US2425219A - Track shoe - Google Patents

Description

Aug. 5, 1947. R. Q. ARMINGTON 2,425,219

TRACK SHOE Filed Nov. 8, 1943 2 Sheets-Sheet l [I [III A. M 06 I7 g-l-E INVENTOR.

Rama/v0 Q ARM/NGTON nrromvsvs 1947. R. Q. ARMINGTON 2,425,219

TRACK SHOE Filed Nov. 8, 1945 2 Sheets-Sheet 2 /g INVENTOR.

AA wvo/vo Q. ARM/Nara BY H 22%.

ATTORNEYS Patented Aug. 5, 1947 TRACK SHOE Raymond Q. Armington, Shaker Heights, Ohio, asslgnor to The Euclid Road Machinery Co., Euclid, Ohio, a corporation of Ohio Application November 8, 1943, Serial No. 509,391

6 Claims. 1

This invention relates to improvements in crawler tracks of the type wherein rollers are provided intermediate the crawler frame and the shoe which supports the same upon th ground. More particularly it relates to improvements in means for supporting the rollers and for lubricating the roller bearings.

An object of the present invention is to provide simple but sturdy means forsupporting a roller in a track shoe for the purposes described.

Another object of the invention is to provide a roller so supported that it is easily removed when repairs are necessary.

Another object of the invention is to provide novel lubricating means for the bearings of the rollers and, more particularly, a novel combination between the roller support and bearing lubricating means,

Other objects and advantages of the invention will b apparent from the accompanying specification and drawings, and the essential features thereof will be set forth in the claims.

In the drawings,

Fig. 1 is a side elevation of a portion of an endless crawler track embodying my invention;

Fig. 2 is an enlarged sectional view of the same taken along the line 2--2 of Fig. 1;

Fig. 3 is a top plan view of one of the shoes of Fig. l with the roller and tread pins removed.

Fig. 4 is a side elevational view of another form of track shoe utilizing my invention in a slightly modified form; the central portion of this view illustrates diagrammatically a detail of construction in connection with Figs. 2 and 5.

Fig. 5 is a transverse sectional view similar to Fig. 2 showing a roller and shaft assembled in the shoe of Fig. 4; while Figs. 6 and 7 are detail views of certain parts of Fig. 5.

I have chosen to show my invention embodied in a crawler of the type shown in a copending application of Stewart F. Armington, Serial No. 493,555, filed July 5, 1943, now Patent No, 2,411,- 408, dated Nov. 19, 1946, although it will be understood by those skilled in this art that my invention may be applied to other types of tracks.

In this type of crawler device a main frame Ill is adapted to be mounted by trunnions at the point It on the vehicle to be moved. This frame is supplied with parallel endless guide rails l2 adapted to be engaged by rollers l3 which in turn ar supported by shoes l4 which engage the ground. There is a series of these shoes connected together by tread pins l5 and each shoe carries a set of rollers l3.

The shoes are of sturdy and novel construction and comprise a base plate I6 adapted to engage the ground and' carrying parallel side walls I! adapted to support the rollers. The base plate is preferably of heavy steel corrugated as shown at Ilia to add strength and stillness. The side walls are preferably welded to the base plate and each side wall is preferably bent in as shown at Ila, Fig. 3, to provide support for a housing l8 for the tread pin. This housing is preferably a piece of pipe welded into position as shown in Fig. 3. At the opposite side of the shoe spaced bosses l9 consisting of short lengths of pipe are welded to the base plate and to the side wall ll. It will be readily understood that when the track is assembled the box l8 of one shoe lies between the bosses IQ of the adjacent shoe and a tread pin l5 passes through alined openings in the bosses so as to tie adjacent shoes together after the manner of a hinge pin. Qne manner of securing the pins in place is shown in Fig, 3 where an expansible plug 20 engages in notched portions on the inner face of the boss l9 so as'to prevent withdrawal of the pin IS. The shoe is further stiffened by means of a cross brace 2| which is welded to the base plate and to the side walls IT. The shoe is further stifiened by turning up the lip 22 which is adjacent the brace 2|. The bent portion Ila of the side walls is further strengthened and the shoe is stifiened by means of the diagonal braces 23 which are welded to the base plate and to the side walls.

The rollers l3 which occupy an intermediate position between the shoes [4 and the frame 10 are best seen in Fig. 2. This roller structure is symmetrical about the line A--A and therefore one-half only has been shown. It will be understood therefore that there are two rollers l3 each engaging a guide rail l2 and the rollers are rigidly connected together by a, cylindrical member 24 which preferably is a length of pipe welded to a roller at each end. A shaft 25 extends from one side wall I! to the other. This shaft is stepped down at 2511 to provide a seat for the roller bearing 26. The carriage of this bearing is held in position by the nut 21 which is threaded in the outer end of the roller. The outermost end of the roller is further reduced in diameter at 25b and there carries a flinger 28 adapted to prevent the entrance of dirt in any quantity at the open outer face of the nut 21,

Novel means is provided for supporting the very heavy loads transmitted through rollers l3 to the shoes M. At the same time this construction is such that the shafts 25 are easily removed from the track shoes. To this end each side wall II has rigidly secured thereto, as by welding, a semi-cir cular plate member 29 which extends around the lower half only of shaft 25 when shoe l4 engages the ground as shown at the bottom of Fig. l. The inner radius of the member 29 closely fits the shoulder 25b of shaft 25 and provides a large bearing surface for transmitting the crawler frame load through roller l3 and shaft 25 to the shoe 14. The shaft 25 is of such a length that it maybe inserted between the parallel side walls I 1. The shaft is then held in position by. a cap screw 30 at each end. Each cap screw has a shank which passes through a hole ill) in the side wall I! which is of larger diameter than the shank of the cap, screw. The cap screw then has threaded engagement at 3| with the shaft 25. Thus, when the two cap screws 30 are pulled up tight against the washers 32 the shaft 25 is held in position in the shoe. It will be noted that the cap screws merely hold shaft 25. in the proper pos tion while the load is transmitted through shaft 25 and member 29 to the side walls I! of the shoe.

Novel means is provided for lubricating the roller bearing 26. It will be noted that there is a hollow space 33 opposite the end of the cap screw shank. Passageways 34 are drilled in the shaft so that lubricant may travel from space 33 to the space 35 and thus reaci; e bearing 26. The cap screw is provided with a central passageway 30a which communicates at its inner end with-the space 33 and at its outer end is provided with a standard fitting 36 for feeding lubricant to the passageway 30a. Thus lubricant to the fitting 38 under pressure may travel to and be forced through the bearing 26.

Lubricant is held in the space around bearing 26, and dirt is prevented from entering this space, by the novel structure indicated generally at 31. This structure is more fully described and claimed in my copending application Serial No 493,528, filed July 5, 1943, to which reference may be had for a complete description. Suflice it to say here that a ring 38 tightly mounted on shaft 25 carries a composite sealing ring 39 which resiliently engages a flat wearing face on the nut 21.

In Fig. 4 is shown a modified form of track shoe 40 capable of use in an assembly like that shown in Fig. 1. Normally a shaft similar to 25 and a roller performing the function of i3 in the first named modification would be assembled in this shoe but the same are omitted from Fi 4 to clarify,the description.

This shoe has a ground-engaging portion 40a across the center of which is welded a ground gripping bar 40b which also serves to reinforce the shoe at the center. A pair of substantially parallel side walls 400 are welded to the base portion 40a. At one end of the shoe a cross web 40d stiff ns the side walls. Hinge pin construction not shown is provided at the pivot points We so that the shoes may be attached in an endless track.

Referring to Fig. 5, a roller 4| comprising two end roller portions 4la (only one of which is shown) engages a track like that shown at l2 in Figs. 1 and 2. Tapered roller bearings 42 located symmetrically with respect to the center line A serve to journal the roller on the supporting shaft 43. At each end this shaft is provided with a sleeve 44 for a purpose later to be described. Through the medium of the sleeve 44 shown in Fig. 5, the end of the axle is firmly supported in a semi-circular cradle 45 which is rigidly mounted on the shoe side wall 400 as by welding or the like. The form of this cradle is more clearly seen in dot-dash lines in Fig. 4. It will be obvious that the shaft and roller assembly including the sleeve 44 is adapted to be removed and inserted between the parallel side wall portions 400 when the cap screw 46 is absent. As in the first described form of my invention, however, the assembly is completed after the shaft 43 reaches the position of Fig. 5 by inserting the cap screw 46 which is threaded at 46a to enter a like thread in shaft 43.

A look washer 41 keeps this cap screw from backing off.

As in the first described form of my invention, a lubricant passageway 48 is provided in the cap screw communicating with passageway 49 in the shaft so that lubricant may be fed to the space 50 on the inside of the bearing 42. This lubricant works through the bearing past the roller an is prevented from escaping by the seal indicated generally at 5|. This seal also prevents the entranceof dirt to the bearings and is of a known type not requiring further description here.

One difference between the modification of Figs, 4 and 5 and my first described modification is that means is provided for holding the shaft 43 and its connected parts under initial tension pressed into the cradle 45 when the parts are assembled. I find that this insures a firm support hold tolerances so close as to obtain a firm support of shaft 43 in the cradle 45. The means here utilized for obtaining the above mentioned tension is the positioning of the center B of th hole 52 in the side wall portion 400 slightly below (say /e4 of an inch) the center 0 of the are which defines the radially innermost shoulder 45a of the cradle 45. The cap screw 46 is then so constructed that the threads 46a may be well entered into the associated thread in shaft 43 befor the smooth shoulder 46b ofthe cap screw engages in the opening 52. For instance, referring to Fig. 7, the shoulder D is of the same order as the dimension in Fig. 4. As mentioned before, I find that /e4 of an inch fulfills my purpose. It results from this construction that as the screw 46 is drawn finally into the position of Fig. 5, shaft 43 and the associated sleeve 44 are forced downwardly as the shoulder 46b engages in opening 52. This wedges the parts against the cradle 45. It is obvious that the provision of the slight distance E between the centers B and C described in connection with Figs. 4 and 5 could be applied to the device of Fig. 2, where the shaft 25 engages directly against the cradle 26. In other words, the addition of the sleeve 44 in Fig. 5 is not essential to the principle of the wedging action disclosed.

The central portion of Fig. 4 illustrates diagrammatically this construction as applied to Fig. 2 as clearly as would another view. This construction of Fig. 2, using the above-mentioned teaching, would have shaft portion 25b fitting into the cradle 29 in the position exactly analogous to the surface 45a whose center is C. The hole Hb in the shoe side wall I! is in the same position as the hole 52 of Fig. 4 and has the center B slightly below the center C. It results from this construction that when the screw 30 enters the hole I"), the shaft 25 is forced tightly against the cradle 29.

The purpose of the sleeve 44 is to provide takeup in the bearing 42 when necessary. In carrying out this object I provide on the opposite end of shaft 43 (not shown) a sleeve exactly like 44 except that it is not threaded on shaft 43 but instead snugly embraces the shaft. This ring at the opposite end, however, abuts against the cone 42a of the bearing 42 at the other end of the shaft, thus positively locating the cone on the right-hand end of the shaft. Then the sleeve 44, shown in Fig. 5, is turned somewhat further onto the threads 44a'so as to push the cone 42a toward the right as viewed in Fig. 5. The cap screw 46 shown in Fig. 5 is then drawn up tightly so as to draw th wall portion 400 firmly against the left-hand end of sleeve 44 so as to prevent the sleeve backing oif. The outer bearing races 42b at both ends of the shaft fit firmly against corresponding shoulders in the roller 4|. Therefore by taking up on the sleeve 44 shown in Fig. 5, th bearings at both the rightand left-hand ends of shaft 43 are tightened. This is a very simple and easy arrangementfor tightening the roller bearings 42. Milled slots 44b are spaced about the periphery of the sleeve 44 so that a spanner wrench may be utilized to pull up the sleeve 44.

The purpose of the ring 52 of rubber or similar sealing material is to prevent the entrance of dirt at the end of the shaft. This ring is slightly compressed in the annular groove 440 of the sleeve to accomplish this purpose! What I claim is:

1. In the combination of a track shoe and a roller carried thereby, shaft means for supporting said roller, a cradle rigid with said shoe and lying beneath the end of said shaft means, there being an axially extending threaded recess in the end of said shaft means, there being a bolt hole in said shoe substantially alined with said recess, and a bolt snugly fitting said hole and threaded in said recess, the center of said hole being slightly below the center of said recess when said shaft means normally rests on said cradle, whereby when said bolt fully enters said threads said shaft means is wedged against said cradle.

2. A track shoe having a ground-engaging portion and spaced side Walls, a shaft non-rotatably carried by said shoe, a roller rotatably carried by said shaft and adapted for carrying a load, said shaft being of a length to pass into and out of normal position between said side walls and lying wholly between said side walls, means rigid with said shoe supporting said shaft on that side only of said shaft opposite the rollerload, and removable means holding said shaft in position between said side walls, whereby when said last named means is removed said shaft and shoe may be separated at the side of said shaft opposite said shaft supporting means by pulling said shaft out sidewise from between said walls.

3. In the combination of a track shoe and a roller carried thereby, shaft means for supporting said roller, a cradle rigid with the shoe, wedging means for holding said shaft means wedged against said cradle, and said means holding said shaft means assembled in said shoe.

4. In the combination of a track shoe and a roller carried thereby, shaft means for supporting said roller, a. cradle rigid with the shoe, wedging means for holding said shaft means wedged against said cradle, said means holding said shaft means assembled in said shoe, and means passing through said wedging means for feeding lubricant between said shaft means and said roller.

5. In the combination of a track shoe having parallel side walls and a roller-carrying shaft of length insufiicient to fill the space between said walls, a sleeve threaded on the end of said shaft and extending the same sufliciently to fill the space between said walls, a bearing between said shaft having tapered parts adjustable by relative movement axially of said shaft, means holding one of said tapered parts, an inner portion of said sleeve engaging the other of said tapered parts so that screwing said sleeve on said shaft adjusts said bearing, and securing means outside one of said walls and engaging said shaft to hold said shaft in said wall and holding said wall against the outer end of said sleeve, whereby to hold said sleeve in its bearing-adjusting position.

6. The combination of claim 4 including a cradle rigid on said shoe and having an arcuate surface engaging the under side of said sleeve, whereby the larger area of said sleeve transmits load pressure to said cradle.

RAYMOND Q. ARMINGTON.

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

UNITED STATES PATENTS Number Name Date 1,561,996 Perry Nov. 17, 1925 2,206,966 Law July 9, 1940 1,793,190 Philips Feb. 17, 1931 1,362,910 Zoeller et 8.1 Dec. 21, 1920 1,628,220 Berg May 10, 1927

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