has heretofore been experienced in connection with the manufacture of aluminum collapsible tubes. Presses for making such tubes operate by squeezing a disc-like slug into a female die by means of a plunger to cause the upward extrusion of the metal from the die and around the plunger. Such presses usually dismount the tube extruded on the plunger, by means of a blast of air. Aluminum, however, differs from tin and lead and alloys thereof in that the extruded aluminum tube tends to ,adhere with considerable firmness to the plunger or male die and requires considerable force to remove it. Even a strong air blast is frequently ineffective to dismount such a tube. Aluminum tubes, even of small sizes, have heretofore been made only on comparatively intricate, heavy and slow presses which are uneconomical to operate for the formation of tubes of the smaller sizes.

My invention therefore contemplates the adaptation of a simple, inexpensive and comparatively light machine operating automatically and at comparatively high speed for the formation by extrusion of aluminum collapsible tubes of the smaller sizes by introducing into such machine a positive mechanical means for stripping the tube from the plunger after it has been extruded thereon.

This invention further contemplates the provision of a simple and inexpensive but positively acting and dependable stripping mechanism which is automatic in its operation and which may be used in connection with or instead of the customary air-discharge blast heretofore used for that purpose, to insure the certain removal from the male die of an aluminum tube extruded thereon, thereby making it possible to utilize comparatively small presses for the manufacture of aluminum tubes, which presses could not heretofore be used for that purpose because of the difficulty of removing aluminum tubes from the die.

The various objects of the invention will be clear from the description which follows, and from the drawings, in which,

Fig. 1 is a side elevation of a collapsible tubeextruding press to which my invention has been applied.

Fig. 2 is a fragmentary horizontal section of the same taken on the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary side elevation of the same, showing particularly the stripping mechanism in the position in which the stripping of the tube has begun. I

Fig. 4 is a similar view of the same, showing the positions of the parts just after the end of the stripping operation, as the parts begin to return to their initial positions. a

Fig. 5 is a similar view of the male die and the discharge chute, showing the cooperation thereof to remove a tube, should the tube not have been completely dismounted by the stripping mechanism.

In the practical embodiment of my invention which I have shown by way of example, I have illustrated the invention applied to the small press disclosed in said copending application, Serial No. 52,294, and in which the male die is tilted during the tube-dismounting operation. In said press, the frame l0 supports the various operating instrumentalities and at its upper end carries the main drive shaft l l on which'is fixed the gear I2. Meshing with said gear and mounted on the shaft I3 is the pinion l4, said pinion being driven by the pulley l5 also mounted on the shaft l3 and rotated through the belt IE or otherwise from a source of power not shown[ The drive shaft II is continuously rotated and rotates a suitable crank mounted thereon. Slidably supported for vertical reciprocation in the frame I0 is the cross head [8 suitably connected to the crank as by means of the connecting rod l9 and the pin 20.

It will be understood that a suitable hopper and suitable means for feeding slugs from the hopper to the female die 2| are provided but since said means are Well known in the art and form no part of the present invention, no illustration or description thereof is deemed necessary.

A plunger or male die 22 is reciprocated while in avertical position into and out of the female die 2| and causes the metal of the slug therein to squirt upwardly out of the female die and around the plunger 22 to cause the extrusion of a tube as 23 on the plunger. The upper part of the plunger is secured to the swingable member 24 which is pivoted as by means of the pin 25 to the downward extension 26 fixed to the cross head I8. The member 24 is provided with a rearwardly directed extension 21 adapted to en- 55 v gage the adjustable stop 28 arranged above said extension and carried by a member fixed to the frame of the machine. The member 21 also is arranged to engage the spring-pressed pin 29 disposed therebelow to swing said member and the plunger 22 carried thereby into the tube-dismounting or stripping position thereof at the proper time, reference being made to said copending application for a more detailed description of the mechanism now being referred to.

It will be understood that the plunger 22 while vertical and during the last part of its downward movement, enters the female die to extrude a slug fed into said die and then is moved vertically upwardly away from the die with the extruded tube on the plunger. On the last part of the upward movement of the plunger, said plunger is swung about its pivot 25 from the position shown in Fig. l to the position shown in Fig. 4 for the dismounting or stripping of the tube therefrom.

Normally, the upper surface of the swingable member 24 is maintained in contact with the lower surface of its reciprocating support 26 so that the plunger in entering the female die is maintained in its proper vertical position. For this purpose, the adjustable tension spring 39 is provided. In the raised or approximately uppermost position of the cross head shown in Fig. l, the extension 21 of the member 24 is in contact with the stop 28 and has, therefore, been swung about the pivot 25 to the inclined stripping position thereof. When the cross head moves downwardly, the spring 39 maintains the extension 2? in contact with the stop 28 during the first part of the downward movement, the pivot 25 moving downwardly at this time whereby the plunger is swung back to its initial vertical position until the extension is freed or. the stop whereupon the plunger is held by the spring 39 in its proper vertical tube-extruding position, the pin 29 aiding the spring to accomplish this result. On the vertical upward stroke of the plunger, the extension 21 reengages the stop 28 whereby continued upward movement of the cross head causes the plunger to swing toward the tube dismounting position shown in Fig. 4.

The means for dismounting or stripping the thus extruded tube from the plunger will now be described.

Said means may include a suitable air blast directed through a suitable opening in the plunger against the lower end of the extruded tube in the manner described in said copending application, or the dismounting means may be independent of the air blast depending on the size of the tube, the proportioning of the parts and the firmness'with which the aluminum. tube adheres to the plunger;

Pivotally mounted on the member 26 is a pair of transversely spaced arms 3|, 32 (Fig, 2) connected at their outer or front ends as b'y'means of the bolt 33 and swingable about the pivot mounted on the bolt 33, being confined between upward direction. The front end of the arm 44 1 is secured in a suitable recess in the bracket 38, while the rear end 45 of said arm is bifurcated and receives the plunger or male die 22 in the slot or opening 43 thereof, a front part of said plunger being at all times in contact with the semi-circular bottom 41 of said slot or opening,

urged thereto by the spring 40.

It Will be understood from the above description of the stripper arm 44 and its supporting vmechanism that the arms 44, 3i and 32 constitute a sort of toggle joint, so that when the plunger 22 is stationary, the position of the forked stripping end 45 of said arm 44 does not change; that is, the forked end does not move up or down on or relatively to the plunger. Nor does any relative movement of the stripping end 45 and the plunger occur on purely vertical movement of the plunger, unless such movement is great enough to cause the arms 3|, 32 to engage the fixed stop 48. When, however, the cross head of the machine is reciprocated enough to cause the tilting of the plunger hereinbefore described, the position of the forked end 45 changes, that is, said forked stripper moves up andzdown relatively to the plunger, thereby performing its tube-stripping function.

Means are provided for determining the limits of the movement of said fork 45 on the plunger and thereby determining the limits, extent and speed of the tube-stripping action thereof. Said means includes the normally fixed but adjustable cross pin or stop 48 carried at its ends by the plates 49, 50. Said plates are adjustably secured to the machine frame by means of suitable bolts or screws as passing through the slots 52 of the plates. the upper edges of the armsv 3| and 32 at the proper time, that is, during the movement of the plunger from its vertical to its inclined discharge position whereby the'arms 3| and 32 on and consequent upper movement of the rear ends 31 of the arms, are given a sudden downward movement to impart a quick downward stroke to the fork 4,5 and thereby to strip the tube 23 from the plunger; The tube. is discharged into the chute 53 and thence on to the conveyor belt 54 which may carry the tubes to another machine for further operation thereon.

As shown in Fig. 3, it will be seen that the 50 bifurcated end 45 of the arm 44 is of the proper 35,; The cross pin 48 serves to engage continued upward movement'of the member 26 size to engage the uppermost end of the extruded 7 tube 23 and of the proper shape to engage about one-half the circumference of the end of the tube. No stripping action occurs while the plunger is moved vertically out of the female die since the plunger and fork then move as a unit.

When, however, during the upward stroke of the member 25, the extension 21 engages the stop 28 and the tilting .rnovemet ofthe plunger toward its stripping position is begun, the plunger presses against the slot bottom 41 and swings the arm 44 against the action of the spring 40. Since the plunger swings upwardly at this time, the fork 45 moves downwardly relatively to plunger so that the stripping action is begun. When the cross head I8 is raised sufficiently to cause the arms 3|, 32 to engage the cross pin 48, the front ends of said arms are swung down,- wardly. The combined tilting of the plunger and the movement of the arms gives a quick and forceful downward impulse to said fork relatively to the plunger suflicient tocause the tube to move completely off the plunger, the toggle joint comprising the arms 3|, 32 and the arm 44 the spreading or opening at this time, while the plunger remains at all times in closely pressed contact with the fork 45 and acts as a guide therefor in its movement. On the downward stroke of the cross head, the above-described movements are reversed ready for a repetition of the operation, the spring 40 maintaining the fork 45 in pressed contact with the plunger.

By initially tilting the arms 3| and 32 relatively to the member 26, the uppermost position of the fork on the plunger is determined. Said tilting is accomplished by adjustment of the stop screws 38. Upward movement of said stop screws tilts the front ends of the arms 3|, 32 downwardly, thereby moving the fork 45 into a lower initial position against the action of the spring 43. Downward movement of said screws permits the spring 48 to raise the rear ends of said arms 3!, .32 thereby raising the fork 45 relatively to the plunger. Similarly, adjustment vertically of the position of the cross pin 48 determines the point where the quick discharge stroke of the fork 45 is begun as will be readily understood.

Should any part of the tube still remain on the plunger after the completion of the downward movement of the fork 45, the swinging of the inclined plunger from the position of Fig. 4 back toward the position of Fig. 1 (see Fig. 5), causes the partly stripped tube to engage the rear edge of the chute 53 thereby bending the tube off the plunger whereby even though the tube may be damaged under certain circumstances, it is, nevertheless, positively removed from the plunger and thereby prevents the extrusion of another tube on the outside of an unremoved tube on the plunger with consequent damage of jamming or breaking of the press parts.

It will be seen that I have provided a mechanism which while simple in construction, is positive in its action and insures the removal of tubes such as aluminum tubes from the plunger on which they are extruded rapidly and efficiently and which can be adjusted to overcome the natural adhesion of aluminum tubes to the plunger regardless of the extent of such adhesion so that damage to the machine is prevented.

It will further be seen that by insuring the removal of aluminum tubes from the plunger, it becomes possible to utilize a comparatively small and light press for efficient manufacture of large quantities of aluminum tubes of small sizes, which could heretofore be manufactured only on comparatively heavy and cumbersome presses at comparatively slow speed.

while I have shown and described a certain specific embodiment of my invention, I do not wish to be understood as limiting myself thereto, but intend to claim the invention as broadly as may be permitted by the state of the prior art and the scope of the appended claims.

I claim:

1. In a press for extruding collapsible tubes, a plunger having an extension thereon, means for vertically reciprocating said plunger and for also swinging said plunger about a horizontal axis, a bifurcated member having an opening therein for the reception of the plunger, and means for moving said member longitudinally of the plunger to strip off a tube extruded on the plunger comprising a pair of members constituting a toggle joint, one of said members carryind said bifurcated member at the lower end thereof, the other of said members being pivoted to said extension, a spring-pressedv hinged connection between said pair of members'andfan adjustable fixed stop in the path of said other of the pair of members.

2. In a press for extruding collapsible tubes, a vertical reciprocating plunger mounted for swinging movement about a horizontal axis, a stripping member movable longitudinally of the plunger, means operatively connected to the plunger for supporting said member for movement with the plunger and for longitudinal movement relatively thereto on the swinging movement of the plunger, and means for increasing the speed and extent of the longitudinal movement of the member relatively to the plunger comprising a fixed stop in the path of said supporting means adapted to engage andswing' said supporting means and thereby to swing saidv member during the combined vertical and swing ing movement of the plunger. I

3. In a press for extruding collapsible tubes,'a vertically reciprocating plunger mounted for swinging movement about a horizontal axis, a tube-stripping member embracing the plunger and movable longitudinally thereof, spring means for maintaining said member in pressed contact with the plunger and for urging said member toward its uppermost position on the plunger, and means for moving said member downwardly along the plunger to strip a tube therefrom including a fixed stop and pivoted means movable with the plunger and operatively connected to the member and arranged to engage said stop on the upward stroke of the plunger.

4. In a press for extruding collapsible tubes, a vertically reciprocating plunger mounted for swinging movement on a horizontal axis, an extension on said plunger, and means operated in part by the movement of the plunger for stripping a tube therefrom, saidmeans comprising a pair of arms pivoted together at their adjacent ends, one of said arms being pivoted to the extension, a spring urging the other of said arms toward the uppermost part of the plunger, means on said other arm for embracing the plunger and for engaging the upper end of a tube extruded on the plunger, and a fixed stop in the path of said one arm and adapted to engage said one arm toward and during the end of the upward stroke of the plunger to swing said one arm downwardly and thereby to cause said other arm and the plungerembracing means thereon to move downwardly along the plunger to strip the tube.

5. In a press for extruding collapsible tubes, a reciprocating plunger swingable about a horizontal axis, a member embracing the plunger and adapted to engage a tube extruded on the plunger, swingable means carried by and reciprocating as a unit with the plunger for supporting. the member for movement longitudinally of the plunger on the movement of the plunger, and fixed means in the path of the reciprocatory movement of the supporting means for swinging the supporting means in the proper direction to increase the extent of the longitudinal movement of the member relatively to the plunger.

6. In a press for extruding collapsible tubes, a reciprocating plunger swingable about a horizontal axis, a forked tube-stripping member having an open slot at one end thereof for the reception of the plunger and pivotally mounted at the other end thereof, a pivot pin for said other end of the member, a spring on said pin urging said member against the plunger and toward the upper end of the plunger, an arm hinged on the pin at one end and pivoted to the plunger near its other end, said member, pin, and arm moving with the plunger on the reciprocation thereof, and an adjustable stop in the path of said arm for swinging the arm and through the spring swinging the member relatively to the plunger to strip a tube therefrom.

7. In a mechanism for stripping a tube from a reciprocatory plunger, a spring-pressed tubestripping fork embracing the plunger, a toggle supporting the fork, and a pivot for the toggle on the plunger whereby the fork and toggle move as a unit with the plunger, and means for operating the toggle to move the fork relatively to the plunger to strip a tubetherefrom.

8. Inmechanism for stripping a tube from a reciprocating and oscillating plunger, a toggle pivoted at one end to the plunger and reciprocat- 9. In mechanism for stripping a tube from a movable plunger, a spring-pressed fork embracing the plunger and movable along said plunger on swinging movement of the plunger, and means for additively moving the fork along the plunger on upward movement of the plunger including a toggle connection between the plunger and the fork, and a relatively fixed stop in the path of the connection.

10. In mechanism for stripping a tube from a movable plunger, a spring-pressed stripping member embracing the plunger and mounted for movement by said plunger toward the lower end of the plunger on swinging movement vof the plunger, and means for imparting a sudden move ment to the member longitudinally of the plunger on vertical movement of the plunger including a toggle connection between the plunger and the fork, and means for operating said connection.

HAROLD F. TEMPLE.

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