US2190889A - Drawbench - Google Patents

Description

Feb. 20, 1940. M. scHuNcK 2,190,889

DRAWBENCH Filed Aug. 26, 1937 55 sheets-sheet 1 35 M 7I A l-IEII Q) a s? ,Q Sk

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M. SCHUNCK Feb. 20, 1940.

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Patented Feb. 2o, 1940 f UNITED STATES PATENT OFFICE DRAWBENCH Main, Germany Application August 26, 1937, Serial No. 161,153 In Germany August 28, 1936 8 Claims.

` The invention relates to a drawbench and has `for its object a machine of this kind distinguishing itself by simple design and high output. Av

special object of the invention is to provide a l drawbeneh with a chain running in a horizontal plane round a frame formed in the shape of an I-(double T).

A second object ofthe invention is to provide a drawbench that automatically throws the 1 nished pieces from the bench on to a transporttruck.

A third object of the invention consists in providing a chain drawbench with a chain alternately movable in opposite directions and capable of also drawing tubes over a mandrel.l

Other objects of the invention and the advantages resulting therefrom may be seen from the following description of the invention.

The invention is shown in the drawings ac- 9 companying this specification in which Figure l is a side elevational view of the bench according to the invention,

Figure 2 a plan view and Figure 3 a cross sectional elevation on lines Figure 4 is a side elevational view partially in section of a special type of the drawbench for drawing tubes over the mandrel.

In the drawings 2 represents the vertical benchbedding mounted as usual on supports I. 'I'hebedding is formed in the shape of a girder having a middle rib with guides atthe top and at the bottom. The drawings show the middle-rib in the shape of a frame of box section. It is f advisable to give the latter approximately the breadth of the diameter of the driving chainwheel. 5 is the chain running on both sides in the plane of the central section of the I-shaped4 bench-bedding. The guides 6 and 1 are there i to guide it. 'I'he chain is driven by the chainwheel 3, while 4 represents a. pulley around which the chain can be reversed in its direction of movement, and through which the chain can also be re-stretched, should it have slackened considerably after working a long time. The guides 8 and 1 are formed preferably in the shape of Z-proles and riveted to the frame of the benchbedding. 'I'hey protect the vertically driven chain' from falling and sagging. On the side of the I drivethat is to say before the chain reaches the pulley 3-there are a set of tension-pulleys mounted on each side. They consist of stationary guide pulleys 8 and 9 and the tension pulleys II and I2, each of them being movable in the .i guides I0 transversely to the chain. Through a (o1. eos-7) compression-spring I3 the pulleys Il and I2 push the chain outwards, thus giving it a moderate preliminary tension.. If the drawing operation is carried out by the right hand chain, then the tension-'pulley' II is pressed down into the 5 bench by the straightened chain, while the tension pulley I2 moves outwardly and pushed away or restretches the surplus of chain running off the chain-pinion. If the tension-pulleys stretching the chain are properly adjusted there are no 10 chain troubles to be expected on any part of the bench. lOn the contrary, the chain will always smoothly run on to the chain-wheel. The driving chain-wheel 3 and reversing pulley 4 are mounted on vertical axles I4 and driven by a motor I5 l5 with the aid of gearing I6 and a pair of bevelwheels I1.

The chain moves the two work-gripper carriages I8 and I9, which are provided with the customary drawing-jaws or grippers and 2l Z0 for seizing the drawing-end of the work-piece. The carriages are guided by means of the pulleys 22 on the middle-rib of the bench-bedding. Thereby they are prevented from sliding oi the rib, partly by the upper plate 23 and the lower 25 plate 24, partly by the guides 25, 26, 21 or 28. The Work-gripper carriages are firmly coupled to the chain by means of the cams 28 and 30, note Fig. 3, catching into the chain-links. i These ca ms by running off the chain uncouple themselves easily at the end of the bench. In this simple way a clogging of the chain is made impossible. For coupling in again, it is only necessary tol push in the carriage by hand.

The middle axis of the drawing-operation, in 85 which the work-grippers or drawing-jaws 2Q or 2|V lie, can-according to this invention-be adjusted in such a. way that it may protrude a little over the outer edge of the lower guides 21- or 28. Consequently the pieces after being drawn can automatically fall into the transport-truck 3| or 32.

At the end of the bench-bedding a cross member 33 is xed, adjacent to which the'die- holders 34 and 35 are iixed which hold the dies and finto 45 which the latter are inserted. The disposition of these parts and the mode of fastening them is done in the usual way,1 need not go into details. On the side of the dies the necessary controldevices are provided for. By means of them, the motor can be controlled both ways to the eiect that the chain can also move in either direction. This control-mechanism being known to the expert, we may pass over its constructional de tails.

'Ihe adjustable reversing ipulley 4 gets its ten' sion from the screws I1 and 38 and by inserting A is put into a gripping device, consisting of a split inserted noz'zle 42 adjustable by means'of a handwheel I3. In its closed position the gripping mechanism clasps the mandrel-head 44 in a notch and holds it fast during the drawing operation. When it is opened the bloomor lump-tube Il can be put through the opening over the mandrel and the die 45 can be put on the latter, While, the drawing operation being terminated, thenished tube can be slipped oi. `On the other side Vthe f" mandrel is bedded in the grippingdevice 46, which is fixed on the transverse member 4l; The mandrel is supported by the pulleys 48, fixed to the .rocking-lever 49. According toithis method of ltubejrawing, the' gripper-carriage .50 is of a dfferent construction. Instead of. closed 'jaws' the i carriages v.are provided with an opening 5I,

through which the central-axis of the mandrel passes. T'his opening is wide enough to let the die through. The carriages are provided 'with devices 52 which hold ythe diefast during the 'drawing-operation and vwith flaps 53 for slipping the tube from the mandrel during the reverse movement of the carriage. The connection of the carriage with the chain is identical with the one in use ,in drawing through /dies-fas .described before. The flaps 52, lwhiclrare fitted to' hold the dies fast, or the vslipping off; device 53, are"`disposed in such' a way as to act upon the mandrel'twhile they are in operative position, but to offer passage by snapping open whilst they are not in action. For that purpose.' they/are movably mounted on bolts 54' and 55 on the carriages. The rollers 56 or 51, equally mounted in the carriage, immediately loo'sen the tubes on the mandrel as soon as the drawing operation is finished. To give `free passage, these rollers can'be i opened by lifting the flappivoted supporting armsi-j 'The bench (forinstance While drawing .bars

through the dies) works as follows according to the invention.

loaded with draw-ware is as usual standing on the service side of the bench. On the left4 and right sides ofthe bench are the transport-,trucks waiting for the finished articles. 'Ihe end of a workpiece, for instance of aba'r, being put (on the left side -of thebench) through the die into the jaws of the gripper-carriage, the latter is coupled in and made to run forward, that is to say to draw. During the forward-movement of this gripper-carriage and the corresponding back- Ward-novement of the gripper-carriage on" .the right side of the bench, the right side of the bench is already chargedor fed with a new. workpiece. The work-piece'on the leftside having' passed the die, falls automatically into the transport-truck without any additional manipulation or help given bythe operator. At this moment, whilst the gripping carriage is stationary on the right side of the bench at the working stand, the driving motor is reversed and the gripping carriage of the right vside of the bench' is coupled Seen by the operator the transport-truck in. Thus a drawing operation is started on this side, while the 'gripper carriage of the left side is running back. The drawing-operation being iinished on the right side and the drawn work-piece having fallen in the transport-truck, the motor or the'direction of the chain-drive is reversed,

' whereupon (the left side gripper-carriage being coupled in again) another drawing operation is performed here, while the right-side gripper carriage runs back empty. As shown the drawingoperation is performed now by the right'and now by the left chain portion, for which purpose only the direction of the chain-drive must be reversed every time. The operator of the bench may remain'standing at the head of the bench all the time only coupling and charging or feeding the `sides of the bench with draw-ware. vIt is easily understood that by this mode of working the output is considerably increasedjthe staff reduced and the production cost considerably lessened.

This working method offers many advantages. On the ,one hand the (bench works as a double bench with only one chain running. whereby the costs of the plant are reduced. On the other hand there is less light running and considerably less staff needed, as the throwing out ofthe finished work-pieces is automatically performed.

While drawing tubes over a mandrel the working method is as follows:

First insert the mandrel, then draw a bloomor lump-tube over it through the opened gripping device, 'fix the mandrel rmly and move the draw- .-ing`device over the fixed mandrel by means of the carriage, which is provided with catches.. A

step or offset 60 in the mandrel prevents in the usual way the tube from being taken'along.

`lWhile on one side the drawing and simultaneously.. rthe loosening is going on, the stripping oif takes' place on the other side not shown in Fig. 4. Here also the bench works'as a. double-bench offering the advantage of increased output and reduced staff. A special advantage is offered by the drawing of tubes over themandrel'on the drawbench according to the invention, if more than the usual one drawing-operation, is to beperformed on the same mandrelv over the tube without exchanging the mandrel. .If severalA drawings are to be made .successively on the same mandrel, then at the beginning of the drawing operation instead of one die, several dies of gradually diminishing diameter are put on the mandrel. The first die placed on the mandrel is 'of course thevlargest, and is connected to the carriage. Thecarriage is then run the length of the mandrel and one draw is thus made on the tube. Before the carriage is returned, the first die is disconnected, so` that the carriage alone returns to the starting point. The second die is then connected to the 'carriage and a second draw is made. Successive drawings are likewise made until the tube hasI reached the desired size. One time the right carriage is drawing, while the left is running'backwards and the other time the left isldrawingwhile` the right is running backwards. Because the reversemovement on one side coincides `with the forward-movement on the other, the light runningperiods and thereby the production-costs are con-- sliderably reduced.` V

I claim: 9'

l. A drawben'ch comprising abench-bedding having vertical sides, a chain extending adja- `cent said sides, at least one .gripping carriage,

means for mounting "and guiding said carriage along at least one of said vertical sides to carry means for coupling saidcarriage to said chain,

a work piece in a plane outside of and parallel to said sides, and means driving said chain alternately in opposite directions. i

2.. A drawbench comprising a bench-beddingframe in the form of an I.' a chain .means for mounting and guiding said chain substantially midway of and on opposite sides of said I, at least one gripping-carriage, means to couple the chain on to said gripping carriage,adrivingchain-wheel with vertical driving axle, a pulley with vertical axle for the chain, and means for driving the chain in both directions. l

3. A drawbench comprising a bench-bedding consisting of a vertical' middlerib, guides mounted on both sides of said middle-rib, a continuous chain supported by these guides on both sides of the middle-rib. two gripping carriages moved by means of the chain on b'oth sides of said middle-rib, devices to couple the gripping carriages onto the chain, a drive chain-wheel with vertical driving axle for the chain and means for driving the chain in both directions.

4. A drawbench comprising a bench-bedding having a vertical middle-rib andl plates protruding onl both sides over the middle-rib at the top and at the bottom, at least one die mounted on one end of the said bench bedding, a continuous chain supported about both sides of said middle-rib,jat least one gripping carriage moved by the chain, means to grip the articlesto be drawn, said means being moimted on said gripping-carriage in such a way that the projection oi the connecting linesfrom these means to the dies falls outside the plates, that are fastened underneath to the said middle-rib, devices to couple the gripping-carriages on the chain, a driving chain-wheel with vertical driving axle, a reversing-pulley with vertical axle for the chain and means for driving the chain in both direc- 5. A drawbench comprising a bench-bedding- !rame in the shape of a sole plate frame of box section, a chain mountedvertically and substantially midway of both sides of said frame, gripping-carriages running on the side walls oi said frame, means to couple said gripping-carriages on to the chain, a drive chain-wheel, a pulley, said driving chain-wheel and said pulley having a diameter corresponding approximately to the breadth of said frame, and means for driving the chain in both directions.

6. A drawbench comprising a bench-beddingframe in the shape of a sole plate frame of box section, a continuous chain supported about both sides of said frame, gripping carriages mounted for movement by said chain, mea-ns for driving this chain in alternate directions, elastic chain stretching devices for restretching the non-drawing portion of the chain by means of deviation, but allowing the drawing portion to run through in a straight line from said driving means to a gripping carriage.

7. A drawbench according to claim 6 comprising sets of tensionand guide-pulleys placed near the'drlving chain-wheel before the on-run and the oit-run of the chain.

8. A drawbench comprising a bench-beddingframe in the shape of a sole plate frame oi' box section, a chain supported about both sides of saidv frame in a horizontal plane, at least one gripping carriage, means including said chain for moving this gripping carriage along the sides of said frame. means for fastening a magndrel` at the sides of the frame of the bench-bedding and means for drawing tubes and for loosening the -tubes from the mandrel which are mounted on the gripping` carriage.

Max ecrnmcx.

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