US2896483A - Device for cold welding exhaust tubulations - Google Patents

Description

1959 GJJ. AGULE ETAL 2,896,483

mavxcsron cow WELDING EXHAUSTTUBULATIONS Fild June 1. 1954 s Sheets-Sheet 1 FIG. I

INVENTORS GEORGE J. AGULE and ALBERT F ENGLER TORNEY Jul 28, 1959 G. J. AGULE ETA]. DEVICE FOR cow WELDING EXHAUST TUBULATIONS Filed June 1. 1954 3 Sheets-Sheet. 2

INVENTORS M M R m Y MT R GE A AF m J Q m T uwR RE 8 EL GA Y B July 1959 I J. AGULE ET AL 2,896,483

osvzcs FOR cow WELDING EXHAUST TUBULATIONS Filed Jude 1. 1954 I s Sheets-Sheec a INVENTORS GEORGE J. AGULE and ALBERT EQENGLER AT ZRN EY ed S ate Pat I JEVICE FOR COLD WELDINGEXHAUST .TUBULATIONS Application June 1, 1954, Serial No. 433,601

1 Claim. (CI. 78-82) V This invention concerns a novel pinch-off device for exhaust tubulations such as are used on electron tubes in order to permit them to be connected to an exhaust pump. More specifically, this invention consists of a pinch-off device which will properly position itself relative to the exhaust tubulation which is to be pinchedoil so that no mechanical damage can be caused the exhaust tubulation or the envelope to which it is attached.

It has become common in the electron tube industry and elsewhere where vacuum-tight or gas-tight sealing off is required to employ a metallic exhaust tubulation which may be sealed vacuum-tight or gas-tight by mechanically pinching together its side 'walls into a cold weld. Such an exhaust tubulation is advantageously composed of copper and. is pinched-off by using a pair of rounded jaw pinchers as described in US. Patent No. 2,427,597, the invention of Garner. sealing off tubulations has proved extremely useful and has accomplished great savings in both time andmoney.

One problem which has been encountered with manually operated pinchoff devices of the sort suggested by This method of Gamer has been the tendency for the operator to twist i the pliers or apply uneven forces to the pliers. As a consequence the tubulation may break or the tube structure may be damaged due to these undesirable forces applied to it while pinching it off. However, to date only hand pinchers or pliers have been employed and Patented July 28, 1959 present invention is preferably hydraulically actuated so that it will be capable of pinching-01f tubulations of great size. This is particularly advantageous because heretofore in pinching-01f tubulations of great size, the additional amount of force required caused the operator to use much more strength. Such additional tax on the strength of the operator might lessen his control and when misapplied could more readily cause damage to the tubulation or the envelope to which it is attached than would be the case were the relatively small amounts of force used with small tubulations misapplied. The hydraulic unit is capable of pinching-01f tubulations of any size with essentially the same case with which it will pinch-off the smallest tubulation.

A small degree of self-adjustment of one of the jaws may be provided in the structure of the present invention so that the jaws may adjust to remain essentially parallel to one another throughout the pinching operation. If the jaws become sufliciently out of parallel, a satisfactory cold weld is not obtained all the way across the tubulation. Because it is the nature of the preferred construction of the present invention to lend support at one side of the jaws, if the forces become sutficient, the support may yield so that fixed jaws will not be exactly parallel. If provision is made for self-adjustment, however, the jaws will tend to maintain parallelism because the tendency to distribute forces evenly over the supporting opposed surfaces will produce such a result, Thus, it is possible to insure complete seal off each time by use of the self-adjusting jaws. The device of the present invention may be made quite flexible byproviding for its elevation to difierent heights so that the jaws may be at the desired level for pinching-off. A preferred way to produce this elevation is to employ legs for the frame which are pneu mantically actuated cylinders wherein additional air pressure will cause an increase in the length of the leg.

Another feature of the present invention which adds to its flexibility and usefulness is the flexible mounting device whereby the support for the jaws is coupled by flexible yieldable mounting members to the frame so that a small amount of vertical adjustment is possible. Such vertical adjustment prevents damage to the tube structure as the tubulation is pinched-off due to forces which occur in the axial direction due to elongation of the tubulation.

may be used to automatically pinch-off exhaust tubula- 1" jaws, preferably composed of a hard material. like tungsten carbide, as taught by Garner. At least one of these jaws is mounted upon a movable ram. A frame for supporting the jaws opposite one another is provided so that the ram will drive one jaw against the other.

The tubulation to be pinched-off is positioned between the jaws. Finally, the frame is provided with means which will permit free movement of the frame while maintaining the plane of the jaws. This is movement relative to the supporting table or reference plane above which the tubulation is pinched-off.

In addition to being self-adjusting, the device of the pinchthe legs to raise or lower the height of the pinching jaws relative to the supporting reference plane.

Fig. 4 illustrates one of the legs showing the flexible coupling between the frame and the support for the jaws. Fig. 5 illustrates in partial section a flexible coupling between the support and the frame permitting some vertical yield in the structure.

Referring to the drawings, and in particular to Figs. 1 and 2, it may be seen that the primary frame members 10 and 11 are of C-shape. The two C-shaped members define a rectangular frame wherein one long side of the rectangle is removed. These C-shaped members should have suflicient thickness to be relatively rigid. Said 0- shaped members are connected by four vertical columns generally designated 12 of identical construction at the four corners of the rectangle. V t

Actual support for the jaws is provided by a support member generally designated 15 whichis advantageous- I ly adapted to accept a hydraulic ram to form a structure sometimes called a hydraulic C-clamp. This support has a webbed C-shaped connection piece 16 which .interconnects two vise-like jaws 17 and 18. These jaws are rounded and are advantageously composed of tungsten carbide rod mounted so that rounded surfaces of the two members will abut one another when the jaws are closed. These jaws may, in turn, be embedded in steel block 19 and piston 20 of the hydraulic ram. Block 19 and piston 20 advantageously embrace more than half the circumference of the cylindrical jaws 17 and 18, respectively, and so hold them fast, leaving the exposed areas of the jaws for pinching.

The hydraulic ram is composed of a cylinder 21 in which the piston 20 rides. The part of piston 20 which accepts jaw 18 may be either an integral part of the piston or an adapter joined to the piston. In either event, fluid is fed into cylinder 21 through coupling 22 in order to urge the piston out of the cylinder. Cylinder 21 of the hydraulic ram is supported by the support member 15 within its tubular flange 23 which closely engages the side walls of said cylinder.

7 Block 19 which supports jaw 17 is supported in fixed anvil-like member 25 by means of pin 26 which is snugly accepted by member 25, but loosely engages block 19. Block 19 has a rounded back edge. As may be seen in Fig. 1, in order to preserve the alignment'of the jaws, block 19 is free to shift its position in a sort of swivel motion within the plane of the jaws, as will be described later. Member 25 is cylindrical in shape and has a shoulder between larger and smaller diameters. The smaller diameter is accepted by tubular flange of C-support member 15 which flange snugly engages the smaller diameter portion of anvil member 25 so that its shoulder is opposed by the tubular flange 33.

Because piston 20 may have a tendency to rotate in its cylinder, thereby misaligning the jaws, it is usually a wise precaution to supply some interconnecting means 28 to prevent rotation of the jaws. This interconnecting means may consist of a bar which is aifixed to member 25 by bolts or other appropriate means. Bar 28, in turn, bears a guide 28a which is engaged by slot 29 in piston 20. It will be noted that piston 20 is generally cylindrical in cross-section except for that part of piston 20 which directly engages jaw 18, which part is rectangular in section. The cylindrical portions vary in diameter, the part which is always outside the cylin der having a diameter larger than the diameter of the cylinder and having groove 29 therein.

C-shaped support 15 is advantageously mounted on frame using mounting brackets 35 and 36 which may be joined together by cross-link 37. Mounting bracket 35 is advantageously provided with a cylindrical hole which snugly engages the outside diameter of the cylinder 21 of the hydraulic ram. Bracket 36 is provided with a cylindrical hole which snugly engages the cylindrical surface of anvil member 25. V

The mounting brackets may be supported on the frame through special flexible mounting members, four of which are employed at distributed points. As may berseen in Figs. 4 and 5, it is possible that the mounting members may extend between the legs 12 and the mounting brackets or bet-ween the actual frame portion 10 and the mounting bracket. Each of the mounting members consists of an annular flexible pad 40 of rubber or similar material at whose inside diameter the thickness may be increased to engage sleeve 41 over its entire length. At its outside periphery and embedded in the edge thereof to extend radially is planar annular member 42. The resilient structure formed thereby is supported by passing a bolt 43 through the sleeve and engaging it in a threaded hole in annular bracket 35. The bolt may be held in place by washer 44 which I prevents the head of the bolt from pressing directly on sleeve 41. Annular ring 42 rests atop frame member 10 or leg 12 over an aperture therein so that only the ring 42 touches the frame member. The ring 42 may be fixed in place by welding or in any other suitable manner. This construction'because of the resilient web between the ring 42 and the sleeve 41 permits the vertical adjustment of the structure. Such adjustment may be necessary when the tubulation is effectively elongated as it is pinched-off in order to permit the jaws to maintain their position.

The legs of this structure are advantageously cylinders 46 which contain a piston member 47 and a pneumatic connection through a manifold line generally designated 49. Air pressure may be fed to this manifold through tubing 50 which is connected to a control valve 51 beyond a speed control valve 52. The various 7 valves and couplings employed in this pneumatic sysoff on the exhaust tubulation. Raising or lowering the level of the jaws is accomplished through the introduction or release of air within the legs of the structure. The legs may alternatively be adjustable manually or by some means other than pneumatic, hydraulic or other fluid means. The convenience of the pneumatic or a fluid system is immediately apparent, however. Introduction of the air into the hollow cylindrical legs 46 will cause the piston 47 therein to be driven out of the chamber and hence will effectively lengthen the leg. The speed control valve 52 will assure that the lengthening process will not occur abruptly, but rather will occur with smoothness and ease. The control valve serves merely to open or close the pneumatic system.

When the-jaws 17 and 18 are at the desired level, the device is moved into position so that the tubulation lies between the jaws 17 and 18. Stop member 59 held in place by bolts 60 to the frame or the guide 28 serves to center the tubulation between the jaws 17 and 18 opposite pin 26. Thereafter, the hydraulic ram is actuated by the introduction of fluid into the cylinder to drive the ram forward toward the anvil. As the ram moves forward, the device moves on its casters 55 and; readjusts its position until the tubulation is square- 1y between the jaws. Then as the tubulation is squeezed and deformed between the jaws 17 and 18, the position of the frame of the structure is still able to shift to relieve any stresses which might otherwise be imposed upon the exhaust tubulation or the structure to which it is connected.

As the jaws are brought together, jaw 17 may tend to move out of parallel with jaw 18, and it is permitted to do so beacuse of its loose connection with pin 31.

. However, as the jaws are completely closed, the jaws at the other in response to the heavy forces applied. The

centering of the tubulation opposite pin 26 by stop 59 assures proper adjustment of the jaws into parallel position.

Many modifications of the structure described will occur to those skilled in the art. All such modifications of said structure withinthe scope of the claim are intended 5 to be within the scope and spirit of the present invention.

We claim:

A device for cold welding and severing exhaust tubulations of electron tubes, comprising a base having a pair of spaced jaw supports thereon, pinching and severing jaws carried by the respective jaw supports, one of the jaws being movable in a plane in a direction toward the second jaw to position the jaws in severing engagement with a tubulation therebetween, means for applying pressure to said movable jaw of an amount sufiicient to pinch the tubulation and to consequently elongate the tabulation in a direction normal to the plane of movement of the movable jaw, and resilient means connecting the jaw supports to the base whereby said jaw supports and jaws thereon are simultaneously movable in re sponse to elongation of the tubulation by said jaws in the direction of said elongation and normal to the plane of movement of the movable jaw.

References Cited in the file of this patent UNITED STATES PATENTS 672,552 Harrington Apr. 23, 1901 676,292 Wigtel June 11, 1901 851,398 Broadbooks Apr. 23, 1907 1,021,501 Bettendorf Mar. 26, 1912 1,165,174 Holmes Dec. 21, 1915 1,308,593 Kendall July 1, 1919 1,343,946 Warner June 22, 1920 1,556,735 Tiffany Oct. 13, 1925 2,243,013 Morey et a1. May 20, 1941 2,421,716 Rose June 3, 1947 2,427,597 Garner et a1 Sept. 16, 1947 2,456,125 Iohndrew Dec. 14, 1948 2,555,421 Ronan June 5, 1951 2,556,000 Temple Aug. 28, 1951 2,675,202 Kaemmerling Apr. 13, 1954 2,776,473 Bailey et a1. Jan. 8, 1957 OTHER REFERENCES Means of Connecting Aluminum Conductors" (Barnes), published by McGraw Hill, May 1954.

Publication: Shear Type Mountings of Lord Manufacturing Co., Erie, Pa. (Bulletin

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