US2659480A

US2659480A - Drawbench

Info

Publication number: US2659480A
Application number: US241372A
Authority: US
Inventors: Kreidler Alfred
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-08-16
Filing date: 1951-08-10
Publication date: 1953-11-17
Anticipated expiration: 1970-11-17

Description

Nov. 17, 1953 A. KREIDLER 2,659,480

DRAWBENCH Filed Aug. 10, 1951 2 Sheets-Sheet 2 J/V/f/V/W'? ale ad my Patented Nov. 1?, 1953 'l'TES PATENT FFICE Claims priority, application Germany August 16, 1950 6 Claims.

l' -his invention concerns draw benches used during drawing operations on rods and tubes.

A fault that often in the operation of draw-benches is that during the draw ng operation the teeth on the jaws of the drawing tongs bite so deeply int t e rod or tube being drawn that it is not immeo. ely released when the tongs are opened. She effort then required to withdraw the rod or tube from the tongs involves ex cessive expenditure of time and energy. In those draw-benches wherein, on conclusion of the drawing operation, the carriage deviates from the line or" pull during its return to the starting position, the danger arises that the rod or tube will be bent and the draw-bench damaged.

The present invention avoids these disadvantages by the provision of an ejector for the drawn rod or tube, mounted on the longitudinally moving tongs, and. a stop or similar device located on a fixed part of the draw-bench and designed to move the ejector into its operative position at the end of the drawing operation. For this purpose the ejector is mounted on the tongs in such a manner that it can enter between the opened jaws and eject the rod or tube. An especially suitable ejector for this purpose comprises a bell-crank lever, one arm of which (the ejector arm) passes between the jaws of the tongs when the other (the operating arm) strikes the stop.

It advantageous to combine a safety device with the ejector stop. The stop may be spring loaded, so as to be displaceable by the operating arm of the ejector in case of excessive resistance the rod or tube, should the latter become jammed on the tongs. The stop then serves to interrupt or disconnect the drive from the draw-bench and so bring it to a standstill. This be effected, for example, by means of an electric swit .1 which is turned to the off position by the movement of the stop, so that the machine brought to a halt whenever the ejector fails to eject the rod or tube from the tongs, and consequently no damage can be caused.

The invention will be described further, by way of example with reference to the accompanying drawings in which:

Figs. 1 and 2 depict in sectional elevation, and in sectional plan view on the line IIII of Fig. 1 respectively, one embodiment of the invention;

and

Figs. 3 and 4 show an alternative e ector rnechanism and, an emergency stop in more detail, Fig. 3 being insectional end view and Fig. 4 being a. plan view on the line IV--IV of Fig. 3.

On the upper longitudinal girders l of the draw-bench, the carriage 2 runs on rollers 3. For the sake of clarity, the draw-chain is not shown. Firmly secured to the carriage are the tongs E which are open top and bottom and within which are inserted obliquely the jaws 5. An operating lever 5 pivoted on the tongs serves in known manner to open and close the tongs by longitudinal displacement of the jaws 5. An ejector lever l, which is rigidly mounted on'the shaft 8, is free to move within the space between the tongs. The shaft 8 is pivoted between the lower part of the tongs, and rigidly mounted upon it, outside the tongs, is the operating lever ii which abuts against a lateral projection H on the tongs, under the force of a tension spring so, so that the operating lever 9 is downwardly directed whilst the ejector lever 7 lies in a horizontal position beneath the lower edge of the jaws of the tongs. The stop I2, which is secured laterally on to one of the girders of the drawbench, projects into the path of the operating lever 9. (Figs. 1 and 2.)

At the conclusion of a drawing operation, angular displacement of the lever 6 causes the tongs t to be opened by withdrawal of the jaws As the carriage 2 advances further, the lever B strikes the stop 1 2 and is displaced into the position indicated by chain-dotted lines in Fig. 1, thus causing the ejector lever 7 (the other arm of the virtual bell-crank lever l, 9) to be displaced in an upward direction between the open jaws 5 and to strike against the rod or tube, if this has not already automatically released itself from the tongs, thus forcing it upward and out of the tongs.

In the arrangement illustrated in Figs. 3 and 4, the stop 12 constitutes one arm of a lever pivoted at M in. a bearing l3 attached to the girder I, the other arm of whialever I5 abuts, under the force of a comparatively strong tension spring to, against a square-headed bolt i'l.- The actuating member of the driving-motor switch I8 is located within the orbit of the arm it of the lever I 2, l5.

If the jaws 5 have bitten so deeply into the rod or tube as to prevent its being ejected by the ejector 7, the lever 9 causes the lever l2; l5 to be displaced into the position indicated by chain-dotted lines in Figure 4, whereupon the arm 15 actuates the switch I8, with the result that the driving motor is switched off and the machine stops, and no damage is caused to its components.

It is of course understood that the lever l5, may

be replaced b other suitable means, such as, for example, a longitudinally displaceable slidebar, and also could be arranged to stop the machine by disconnecting a mechanical coupling.

I claim:

1. A draw bench comprising in combination a fixed base, a carriage adapted to be moved longitudinally along the said base, the said carriage including tongs adapted to hold material to be drawn, an ejector, means for mounting the said ejector on the said carriage for movement of said ejector through the said tongs, and a stop mounted on the said fixed base, operating means for said ejector, the said stop being disposed in the path of the said operating means which engage the said stop and upon continued movement of the said carriage causes said ejector to move through the said tongs and, thereby, to remove the drawn material from the said tongs upon abutting against the said stop.

2. A draw bench comprising in combination a fixed base, a carriage adapted to be moved longitudinally along the said base, the said carriage including tongs adapted to hold material to be drawn, jaws disposed in the said tongs, an i ejector, means for mounting the said ejector on the said carriage for movement of said ejector through the said jaws, and a stop mounted on the said fixed base, operating means for said ejector, the said stop being disposed in the path of the said operating means which engage the said stop and upon continued movement of the said carriage causes the said ejector to move through the said jaws and, thereby, to remove the drawn material from the said jaws upon abutting against the said stop.

3. A draw bench comprising in combination a fixed base, a carriage adapted to be moved longitudinally along the said base, the said carriage including tongs adapted to hold material to be drawn, jaws disposed in the said tongs, a twoarmed lever pivctally mounted on the said carriage for movement of one arm of the said lever through the said jaws in order to act as an ejector, and a stop mounted on the said base, the said stop being disposed in the path of the other arm of the said two-armed lever which engages the said stop and upon continued movement of the said carriage causes said one arm to move through the said jaws and, thereby, to remove the drawn material from the said jaws upon abutting the said other arm against the said stop.

4. A draw bench comprising in combination a fixed base, a carriage adapted to be moved longitudinally along the said base, the said carriage including tongs adapted to hold material to be drawn, jaws disposed in the said tongs, an ejector, means for mountin the said ejector on the said carriage for movement of said ejector through the said jaws, and a spring-loaded stop movably mounted on the said base, operating means for said ejector, the said stop being disposed in the path of the said operating means which engage said stop and upon continued movement of the said carriage causes said ejector to move through the said jaws and, thereby, to remove the drawn material from the said jaws upon abutting against the said stop, means for movement of the said stop from its normal position upon the said material becoming jammed, and the said stop including means for stopping the movement of the said carriage upon movement of the said stop.

5. A draw bench comprising in combination a fixed base, a carriage adapted to be moved longitudinally along the said base, the said carriage including tongs adapted to hold material to be drawn, jaws disposed in the said tongs, a twoarmed lever pivotally mounted on the said carriage for movement of one arm of the said lever through the said jaws in order to act as an ejector, and a spring-loaded stop movably mounted on the said base, the said stop being disposed in the path of the other arm of the said two-armed lever which engages said stop and upon continued movement of the said carriage causes said one arm to move through said jaws and, thereby, to remove the drawn material from the said jaws upon abutting of the said other arm against the said stop, means for movement of the said stop from its normal positon upon the said material becoming jammed, and

the said stop including means for stopping the movement of the said carriage upon movement of the said stop.

6. A draw bench comprising in combination a fixed base, a carriage adapted to be moved longitudinally along the said base, the said car riage including tongs adapted to hold material to be drawn, jaws disposed in the said tongs, a two-armed lever pivotally mounted on the said carriage for movement of one arm of the said lever through the said jaws in order to act as an ejector, and a spring-loaded stop removably mounted on the said base, the said stop being disposed in the path of the other arm of the said two-armed lever and upon continued movement of the said carriage causes said one arm to move through the said jaws and, thereby, to remove the drawn material from the said jaws upon abutting of the said other arm against the said stop, means for movement of the said stop from its normal position upon the said. material becoming jammed, an electric motor for driving the said carriage on the said base, an electric switch member for said electric motor disposed on the said carriage within the path of the movement of the said stop which engages said switch member upon movement of the said step, the said switch member being operated and the said electric motor being stopped by the movement of the said stop.

ALFRED KREIDLER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 371,311 Gracey Oct. 11, 1887 989,109 Berning Apr. 11, 1911 1,080,793 Vold Dec. 9, 1913 1,574,381 Entenmann Feb. 23, 1926 2,182,902 Nye Dec. 12, 1939 FOREIGN PATENTS Number Country Date 144,427 Germany Sept. 30, 1903