US2512370A - Pulling machine - Google Patents

Description

June Z0, 1950 w. E. oDoNNEL Er AL 2,512,370

PULLING MACHINE Filed April 8, 1948 4 Sheets-Sheet 1 i, OOOOOOOOOOOOOOI JOOOOOOOOOOO-OOO OOOOOOOOGOOOOO J ATTORNEYS.

June 20, 1950 w. E. oDoNNl-:L ETAL 2,512,370

FULLING MACHINE Filed April 8,'1948 4 Sheets-Sheet 2 A TTORNE YS.

June 20, 1950 v w.f E. oDoNNEL ET AL 2,512,370

PULLING MACHINE Filed April 8, 1948 4 Sheets-Sheet 3 A TTORNE YS.

June 20, 1950 w. E. oDoNNEL ETAL 2,512,370

PULLING MACHINE Filed April 8, 19.48 4 Sheets-Sheet 4 gpm 'mi 1726.@ EL" i I J5 63 I 11g .I E6 3 5&5 W Z v 30 v ATTORNEYS.

Patented `une 20, 1950 PULLING MACHINE William E. ODonnel, Wilmington, Del., and Robert W. Garey, Baltimore, Md.; Miriam L. Preston executrix of said WilliamvE. ODonnel, de-

ceased Application April 8, 1948, Serial No. 19,708

-2 Claims. l

This invention relates to a pulling machine, which while capable of a wide variety of uses, is especially suitable for removing bars from stators or other like work pieces.

In traction motors it is a common practice to build a stator with eld bars which are disposed transversely around the circumference of the stator and separated by mica or other suitable installation. The removal and replacement of such bars is a diflicult and laborious operation. Even after heating the eld laminations to soften the mica insulation it requires a considerable force, persistently applied, to extract a bar. With the use of tools which have heretofore been available for such work, it sometimes takes an hour of exhausting labor to remove a bar. The device of the present invention makes it possible for a single operator to remove such a eld bar in about six minutes.

The principal object of our invention is to provide a power driven, portable, pulling machine capable of being easily brought to the work piece and of gripping and pulling the bars with a continuously applied force of appropriate magnitude, whereby such bars may be mechanically extracted in a short period of time.

A further object of the invention is to provide in such a machine means for adjusting the position of the bar extracting mechanism and for bracing the same against the work piece so that the pulling force may be most advantageously applied.

Other more specic objects and advantages of the invention, including those derived from simplicity of manufacture and ease of assembly of the parts of the machine, will become more fully apparent from the description, as hereinafter set forth, of one embodiment of the invention, having reference to the accompanying drawings, whereof:

Fig. l is a side elevation of a bar pulling machine of our invention, showing the same in the process of extracting an auxiliary bar from a stator, and with certain parts broken away and shown in section.

Fig. 2 is a plan view of the same.

Fig. 3 is a vertical end view of the machine as seen from the left of Fig. 1 with parts of the gear casing broken away to better disclose important features.

Fig. 4 is a transverse vertical section of the machine taken as indicated by the lines .and arrows IV-IV in Fig. 1.

Fig. 5 is a longitudinal vvertical section of the mechanism for driving the extracting means,

taken as indicated by the lines and arrows V-V in Fig. 2.

Fig. 6 is a transverse vertical sectional view of the gear casing, taken as indicated by the lines and arrows VI-VI in Figs. 1 and 5,

Fig. is a vertical sectional view, taken as indicated by the lines and arrows VII-VII in Fig. 4, of the screw elevating mechanism for the pulling machine.

Fig. 8 is an enlarged fragmentary perspective View of the end of the extractor bar showing a gripper connected therewith and clamped'to a main bar of the stator frame.

Fig. 9 is a similar fragmentary perspective view of the end of the extractor bar showing a gripper connected therewith and clamped to an auxiliary bar of the stator frame; and

Fig. 10 is an enlarged perspective view of the auxiliary bar gripper.

With particular reference to Figs. 1 and 2 of the drawings it will be seen that the pulling machine A of our invention is illustrated in associa tion with the stator frame B of a traction motol Such frame B is of a well known design, the pinion end being designated at 5I, the commutator end being designated at 52, and the eld being generally designated at 53. An auxiliary field bar 54 is shown in the process of being extracted. As more clearly shown in Fig. 3, the stator frame selected for illustration has therein a series of auxiliary eld bars 54 and main bars 55 disposed transversely around its circumference. It may be assumed that in the portion of the stator frame B shown at the right hand of the pulling machine in Fig. 3 the bars have been removed, whereas, in the portion shown at the left hand of the machine the eld bars 54 yand 55 are still embedded in the frame.

O-f course, it will be appreciated that the stator frame illustrated herein represents only one example of a work piece to which the pulling machine of this invention may be advantageously applied, and in using the term Work piece in the claims of this application, it is intended to include any motor frame or device wihch presents a similar problem as to the removal of bars or other kelements which are frictionally held therein.

The pulling machine A consists generally ot a portable frame having two sections: a ground engaging section including wheels l, a handle portion 8, whereby the machine may be readily transported to the work, and an upright pedestal 9, forming the principal support for the extracting mechanism; and an elevatable section which may be raised and lowered by a threaded rod Il within the pedestal 9. Although the ground engaging section of the pulling machine frame may be variously designed, it is preferred to employ tubular standards I2 which merge together at their upper ends to form the handle portion 8, and tubular cross bars I3 which are welded to the standards I2 and to the pedestal 9. Conveniently the pulling machine frame may have incorporated therein cylindrical receptacles, such as shown at I4, and l5, and a box I6, all for accommodating tools, spare parts and accessories.

As shown most clearly in Figs. l and 4, the elevating screw I I is operated by means oi ahand crank I1 pivotally connected to a stub shaft I8 which is journaled in a bracket I9 and carries a bevel gear 2l. As shown in Fig. r1, bevel gear 22 surrounds the elevating screw II and is internally threaded at 23 whereby its rotation serves to raise or lower the screw within the pedestal 9. Between the bevel gear 22 and the bracket IS, which is integrally attached to the pedestal 9, a thrust bearing 24 is interposed. In an obvious manner the turning of hand crank I1, depending upon the direction of its rotation, serves to raise or lower the elevatable section of the pulling machine.

At its upper end the elevating screw Il joins a sleeve 25 within which a threaded extractor bar 26 is journaled. The sleeve 25 joins a gear casing 21 within which `is mounted a worm wheel 28 having an internally threaded hub 29 meshing with the external threads of the extractor bar 25. As shown in Fig. 5, 'the worm Wheel 28 is restrained against lateral movement within the gear casing 21. Hence its rotation serves to advance cr retract the extractor bar 2S within the sleeve 25 of the pulling ymachine frame. An enlarged head'ii on the end of extractor bar 25 limits its advancing movement.

Worm wheel 28 meshes with a worm ,3l on ya shaft 32. As shown in Fig. 6, shaft 32 is mounted in bearings 33 within the gear casing 21, and one end of shaft 32 carries a spur gear 34 disposed within an adjoining, separate gear casing 35. Within gear casing 35 a pinion 31, mounted on the end of a shaft 38 and driven by a reversible electric motor 39, meshes with spurgear 34. Accordingly the motorr39 drives the worm wheel 23 through pinion 31 and worm 3l.

Attached to the top of gear casing 21 is a housing 4l which carries a control mechanism for motor 33. Such mechanism is not shown Ain detail but includes a snap switch 42, which determines the direction of rotation of themotor 31, A

and a control handle 43 whichfmay be turned to different positions, as represented by the numerals on thedial 44, to start, stop and regulate thespeed of the motor 39.

At one end of sleeve 25 there is an annular groove v45 .engaged -by flanged clips 46 bolted to the cross head 41. vThe hub 48 of cross head 41 surrounds extractorbar 26 in such manner that it may turn freely thereon. By means of the Aflanged clips 45 it is at all times held in abutting relation to the end of sleeve 25 vwhile it has capacity for relative rotation with ,respect to said sleeve. Furthermore the hub 48 of .cross head i1 is internally provided with a key 49 which engages in a key-way extendinglongitudinally through the threads of the extractor bar 25. In this manner the cross head 41, While restrained against relative rotation .with respect to extractor bar V26,-is free to slide rlongitudinally with respect to .the extractor bar.

Cross head 41 has sleeves 51 at each end thereof, and such sleeves carry therein spacer bars 58, paralleling the extractor bar 25, one at each side thereof, and so designed that they are adapted to engage the stator frame B. In order to render adjustable the eiective lengths of the spacer bars 5B, each is provided with a series of regularly spaced perforations 59 with which locking pins 6I engage to form releasable locking connections between the cross head sleeves 51 and the spacer bars 58. To prevent the locking pins 5I from vbeing removed from the machine they are desirably attached to the ends of chains 52, the other ends of the chains being secured to a ring 53Aon the `cross head 41. The cross head 41 with its spacer elements 58 serves to brace the portable frame of the pulling machine against the work while bars are being extracted from it. It will be seen that the reactive force exerted by the pull of the extractor bar is communicated to the sleeve 25 and thence to the `hub i8 of cross head il and through spacer bars 58 to the stator frame.

Atthe reduced outer end of extractor bar 25 a connecting pin 5d couples `the bar to a gripper which may take the form of a clamp as shown at 55 in Fig. 8. The clamp 65 has a yoke S5 at one end `and a pair of screws 61 at the other end which penetrate into a cylindrical bore 58 within which the correspondingly shaped end of a main field bar 55 is adapted to t.

`When it is desired to remove an auxiliary eld bar 54 the type of gripper shown at 55a in Figs. 9 and 10 is used. This gripper includes a yoke 55a connected to extractor bar 25 by pin 54 and has a bifurcated body 53a terminating in e. reduced head 55o having a rectangular aperture 1Ia. To grip the end of .an auxiliary eld bar 54 the laminated sect-ions 12a of the bar are passed through the aperture 11a of gripper 55a .f and are then separated by driving a wedge 13a between such sections, in the manner illustrated in Fig. 9. vDesirably .the wedge 13a has sawtoothed serrations 14a so that it will not easily become dislodged. When driven in place it spreads the laminated sections 12a so that they are rm'ly'held within the bifurcated body 68a of the gripper 65a.

The operation of the pulling machine will be fairly apparent from the above description of its constituent elements. When the machine is used in association with a stator frame, such frame may be conveniently mounted. on ra vwork bench, .such as shown at 15in Fig. l. If it is a large stator frame it may be found desirable iirst to mount it in one position and later, when half .of the bars 54, '55 are removed from half of its circumference, to rotate it through one hundred and eighty degrees, and then to proceed to remove the remainder of the bars. Generally it is desirable to heat the iield bars by an acetylene torch or the like to soften mica insulation around the iield bars before attempting to remove them.

When applying the pulling machine to a eld bar 54, 55 the appropriate gripper-65a, 65 is first mounted on the end of the extractor bar 29. The pulling machine is then transported to the work by wheeling it to a position near the bench 15. Thereupon Athe spacer elements 58 are initially adjusted, and by means of hand crank I1 the elevatable section ci the frame is raised to a height where the extractor bar 2B is in line with the 4iirst field bar to vbe removed. By means of the motor controls, the extractor bar25 may be brought .toa position where the eld bar can be clamped withinlthe gripper. Aftersuch coupling connection has been made between the extractor bar and the bar to be removed from the stator frame, a nal adjustment of the pulling machine and its cross head 41 brings the free ends of the spacer bars 58 into contact with the stator frame, with such ends spanning the iield bar, equidistant therefrom, and bearing against the stator frame at points on a chord across an arc of the stator circumference, as illustrated in Fig. 3.

It will be observed that the cross head 41 may be swung freely to any appropriate angle to brace the machine properly against the stator frame, such angle being desirably perpendicular to the plane of the eld bar upon which the machine is to Work. When the machine is thus adjusted with spacer elements 58 in contact with the work the motor 39 is set in operation in the proper direction to cause the extractor bar 26 to be retracted carrying with it the eld bar engaged by its gripper. The speed of the motor may be appropriately regulated according to the pulling force needed for extraction of the field bar. After removal of the first bar, the pulling machine is readjusted for application to a second bar, and the process is repeated until all bars have been removed.

Although we have described in detail one specinc embodiment of a bar pulling machine of our invention, it will be apparent that numerous changes may be made in the form of the machine, including particularly the manner in which it may be transported from one position to another (the term portable being used herein in its broad sense), the selection of mechanism for driving the extractor bar, and for elevating and depressing the extractor bar. It will also be apparent that various reversals of parts, and substitutions of equivalent mechanisms may be made, and that certain features of the invention may at times be used Without use of other features, all without departing from the spirit of the invention as defined in the annexed claims.

Having thus described our invention, we claim:

1. A pulling machine for withdrawing a plurality of annularly disposed elements from a work piece having an outstanding peripheral strip, comprising a frame, a sleeve on said frame, a threaded elongated extractor bar mounted for sliding and rotary motion within said sleeve, threaded means engaged with said threaded elongated extractor bar for longitudinally advancing and retracting said extractor bar, an elongated housing fixed to one end of said sleeve for enclosing said threaded means and providing spaced shoulders to prevent longitudinal movement of said threaded means, a peripheral groove-pro vided on the other end of said sleeve, a cross head carried at said other end of the sleeve, means fastened to said cross head and. engaged with said groove to prevent relative longitudinal motion between said sleeve and said head but allow rotary relative motion, a bore through the cross head through which the extractor bar extends, interengaging means between the cross head and the extractor bar to prevent relative rotary motion but to allow longitudinal relative motion, and a plurality of brace arms on said rotatable cross head for bracing said frame relative to a selected portion of the peripheral strip of the work piece during the period of application of extractive force on said extractor bar.

2. The apparatus as in claim 1 wherein the threaded means comprises a gear having an internally threaded hub, and the means fastened to cross said cross head constitutes a clip fastened at one end to said cross head and having an inturned flange at the other end in engagement with said groove, and wherein said interengaging means constitutes an elongated keyway in said extractor bar and a key carried by said cross head.

WILLIAM E. ODONNEL. ROBERT W. GAREY.

REFERENCES CITED The following references are of record in the file of this patent:

vUNIIIEID STATES PATENTS Number Name Date 1,090,920 Knight Mar. 21, 1914 1,334,151 Gregovsky Mar. 16, 1920 1,513,031 Brown Oct. 28, 1924 1,760,989 Lewis June 3, 1930 1,889,135 Shaier Nov. 29, 1932

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