US1942907A - Draft gear - Google Patents

Description

H. L. SPENCE Jan. 9, 1934.

DRAFT GEAR Filed Deo. 51, 1930 2 Sheets-Sheet 2 H/fl/ mmlllml Patented Jan. 9, 1934 DRAFT Hubert L. Spence, East Cleveland, Ohio,

GEAR

assigner to National malleable & Steel Castings Company, Cleveland, ho,

a corporation of Ohio Application December 31, 1930 Serial No. 505,759

6 Claims.

lIhis invention is concerned with the provision of a novel and improved railway draft gear. The invention includes a novel arrangement and relationship of springs for cooperating with wedgng and friction elements, whereby not only is a high frictional and spring capacity attained but also wear upon the springs and housing is obviated. A more specific feature of the invention comprises the provision of spring seating or follower means cooperating with a group of springs for enabling the latter to oppose movement of friction shoes and at the same time, through its cooperation with the central spring of the group, preventing engagement of others of said springs with the wall of the draft gear case. Other features of the invention will be hereinafter deu scribed and claimed.

In the accompanying drawings:

Fig. 1 is a longitudinal vertical sectional View of a draft gear embodying my invention, said view being taken on line 1 1 of Fig. 3.

Fig. 2 is a horizontal sectional View thereof taken on line 2 2 of sig. 4.

Fig. 3 is a transverse vertical section taken on line 3-3 0f Fig. 1.

Fig. 4 is a transverse vertical section on line 4-4 or" Fie. 2.

Fig. 5 is a detail View in front elevation of a spring follower.

Fig. 6 is a detail View, partly in plan and partly in horizontal section, of said follower, and

Fig. I is a detail view in vertical section on line 7 7 of Fig. 5.

Referring to the drawings, the gear comprises a case 2, preferably rectangular in form, in opposite walls 3 of which are seated the friction members 4, each of which ispreferably a rectangular block having at its inner end a lateral projection 5. In each wall 3 is a recess 6 in which the projection 5 of the associated friction member l is seated. To resist the inward thrust of the friction members 4, the case 2 at the rear of the recesses 6 has abutments 6 against which the members 4 bear at their rear ends, and said abutments 6' are braced by ribs 7 which extend back to and are merged into the rear end 8 of the case.

On opposite sides of each of the friction members 4 and in frictional engagement therewith are arranged friction shoes 9, two friction members and four shoes being provided. The inclined forward faces of the shoes 9 are engaged by correspondingly inclined faces 10 of a wedge member 11. Each shoe face has also an inclined recess 12 into which nts a correspondingly inclined rib or ange 13 on the wedge 11 for the purpose of maintaining the shoes and wedging faces in alignment and of preventing the shoes 9 from working laterally over to and abrading the sides of the case 2.

Mounted centrally within the case 2 and ex- 5o tending along the longitudinal axis thereof is a coil spring 14, which engages the rear wall 8 of the case 2 at one end and at its other end engages a pair of spring seat members or followers l5, 15, each oi' which spring seat members engages the 65 rear faces 16 of the projections 17 of a pair of the shoes 9. Each spring seat member extends from a shoe cooperating with one of the friction inembers 4 to a shoe cooperating with the other of said friction members. Surrounding the central spring 14.- aforesaid are four springs 18, one for each shoe i?, and positioned in the respective corner portions of the case, as shown in Fig. 3. Each of said springs 18 bears at its rear end against the end wall 8. At their forward ends, two of said springs engage one of the spring seat members 15 and the other two of said springs engage the other of said spring seat members.

Each of the spring seat members 15 is provided with a pair of rearwardly extending projections or bosses 19 which extend into the coils of the associated springs 18 and thereby maintain said coils in a definite relation to the spring seat member. I further construct each of said spring seat members with a built out or extended portion 20 having a lip or projection 21 which eX- tends into the interior of the coil spring 14. Said projection 21 is curved, as shown, to conform with the curvature of said coil. Through the engagement of the projections 21 of the respective 90 spring seat members 15 with the interior of the coil of spring 1li said seat members are prevented from shifting to such extent as to permit the springs 13 to engage the walls of the case 2. It will be une erstood that the dimensions of the parts are such that these results will be accompiished. In other words through the spring seat members and their cooperation with the central spring 141 the springs 18 are retained in a denite relation to said central spring and are maintained out of engagement with the walls of the case 2; and I thus obviate the possibility of objectionable wear between said walls and said springs 18. Furthermore, in the construction i1- lustrated, the spring 14 is maintained against 195 undesired lateral displacement by engagement with projection 21, which in turn engages bolt 22. Also, the extended bearing 20 which I provide between the seat members 15 and the central spring 110 14 minimizes wear between that spring and said members.

The case 2 and wedge 1l are maintained in assembled relation by a bolt 22, which is engaged at its rear end with an opening in the wall 8 of the case and at its forward end extends through an opening in a central projection 23 of the wedge. A nut 24 is threaded on said bolt within the recessed portion 25 of said projection. The spring seat members or followers l5 are cut away or notched as shown at 26 for accommodating the bolt 22. Said spring seat members are also provided on their front surfaces with upper and lower reinforcing ribs 27, 28, as shown.

It will be seen that compression of the gear is resisted by the springs 14 and 18, and by the friction generated between the shoes 9 and the associated friction members li. Said shoes, under the influence of the wedge surfaces 10 and the action of the springs 14 and 18, are maintained in firm frictional engagement with the friction members during the compression of the gear. The amount of friction developed between the shoes and friction members is dependent on the angle of inclination of the sides or faces of the friction members to the longitudinal axis of the gear. 'Ihe faces of said friction members may be inclined at any suitable angle or may be parallel to said longitudinal axis of the gear. When the pressure on the gear abates the parts are returned to their normal positions by the action of the various springs.

The extent of movement of the wedge with respect to the case is such that just before the springs go solid the peripheral flange 29 of the wedge will engage the front end of the case.

While I have shown the projections 5 of the friction members in firm engagement with the openings 6, a limited amount of clearance may be provided between said openings and projections. In this way the initial compression of the gear may be opposed simply by the springs 14 and 18 and further compression thereof both by said springs and by the friction developed between the shoes and friction members. The extent of preliminary spring action may be varied by varying the amount of said clearance, and the capacity of the springs.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features Shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

I claim:

1. In a draft gear, a case, friction members within said case; a plurality of pairs of friction shoes, each of said pairs being in frictional engagement with a corresponding one of said members; a plurality of springs, one for each of said shoes for resisting movement of said shoes, said springs extending longitudinally of said case adjacent the walls thereof, a pair of spring seat members, one of which is interposed between Icertain of said shoes and the corresponding springs, and the other of which is interposed between others of said shoes and the springs corresponding thereto, each of said spring seat members having projections engaged by the associated springs for maintaining the latter in a given relation to the spring seat members; a spring positioned centrally in said case and engaging both seat members; and projections on said seat members extending within the coil of the last mentioned spring.

2. In a draft gear, a case, cushioning means comprising springs extending substantially the length of said case, certain of said springs extending adjacent the side walls of the case, and another of said springs being positioned in a central portion of the case, friction elements mounted in said case in spaces between said springs, shoes engaging said friction elements, and spring seating means interposed between said shoes and springs, said spring seating means having means cooperating with said spring for maintaining all of said springs in a given relation to each other.

3. In a draft gear, a case, friction means in said case comprising friction shoes, a wedge engaging said shoes, springs extending longitudinally in said case adjacent the walls thereof and resisting movement of said shoes, a plurality of spring seat members each interposed between respective ones of said shoes and the corresponding springs, a spring positioned centrally in said case and engaging said spring seat members for resisting movement of said shoes, and a retaining bolt engaging said wedge and said case and extending through the interior of the coil of said centrally positioned spring and between said spring seat members, each of said spring seat members interlocking with said central spring and one of said other springs to maintain said springs in proper spaced relation.

1. In a draft gear, a rectangular case, a spring in each corner of said case, a member engaging an end of each of a pair of said springs, a second member engaging an end of each of another pair of said springs, a spring positioned centrally of said case and means on said members engaged with said central spring for maintaining said pairs of springs in a given relation to eachother.

5. In a draft gear, a case, a plurality of pairs of springs in said case, means joining the springs of one pair and separate means joining the springs of another pair of said springs for holding the springs in each pair a given distance apart, a central spring positioned between said pairs of springs, and means on said joining means engaging said` central spring for preventing separation of said pairs of springs.

6. In a draft gear, a case, friction means in said case comprising friction shoes, a wedge engaging said shoes, springs extending longitudinally in said case adjacent the walls thereof and resisting movement of said shoes, a plurality of spring seat members each interposed between respective ones of said shoes and the corresponding springs, and a spring positioned centrally in said case and engaging said spring seat members for resisting movement of said shoes, each of said spring seat members interlocking with said central spring and one of said other springs to maintain said springs in proper spaced relation.

HUBERT L. SPENCE.

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