US2305961A - Electric forging apparatus - Google Patents

Description

Dec. 22, 1942; E. GA SPAR ELECTRIC FQRGING APPARATUS Filed Marc}; 1 1, 194]. 2 Sheets-Sheet l M, M s m Dec. 22, 1942. E. GASPAR 2,305,961

ELECTRIC FORGING APPARATUS Filed March 11, 1941 2 Sheets-Sheet 2 Patented Dec. 22, 1942 ELECTRIC FORGING APPARATUS Emeric Gaspar,

or to Omes Limited, ish company Application March 11, 1941,

Barnes, London, England, assign- Barnes, England, a Brit- Serial N0. 382,817

In Great Britain November 2, 1939 5 Claims.

This invention comprises improvements in or relating to electric forging apparatus.

The present invention comprises an electric forging apparatus having in combination two vice-electrodes close together, each adapted to grip one of two workpieces at one end of the portion thereof which is to be forged, a vice-electrode or two vice-electrodes electrically connected together, to grip the other end of the portion to be forged so that the two workpieces are electrically connected in series with one another, and means to move the electrodes which grip one end of the workpieces to forge them simultaneously while they are gripped by the electrodes.

Electric forging machines usually comprise two electrodes for engaging the workpieces, one of which at least is ordinarily a vice for gripping the workpiece, in combination with an hydraulic cylinder and ram for applying the forging effort to the workpiece and a transformer connected to the two electrodes so as to heat the workpiece by electric current passed therethrough.

According to one feature of the present invention two forging mechanisms of the type just described are disposed side by side with their electrodes close together, two of the adjacent electrodes of the respective mechanisms being connected electrically together and a single transformer connected to the remaining two electrodes.

Alternatively, there may be provided electric forging apparatus comprising a vice-electrode having jaws, each jaw being sub-divided into two portions electrically insulated from one another and connected to the two terminals of a supply transformer, the two portions of each jaw being so formed that each portion accommodates one workpiece, a second electrode which engages both said workpieces, and means to move said second electrode relatively to the first to effect a forging operation. The un-subdivided electrode therefore fulfills the function of the two electrodes which are connected together in the first-described arrangement while the subdivided electrode fulfills the function of the two electrodes which are connected to the transformer. In other respects with both arrangements standard upsetting or tension forging machines can be employed so that conversion to series working, which is sometimes desirable for high output or dealing efiiciently with large workpieces, can be brought about rapidly.

The means to move the electrodes may be such as to draw them away from each other so that the workpieces are drawn out during the forging operation, if desired, until they form four pointed workpieces.

The following is a description by way of example of certain forms of apparatus in accordance with the invention, reference being made to the accompanying drawings, in which:

Figure 1 is a plan of one form of apparatus with certain parts broken away;

Figure 2 is a view of a portion of the machine shown in Figure 1 with the parts in a different position;

Figure 3 is a detail perspective view of one of the vice-electrodes of the machine shown in Figures 1 and 2;

Figure 4 is a diagrammatic view of an alternative form of apparatus.

Referring to Figures 1 to 3, the forging machine comprises a bed H having horizontal guideways l2, l3 on its upper surface which support two vice-electrodes M, l5, The vice-electrode I4 is secured to the bed by set-screws l6 and the viceelectrode !5 is adapted to slide along the guideways l2, 13. The sliding movement is imparted to the vice l5 by means of a double-acting hydraulic ram l1 working in a cylinder 18 and supplied with hydraulic pressure by pipes I9, 20.

As best seen in Figure 3 the vice-electrode I4 is insulated from the bed H by insulation 2| and it comprises a lower fixed jaw in two parts 22, 23, the two parts being insulated from one another by insulation 24. Above the fixed jaw there is a movable jaw which is built up from two parts 25, 28, the two parts being insulated from one another by insulation 21. The shapes of the parts 25, 28 can best be seen from the plan, Figures 1 and 2. The upper movable jaw 25, 26 is supported for vertical movement from a pad 28 on the lower end of a ram 29 which works in a vertical cylinder (it. The cylinder 30 is separated by a column 3| from the base of the vice Hi, but this column is shown broken away in Figures 1 and 2, and the ram 29 removed so that the shape of the vice-jaws below it can be seen more clearly.

The pad 23 is separated by insulation 32 from the vice-jaw portion 25, 26 and these jaws and the pad are secured together by suitable insulated studs which are not shown in the drawings. The hydraulic cylinder 38 is double acting and is provided with appropriate supply pipes for fluid under pressure so as to permit the vice-jaws to be raised or clamped down at will.

The portions 22 and 25 of the fixed and movable jaws respectively overlie one another and coincide in shape. They are provided with re- Figure 1, through the portions 22 cesses 33, 34 which permit them to grip firmly one end of a workpiece 35 (Figure 1). The other portions 25, 26 of the lower and upper vicejaws are provided with similar recesses 36, 3'! which enable them to grip a second workpiece 38.

The two portions 25, 26 of the upper vice-jaw are each separately connected to their corresponding portions 22, 23 of the lower vice-jaw by means of flexible connectors 39, 40. Each half of the lower vice-jaw, that is to say the parts 22, 23, is connected to one of the terminals of the secondary winding 4| of a step-down transformer, the primary winding 42 of which is supplied with alternating current at a suitable voltage.

The movable vice I5 comprises a standard 43, similar to the standard 3| of the fixed vice, which supports a vertical hydraulic cylinder similar to the cylinder 30 having a ram on which is mounted a vertically movable vice-j aw 44. The vice-jaw 44 Works above a lower vice-jaw formed on the base l5 of the movable vice, and is provided with two recesses to engage the other ends of the workpieces 35 and 38. By this means an electric circuit is formed, as will be seen from and 25 of the fixed vice from one of the terminals of the transformer through the workpiece 35, thence through the jaws of the movable vice and back through the workpiece 38 and the portions 23, 26 of the fixed vice to the other terminal of the transformer.

Upon mounting two workpieces such as 35. 38 between the vices with the parts in the position shown in Figure 1, the workpieces become heated in series with one another and when they have been brought to forging temperature, the movable vice I5 is drawn away from the fixed vice I 4 until four pointed workpieces 35a, 35b, 38a, 3822 are produced, as shown in Figure 2. If the parts are suitably proportioned, the result is to produce four bullets or shell forgings at a single operation. These can be finished while still hot.

Owing to the fact that the workpieces are in series with one another, they are necessarily brought to the same heat and this is particularly important in the case of tension forging, as just described, because the cross-section of the workpieces decreases as the forging proceeds and were an attempt to be made to forge two workpieces into four pointed forgings simultaneously, connecting them in parallel with one another instead of in series, the result would probably be that one or other of the workpieces would become overheated at the point during the forging. It will be understood that if desired, instead of using the apparatus shown in Figures l-3 for tension forging, as just described, it could be used for putting pressure upon the workpieces so as to upset the heated parts between the vices.

It is a further advantage of this mechanism that if desired anvil faces could be arranged on the movable vice member I 5 and the fixed vice 14 could then be employed to grip two workpieces and upon contact with the anvils to produce upset heads on the ends of them.

Referring now to Figure 4, this shows a case where two separate forging mechanisms are provided which are electrically connected together, in such a way as to achieve a result similar to that obtained in Figure 1, and by adopting this method it is posssible to modify existing machines so that they work in series with one another. In the drawings, 50 represents a fixed vice-electrode of one machine having a lower jaw 5| corresponding to the lower jaw portion 23 of Figure 3. Opposite this is a movable jaw 52 having a lower jaw portion 53. It will be understood that upper jaws are provided which are clamped against the lower jaws by means of hydraulic cylinders and rams, as in the case of the construction illustrated in Figure 3. Each vice of this pair serves to grip one end of a workpiece 54 and a hydraulic cylinder 55 provided with a ram 56 will provide the power to draw the movable vice 52 away from the fixed vice 50.

Similarly, there is arranged adjacent to the above a second similar ram consisting of a fixed vice 60 with a jaw 6|, a movable vice 62 with a jaw 63, and a hydraulic cylinder 65 with a ram 66. This ram grips a second workpiece B5. A step-down transformer 10 provided with two terminals ll, 12 is connected as to one terminal to the vice other terminal to the vice 60 by the flexible connection 14. The two movable vices 52 and 62 are electrically connected together by a flexible connection 15. Thus the workpieces are in series with one another and owing to the causing any tendency on the part of the other to jam.

I- claim:

1. An electric forging apparatus having in combination two vice-electrodes close together, each adapted to grip one of two workpieces at one end of the portion thereof which is to be forged and to hold them parallel with one another, a duplex vice-electrode to grip the other ends of both the workpieces, so that the two workpieces are electrically connected in series with one another, and means to move the electrodes relatively to one another parallel to the length of the workpieces to forge the workpieces simultaneously while they are gripped by the electrodes.

2. Electric forging apparatus comprising a vice-electrode having jaws, each jaw being subdivided into two portions electrically insulated from one another, each of the portions of each jaw being electrically connected to one of the two terminals of a supply transformer, the two portions of each jaw being so formed that each portion grips part of one workpiece and cooperates with a corresponding portion of the other jaw, a second electrode which engages both said workpieces, and means to move said second electrode relatively to the first to effect a forging operation.

3. A process of manufacture of projectiles consisting in mounting workpieces from which they are to be made (each workpiece containing sufficient metal to make two projectiles), in pairs in vice-electrodes so that they extend parallel to one another from one vice-electrode to another, one of these vice-electrodes being electrically subdivided so that the workpieces are electrically connected in series with each other, passing an electric current through the workpieces by means of the vice-electrodes and, when the workpieces have been heated to forging temperature, simultaneously and uniformly drawing them apart by a movement parallel to the length of the workpieces so as to form a number of pointed bullets simultaneously.

4. Electric forging apparatus having, in combination, two vice-electrodes close together, each adapted to grip one of two workpieces at one end of the portion thereof which is to be forged and to hold them parallel with one another, a duplex vice-electrode to grip the other ends of both the workpieces so that the two workpieces are electrically connected in series with one another and single means to draw the duplex vice-electrode and the other electrodes away from each other so as to simultaneously and uniformly draw the two workpieces out into four pointed workpieces.

5. Electric forging apparatus comprising, in combination, a bed-plate, a hydraulic cylinder thereon, a vice-support slidable upon the bedplate and operatively connected to the hydraulic cylinder to be moved along the bed-plate thereby, vice-jaws in the vice-support adapted to grip two workpieces so that they extend therefrom in a direction parallel with the bed-plate, a second vice-support secured to the bed-plate in line with the first said vice-support, fixed and movable vice-jaws upon said second vice-support both of which vice-jaws are subdivided electrically into two portions so that corresponding fixed and movable portions register with one another, one pair of corresponding portions being adapted to grip one of the workpieces and the other pair the other workpiece, and means to supply electrical energy through said sub-divided vice-jaws for heating the workpieces, using one pair of corresponding fixed and movable portions as one electrode and the other pair as another electrode.

ElVlERIC GASPAR.

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