US2205066A - Draft gear - Google Patents

Description

June 18, 1940. c, PlERCE AL 2,205,066

DRAFT GEAR Filed Feb. 2, 1939 3 Sheets-Sheet 1 ATTORNEY.

R. C. PIERCE ET AL.

DRAFT GEAR Filed Feb. 2, 1939 June 18, 1940.

3 Sheets-Sheet 2 ATTQRNEY.

June 13, 1940- I R. c. PIERCE ET AL DRAFT GEAR Filed Feb. 2, 1939 3 Sheets-Sheet 5 7720 CPgs/te,

rzd P Jazz/2e,

ATTORNEY.

Patented June 18, 1940 UNITD STATES PATENT OFFHCE f Raymond C. Pierce, Chicago, 11]., and Edmund P.

Kinne, Alliance, Ohio, assignors, by mesne assignments, to said Pierce Application February. 2, 1939, Serial No. 254,134

' 40 Claims. (01. 2'1e-34 This application is a contiiIuatiOmin-part of our copending application, Draft gear, Serial No. 214,410, filed in the United States Patent Office June 18, 1938. I

Our invention relates to a shock absorbing mechanism for railway cars of the form generally designated a draftgear of the barrel .type where in the mechanism consists of an outer housing of generally cylindrical forin with a compression spring enclosed therein and an outwardly flaring open end wherein is received what issometirnes known as a clutch mechanism.

Generally speaking, the object of our invention is to devise such a structure wherein substantially greater friction absorbing capacity will be developed than is required under the present standards, thus providing a shocl; absorbing mechanism capable of withstanding the substantially heavier shocks resulting from increased train loads or higher speeds. v

A further and more definite object of our invention is to devise a draft gear of the barrel type wherein a plurality of friction shoeswill be fitted within'the barrel and accommodated for engagement with the inner and outer'followers by insertsof a form peculiarly adapted to facilitate accurate seating of parts without great refinement of manufacturing processes.

In ordinary gears of this clutch type the frictional resistance obtained is relative to the wedging angle with which the follower wedge engages the shoes. In such gears increase'of this angle beyond the critical point is strictly limited by the tendency of the gear to stick. In, our novel gear this wedging angle may be increased to a much greater extent inasmuch as our novel construction offsets the sticking tendency otherwise present. Among the objects of our invention, therefore, is the purpose to design a clutch type gear which will permit the development of substan tially high friction absorbing capacity while at the same time permitting free release.

Another object of our invention is to devise a draft gear which will develop a relatively high capacity in the initial portion of the stroke. The A. A. R. standard requires that 25 percent of the capacity be developed in the first half of the stroke. Our purpose is to develop a much greater portion of the capacity in the first half of the stroke, thus enabling us to avoid excessive capacities at the end of the stroke and shocks resultant therefrom.

Our invention also contemplates such a draft gear as that above described wherein the spring cap is integrally formed with the inner follower wedge and wherein said follower wedge is interlocked with the several shoes in such manner as to obviate relative rotation therebetween.

Our invention also comprehends such a gear;

as that above described wherein the inner fol- 5 lower wedge has abutment with the several serts seated against the respective shoes and transmits the spring reactions directly to said inserts through which said reactionsmay be further carried to the respective shoes and to the 10 outer follower wedge.

Another object of our invention is. to devise a truss type draft gear wherein forces from the outer follower wedge will-be transmited to a series of shoes through a series of inserts, one in- 15 sert being associated with each shoe, and wherein the engaging surfaces between the outer follower wedge and the insert will be of cylindrical form with a relatively long radius and the,

engaging surfaces between each insert and the adjacent shoe will likewise be a cylindrical surface with a relatively short radius.

A further object of our invention is to design a gear as abovedescribed wherein the inserts;

of the several shoes will maintain. a constant bearing against the inner follower wedge under all conditions of normal operation of the gear.

Figure l is a longitudinal sectional view of our novel form of draft gear, the section being taken substantially in the horizontal plane bisecting the gear longitudinally and as indicated by the line l--l of Figure 2;

Figure 2 is an end elevation, partly in section,

the section at the lower portion of the figure heing taken in the transverse plane substantially as indicated by the line 2-2 of Figure 1 and the section at the upper left of the figure being taken substantially in the transverse plane indicated by the lineAA of Figure 1;

Figure 3 is a plan view of the spring cap, 4

the view being taken from the outer face thereof;

Figure 4 is a side elevation of the spring cap or inner follower wedge;

Figure 5 is a plan View the view being taken from the inner face thereof; Figure 6 is an end elevation of the shoe, the View being taken from the outer end;

Figure 7 is a sectional view in a plane bisecting the shoe through its length and substantially in the plane indicated by the line 1-7 of Figure 5;

Figure 8 is a sectional view taken diagonally through the friction shoe and substantially in the plane indicated by the line 88 of Figure '7;

of one of the shoes, 45

Figure 9 is a plan view of the outer follower Wedge, the View being taken from the inner face thereof;

Figure 10 is a side elevation of the outer fol lower wedge;

Figure 11 is a plan view of the insert, the view being taken from the outer face thereof;

Figure 12 is an end elevation of the insert, the view being taken from the upper end;

Figure 13 is a side elevation of the insert;

Figure 14 is a fragmentary view corresponding in general to the View shown in Figure 1 of a modified form of our novel draft gear, the view being taken substantially in the horizontal plane bisecting the gear longitudinally and as indicated by the line l4-i4 of Figure 15;

Figure 15 is an end elevation corresponding in general to the view of the previous modification shown in Figure 2 and partly in section, the section at the bottom of the figure being taken in the transverse plane substantially as indicated by the line [5-45 of Figure 14, and the section at the left of the figure being taken substantially in the transverse plane indicated by the line B-B of Figure 14; and

Figure 16 is a longitudinal section through the tongue and groove engaging surfaces of the inner spring follower and one of the shoes, the section being taken substantially as indicated by the line l6-l6 of Figure 14.

Describing our invention in more detail, the housing 2 is of a form more particularly described and shown in United States Letters Patent No. 2,160,417, issued May 30, 1939, in the name of William C. Hedgcock, wherein Figure 8 shows the particular form of housing here used. The housing 2 is of generally cylindrical form having the base 4 and the side walls 6 and the inner surface at the open end of the housing is flared outwardly in the well known manner as best seen at 8 (Figure 1). Centrally formed on the inner face of the base 4 is the hollow stud ID, the walls of which define the cavity I2 within which may be received the head 14 of the retaining bolt 16, the opposite end of said bolt receiving the threaded nut is. Within the housing is positioned the large outer compression spring 20 seated at its inner end against the base 4 and retained in position by the stud ID. The auxiliary spring or inner compression spring 22 is seated at its inner end against the inner face of the stud l and the outer ends of both springs 20 and. 22 are seated as at 24 and 26 against the spring cap 23, the inner spring being seated in a shallow cavity 28 formed on the inner face of the spring cap as best seen in Figure 1.

In addition to the combination spring cap and inner follower wedge 23, the clutch mechanism comprises three shoes 30, 30 symmetrically arranged around the inner face of the housing, an insert 32 associated with each shoe 30 and the outer follower wedge 34. It may be observed that the reacting force is delivered from the compression springs 20 and 22 through the inner follower 23 to the inserts 32 and thence are distributed against the several shoes 30, 30 arranged around the periphery of the housing and to the outer follower wedge 34. The shoes 30, 30 have no engagement with either follower wedge except at its inner end each shoe is interlocked with the inner follower wedge 23 by a tongue and groove fit as at 36 (Figure 1) best understood from a consideration of the detail showings of these parts in Figures 3, 4, and 7.

The arrangement of the shoes around the housing is best seen in Figure 2 where it may be observed that each shoe 30 has a generally V-shaped outer face fitted into a surface of complementary shape formed on the inner periphery of the housing. The housing is thus hexagonal in section with each shoe occupying substantially one-third of the periphery or some thing less than one hundred twenty degrees. The manner in which the various parts of the clutch mechanism seat against each other will be best understood by a consideration of the detail structures of these parts.

The form of the combination spring cap and inner follower wedge is shown in Figures 3 and 4. It may be observed that the base 38 is generally hexagonal having on its inner face the beforementioned shallow circular cavity 28 serving as positioning means for the inner spring 22 and having on its outer face the large boss 40 with the central opening 42 along the axis of the gear for reception of the retaining bolt I6. The boss 49 is of generally cylindrical form presenting on its outer surface the three diagonally arranged fiat faces 44, 44 symmetrically arranged around said boss and serving as abutments against which may be seated the inner ends of the inserts 32, 32 as at 46 (Figure 1). Also symmetrically arranged around the base 38 are the slightly raised portions or tongues 48, 48 aligned respectively with the faces 44, 44, said tongues being received in corresponding grooves 50, 50 (Figure 5) formed on the inner edges of the shoes 30, 30 and serving to interlock said shoes with said inner follower wedge in a manner to prevent their relative rotation.

The detail structure of each shoe is shown in Figures 5 to 8, inclusive, and consists in general of a solid body of metal, V-shaped in cross-section and generally rectangular in plan with a slightly greater width at its outer end than at its inner in order to accommodate the shoe structure to the flaring open end of the barrel or housing 2. The shoe has the V-shaped outer face with an included angle of approximately one hundred twenty degrees between the two portions thereof,

the several shoes thus being accommodated in the complementary seats formed on the inner face of the open end of the barrel. Each shoe has on its inner face the cylindrical surface 52 defining a relative shallow cavity designed to accommodate the complementary surfaces 54 (Figure 12) formed on the outer face of the insert 56. The upper extremity of the shallow insert receiving cavity is defined by the shoulder 58 at the upper end of the shoe. The back wall of the shoe is extended beyond the heavy central body portion 60 (Figure '7) in the projection 62, and transversely across the bottom of said body portion 60 at the middle thereof is formed the previously mentioned shallow groove 50 for the reception of the complementary tongue 48 formed on the outer face of the spring cap or inner follower wedge.

The inserts 56, 56 are of identical form, each being a solid body of metal of generally rec tangular form and greater width than length. having at its inner end the flat surface 62 for abutment against a face 44 of the inner follower wedge; presenting also an outer cylindrical surface 54 complementary in form to the shoe surface 52 against which it is seated as previously described and having also a flat inner face 64 for abutment against the outer follower wedge. When the parts are assembled, each insert 32 has a clearance from the shoulder 58 at the outer iegcosgoce end of theassociated "shoe as'best seen at 66 (Figure 1) The outer follower wedge 34 is of cup -like' form as shown in Figures 9-and l0,"the"o,uter' portion tional follower block, the'outer perimeter of said portion being defined bythe annular fiangel extending beyond the annular walls-H. 'II. Cen trally formed in the outer face of'this'follower wedge is the cavity 12' within which may be received the projecting end of the retaining bolt It with its associated threaded nut,-said bolt'eX- tending through the opening 'Ifi'cen'trally formed in the follower wedge. At its inner end this follower wedge presents the'threefl'at faces 16.16 symmetrically arranged there-around, each of said faces being designed to abut'the inner face it of the associated insert, the engagement therebetween being best shown at I8 (Figure l) We have discovered that the length of theradius determining the cylindrical surface on the back of each insert 32 and on the inner face of each shoe 30 is determinative of the rotational stability of the insert under operating conditions; in other words, to preventrotation'of the insert with respect to the associated shoeagainst which it is seated, it is necessary that the radiusfrom which the before mentioned cylindrical surface is described be less than the distance X (Figure 1) lying in a plane bisecting said cylindrical surface normally thereto, and intersecting the axis of the gear.

It may be noted further (Figures 1 and 13) that the included angle M should be less'than ninety degrees for best operation 'of thisgear and likewise the included angle N should'be equal to or greater than a right angle.

The modification shown in Figures l4and 15 differs from that previously described in that the engaging surfaces between the outer follower wedge and the inserts are of cylindrical form instead of flat. The housing I02 is like that of the previous modification having aboutits periphery at the open end the inner friction surfaces generally V-shaped against which are' seated the shoes tilt, IM and associated with each shoe is an insert I06, the insert having engagement with the shoe along the cylindrical surface 108 similar to that of. the previous modification. The opposite surface of each insert engaging the follower H2 as indicated at H0 in this modification is a shallow cylindrical surface instead of a flat surface as in the previous modification. The charactor of this shallow cylindrical surface andits relative curvature as compared with the curvature at the opposite side of the insert as shown at its is best seen from a consideration ofthe sectional View at the bottom of Figure 15. The follower I H? is otherwise similar to that of'the previous modification, having the outwardly facing cavity H4 receiving the retaining'bolt and nut assembly H6, said bolt extending'through the centrally formed opening H8 in the spring cap follower 20. The said spring cap follower has a flat face abutment as at I22 with the inwardly di rected bottom surface of each insert I and the spring cap follower likewise has a tongue and groove engagement with each shoe I04, the groove indicated at I24 and the tongue at IZt'in the view shown in Figure 16, said tongue and groove engagement being similar to that described for the previous modification. The inner face of the spring cap follower abuts the large compression spring I28 on an annular surface about its seat I30.

the shoes. squeezed between the outer follower and the "periphery as indicated at I30 and likewise abuts *the'relatively small compression: spring I32 asaat I34 on the'seat offset from thebefore'mentioned The lengthof the radius for the cylindrical surface on the back of each insert I06 is determined '-as described for the previous modification and. the radius at the opposite side of the insert where it engages a complementary surface on the'outer follower is of much greater length as clearly seen from a consideration of sections therethrough as indicated at I08 and H0 (Figure The radius defining the surface at H0 shouldbe such as to produce a minimumof curvature on these surfaces, but to accomplish the desired results" must be cylindrical as distinguished from flat.

Our theory of the method of operation ofour novelgear is as follows:

'When the parts are in released position as shown in Figure l the outward pressure of tha springsis effective to retain the clutch parts tightly wedged in position with the shoes firmly urged against the barrel and the inserts tightly wedged between the shoes and the inner and cute er followers. 'Because of the relatively sharp angle between the shoes and the inserts the outward pressure of the shoes against the barrel is greater than would ordinarily be possible in a clutch type gear. When impact is received against the outer wedge follower, the clutch parts are forced into the housing and because the Wedging surfaces 8 of the housing are set at a small angle with respect to the axis of the gear the shoes are forced closer together.

Elasticity of the parts may permit a small amount of inward motion before the clutch parts move relative ,to one another but as such relative movement begins, other members of the clutch assembly move into the barrel more rapidly than the wedge follower. due to the before mentioned axial movement of At the same time the insertsare shoes due to the said axial movement of the shoes, and the inner follower is thus moved inwardly a.

greater distance. than the outer follower travelsl' This sliding action as described between the various parts increases the gear capacity.

When pressure is released from the outer wedge follower at the end of the compression movement.

'the'outer wedge follower promptly frees itself from the inserts because of the relatively fiat angles between said outer wedge follower and said inserts. With the release of the outer wedge follower the other parts are also free to return to the normal released position under the action of the compression spring.

It should be noted that the unusually high capacity of our novel gear is largely due to the fact that it permits the use of unusually acute angles between the inserts and the shoes while" attaining desirable release characteristics by the "use of relatively fiat angles between the outer wedge follower and the inserts.

This arrangement of said angles permits the compression spring to function efficiently in tightly wedging" the clutch parts together after each stroke so that the parts are ready for the next. impact. "This results in a gear which develops a rela- "tively great capacity in the initial portion of the stroke and enables us to avoid excessive ca- 'pacity at the end of the stroke otherwise necessary in order to meet required standards. Such excessive capacity at the end of the 'stroke'develops shocks harmful to the car structure and ladin'g.

It is to be understood that we do not wish to be limited by the exact embodiments of the device shown which are merely by way of illustration and not limitation as various and other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

We claim:

1. In a friction absorbing device, a housing, a compression spring therein, clutch means seated in the open end of said housing, and a retaining bolt, said clutch means comprising inner and outer follower wedges, a plurality of shoes symmetrically arranged around the inner circumference of said open end and aligning means associated with each shoe and having diagonally arranged cylindrical face engagement therewith and having fiat face engagement with each of said wedges, said shoes being free of engagement with one of said wedges and having interlocking engagement with the other, said interlocking engagement comprising a transverse slot adjacent the inner edge of each shoe, and a plurality of means on said inner wedge receivable in said respective slots thereby preventing relative rotation of said shoes and said wedge.

2. In a friction draft gear of the barrel type, a housing having a flaring open end, a compression spring, clutch means, and a retaining bolt, said clutch means comprising inner and outer follower wedges, a plurality of shoes symmetrically arranged around the inner periphery of said open end, and an insert associated with each shoe for transmission of thrusts between said shoe and said inner and outer wedges, said insert having fiat face engagement with each of said wedges and having diagonally arranged cylindrical face engagement with the associated shoe, the cylindrical face of said insert having a radius less than that of the line defined by the intersection of longitudinal and transverse planes bisecting said insert and extending from said cylindrical face to the longitudinal axis of said gear.

3. In a friction draft gear of the barrel type, a housing having a flaring open end, a compression spring, clutch means, and a retaining bolt, said clutch means comprising inner and outer follower wedges, a plurality of shoes symmetrically arranged around the inner periphery of said open end, and an insert associated with each shoe for transmission of thrusts between said shoe and said inner and outer wedges, said insert having diagonally arranged cylindrical face engagement with said shoe, said cylindrical face having a radius of less length than that of a line defined by planes bisecting said insert transversely and longitudinally thereof and extending from said cylindrical surface to the longitudinal axis of said gear.

4. In a friction absorbing device, a housing having an open end, a compression spring, clutch means seated in said open end, and a retaining bolt, said clutch means comprising inner and outer follower wedges, a series of friction shoes seated against said housing, and thrust means associated with each of said shoes, said thrust means having diagonal cylindrical face engagement with the associated shoe and having fiat face engagement with each of said wedges along planes defining acute angles with said cylindrical face, said inner wedge having means interlocked with each of said shoes to prevent relative rotation of said wedge and said shoes.

5. In a friction absorbing device, a housing, a compression spring therein, clutch means seated in the open end of said housing, and a retaining bolt, said clutch means comprising inner and outer follower wedges, a plurality of shoes symmetrically arranged around the inner circum ference of said open end, and aligning means associated with each shoe and having diagonal cylindrical face engagement therewith and having flat face engagement with each of said wedges, said shoes being free of engagement with one of said wedges and having interlocking engagement with the other of said wedges to prevent relative rotation thereof.

6. In a friction absorbing device, a housing having an open end, a compression spring, a clutch mechanism seated in said open end, and a retaining bolt, said mechanism comprising inner and outer wedges, a plurality of symmetrically arranged friction shoes, and thrust means associated with each of said shoes in the form of rectangular means of greater width than length, said means having diagonal cylindrical face engagement with the associated shoe and diagonally arranged fiat face engagement with each of said wedges, said flat faces defining an included angle equal to or greater than ninety degrees.

'7. In a friction absorbing device, a housing having an open end, a compression spring, a clutch mechanism seated in said open end, and a retaining bolt, said mechanism comprising inner and outer wedges, a plurality of symmetrically arranged friction shoes, and thrust means associated with each of said shoes in the form of rectangular means of greater width than length, said means having diagonally arranged cylindrical face engagement with the associated shoe, diagonally arranged cylindrical face engagement with one of said wedges, and diagonally arranged fiat face engagement with the other of said wedges.

8. In a friction absorbing device, a housing having an open end, a compression spring, clutch means seated in said open end, and a retaining bolt, said. clutch means comprising inner and outer follower wedges, a series of complementary friction shoes seated against said housing, and thrust means associated with each of said shoes, said thrust means having diagonal cylindrical face engagement with the associated shoe and having fiat face engagement with each of said wedges along planes defining acute angles with the cylindrical face of said thrust means.

9. In a friction absorbing device, a housing having an open end, a compression spring, a clutch mechanism seated in said open end, and a retaining bolt, said mechanism comprising inner and outer Wedges, a plurality of symmetrically arranged friction shoes, and thrust means associated with each of said shoes in the form of rectangular means of greater width than length, said means having diagonally arranged cylindrical face engagement with the associated shoe and with one of said wedges, and flat face engagement with the other of said wedges, said means tapering from a relatively thick lower end toward the upper end thereof.

10. In a draft gear of the barrel type, a housing having a flaring open end of generally hexagonal cross section, a compression spring housed therein, friction means, and a retaining bolt, said friction means comprising an inner follower, an outer follower, three friction shoes having V-shaped outer faces symmetrically seated last mentioned follower against said flaring open end, and aligning means associated with each shoe, said aligning means having diagonally arranged cylindrical face engagement with said shoe and with said outer follower, and flat face engagement with said inner follower.

11. In a friction absorbing device, a housing having an open end, a compression spring, clutch means seated in said open end, and a retaining bolt, said clutch means comprising inner and outer follower wedges, a series of complementary friction shoes seated against said housing, and thrust means associated with each shoe and having diagonal cylindrical face engagement therewith and with said outer follower wedge, said thrust means having flat face engagement with said inner wedge in a plane defining an acute angle with the cylindrical facethereof.

12. In a friction absorbing device, a housing having an open end, a compression spring, a clutch mechanism seated in said open end, and retaining bolt, said mechanism comprising inner and outer wedges, a plurality of symmetrically arranged friction shoes, and thrust means associated with each shoe and having diagonal flat lace engagement with said inner wedge and diagonal cylindrical face engagement with said outer wedge and with each of said shoes, each of said shoes having adjacent its inner edge means engaging said inner wedge to prevent relative rotation. thereof.

13. In a friction absorbing device, a housing having an open end, a compression spring, a clutch mechanism seated in said open end, and a retaining bolt, said mechanism comprising inner and outer wedges, a plurality of symmetrically arranged friction shoes, and thrust means associated with each shoe and having diagonal fiat face engagement with said inner wedge and diagonal cylindrical face engagement with said outer wedge and with the associated shoe, said cylindrical surfaces being defined by relatively long and short radii respectively.

14.. In a friction absorbing device, a housing having an open end, a compression spring therein, clutch means seated in said open end, and a retaining bolt, said clutch means comprising inner and outer wedge followers, a plurality of friction shoes, and thrust means associated with each of said shoes and having diagonal cylindrical face engagement therewith and with one of said followers, each of said thrust means having flat face engagement with the other of said followers, said shoes having means engaging said to prevent relative rotation thereof.

15. In a friction absorbing device, a housing, a compression spring therein, clutch means seated in the open end of said housing, and a retaining bolt, said clutch means comprising inner and outer follower wedges, a plurality of shoes'symmetrically arranged around the inner circumference of said open end, and aligning means associated with each shoe and having diagonal cylindrical face engagement therewithv and with said outer wedge, each of said aligning means having fiat face engagement with said inner follower and means on said inner follower engaging each shoe to prevent relative rotation thereof.

4 around said housing, inner and outer'follower wedges, and aligning means associated with each shoe and having diagonal cylindrical face engagement therewith and with one of said wedges and having flat face engagement with the other of said wedges, said other wedge having means engaging each of said shoes to prevent relative rotation thereof, certain of said cylindrical faces being defined by a relatively long radius as compared with others thereof.

17. In a friction draft gear of the barrel type, a housing having an open end, a compression spring, clutch means comprising inner and outer followerwedges, a plurality of shoes symmetrically arranged within said open end, and thrust means associated with each shoe and having fiat face engagement with said inner wedge and cylindrical face engagement with said outer wedge and with the associated shoe, said cylindrical engagement between the thrust means and shoe having a relatively short radius as compared with said other cylindrical engagement, each of said shoes having thrust engagement at spaced areas with said inner Wedge along flat surfaces at right angles to the axis of said gear.

18. In afriction draft gear of the barrel type, a housing having an open end, a compression spring, clutch means comprising inner and outer follower wedges, a plurality of shoes symmetrically arranged within said open end, and thrust means associated with each shoe and having diagonal flat face engagement with one of said wedges and cylindrical face engagement with the other thereof and with the associated shoe, said shoe and wedge cylindrical surfaces having relatively short and long radii respectively, each of said shoes having thrust engagement at spaced areas with said inner wedge along fiat surfaces at right angles to the axis of said gear.

19. In a draft gear, a housing having a flaring open end, a compression spring therein, friction means, anda securing bolt, said friction means comprising inner and outer follower wedges, a plurality of friction shoes symmetrically seated against said flaring open end, and means associated with each shoe and having diagonal cylindrical face engagement therewith, said means having diagonal flat face engagement with each of said wedges along planes defining acute angles with said cylindrical faces.

20. In a friction gear of the barrel type, a housing, a compression spring, a clutch mechanism, and a retaining bolt, said clutch mechanism comprising a series of shoes symmetrically arranged around said housing, inner and outer follower wedges, and aligning means associated with each shoe and having fiat face engagement with one of said wedges and cylindrical face engagement with the other wedge and with the associated shoe, said shoe cylindrical face having a relatively short radius as compared with said wedge cylindrical face, each of said shoes having thrust engagement at spaced areas with said inner wedge along flat surfaces at right angles to v the axis of said gear.

21. In a draft gear of barrel type, a housing having an open friction end, a compression spring, a clutch means comprising inner and outer follower wedges, a plurality of shoes symmetrically arranged within said open end, and thrust means abutting each shoe and extending between said wedges for thrust engagement therewith, each of said shoes having thrust abutment with the adjacent thrust means and one of said wedges, one of said thrust surfaces being along a diagonal cylindrical surface.

22. In a friction draft gear of the barrel type, a housing having a friction end, a plurality of shoes symmetrically seated therearound, a compression spring, inner and outer follower wedges, and thrust means associated with each shoe and extending between said wedges to transmit thrust therefrom to the associated shoes, each of said shoes also having thrust engagement with one of said wedges on a plurality of spaced areas along flat surfaces at right angles to the axis of said gear.

23. In a friction draft gear of the barrel type, a housing having a friction end, a plurality of shoes symmetrically seated therearound, a compression spring, inner and outer follower wedges, thrust means associated with each shoe and. extending between said wedges to transmit thrust therefrom to the associated shoes, each of said shoes also having thrust engagement with one of said wedges on a plurality of spaced areas along flat surfaces at right angles to the axis of said gear, and means on said shoes engageable with means on one of said wedges to limit relative rotation thereof.

24. In a draft gear, a housing having an open friction end, a compression spring, a clutch means seated in said friction end and comprising a plurality of shoes seated around said friction end, inner and outer wedge followers, and independent thrust means extending between said wedge followers and in abutment with said shoes respectively, each of said shoes also having thrust engagement with one of said wedges on a plurality of spaced areas along flat surfaces at right angles to the axis of said gear.

25. In a draft gear, a housing having an open friction end, a compression spring, a clutch means seated on said friction end and comprising a plurality of shoes seated around said friction end, inner and outer wedge followers, independent thrust means extending between said wedge followers and in abutment with said shoes respectively, each of said shoes also having thrust engagement with one of said wedges on a plurality of spaced areas along flat surfaces at right angles to the axis of said gear, and means on each of said shoes engageable with means on one of said followers to limit relative rotation thereof.

26. In a draft gear of barrel type, a housing having an open end with tapering friction surfaces symmetrically arranged therearound, a compression spring and clutch mechanism comprising a plurality of shoes seated against said friction surfaces, inner and outer wedge followers, and a thrust member extending between said followers for each shoe and transmitting thrusts from said followers to said shoe, each of said shoes also having thrust engagement with one of said wedges on a plurality of spaced areas along flat surfaces at right angles to the axis of said gear.

27. In a draft gear of barrel type, a housing having an open end with tapering friction surfaces symmetrically arranged therearound, a compression spring, a clutch mechanism comprising a plurality. of shoes seated against said friction surfaces, inner and outer wedge followers, a thrust member extending between said followers for each shoe and transmitting thrusts from said followers to said shoe, each of said shoes also having thrust engagement with one of said wedges on a plurality of spaced areas along flat surfaces at right angles to the axis of said gear, and means on each of said shoes overlapping means on one of said followers to limit relative rotation thereof.

28. In a draft gear, a barrel having a friction end, a compression spring therein, and clutch mechanism comprising shoes symmetrically seated around said end, inner and outer follower wedges, thrust members extending between said wedges for transmitting thrust therefrom to said shoes respectively, the engaging surfaces between said thrust means and said shoes being of diagonal cylindrical form.

29. In a draft gear, a barrel having a friction end, a compression spring therein, and clutch mechanism comprising shoes symmetrically seated around said end, inner and outer follower wedges, thrust members extending between said wedges for transmitting thrust therefrom to said shoes respectively, the engaging surfaces between said thrust means and said shoes being of diagonal cylindrical form, and means on each of said shoes engageable with means on one of said followers to limit relative rotation thereof.

30. In a draft gear, a barrel having a friction end, a compression spring therein, and clutch mechanism comprising shoes symmetrically seated around said end, inner and outer follower wedges, thrust members extending between said wedges for transmitting thrust therefrom to said shoes respectively, each of said thrust members having diagonal flat face engagement with one of said wedges and diagonal cylindrical face engagement with the other thereof, one of said wedges having thrust engagement with each of said shoes on a plurality of spaced areas.

31. In a draft gear, a barrel having a friction end, a compression spring therein, and clutch mechanism comprising shoes symmetrically seated around said end, inner and outer follower wedges, independent thrust members extending between said wedges for transmitting thrust therefrom to said shoes respectively, each of said thrust members having diagonal flat face engagement with both of said wedges and diagonal cylindrical face engagement with the associated shoe, one of said wedges having thrust engagement with each of said shoes on a plurality of spaced areas.

32. In a draft gear, a barrel having a friction end, a compression spring in said barrel, and clutch mechanism comprising shoes symmetrically seated around said end, inner and outer follower wedges, independent thrust members extending between said wedges for transmitting thrust therefrom to said shoes respectively, each of said shoes having thrust engagement with one of said Wedges on a plurality of spaced areas, each of said thrust members having diagonal face engagement with both of said wedges and diagonal cylindrical face engagement with the associated shoe.

33. In a draft gear, a barrel having a friction end, a compression spring therein, and clutch mechanism comprising shoes symmetrically seated around said end, inner and outer follower wedges, independent thrust members extending between said wedges for transmitting thrust therefrom to said shoes respectively, each of said thrust members having diagonal face engagement with both of said wedges and with the associated shoe, at least one of said diagonal faces having a cylindrical form, each of said shoes also having thrust engagement with one of said wedges on a plurality of spaced areas.

34. In a friction gear, a housing having a flaring open end, a compression spring, friction means, and a securing bolt, said friction means comprising inner and outer follower wedges, a plurality of friction shoes symmetrically seated against said flaring open end, thrust means associated with each shoe and having diagonal cylindrical face engagement therewith and with one of said follower wedges and having fiat face engagement with the other of said wedges, one of said follower wedges having thrust engagement with said shoes.

35. In a friction gear, a housing having a flaring open end, a compression spring, friction means, and a securing bolt, said friction means comprising inner and outer follower wedges, a plurality of friction shoes symmetrically seated against said flaring open end, thrust means associated with each shoe and having diagonal face engagement therewith and with each of said follower wedges, said inner follower wedge having thrust engagement with each of said shoes on a plurality of spaced areas.

36. In a friction absorbing device, a housing having an open end, a compression spring, a

' clutch mechanism seated in said open end, and a spaced areas.

retaining bolt, said mechanism comprising inner and outer wedges, a plurality of symmetrically arranged friction shoes, and thrust means associated with each shoe, said thrust means having diagonal cylindrical face engagement with the associated shoe and diagonal flat face engagement with each of said wedges, one of said wedges having thrust engagement with each of said shoes on 37. In a friction absorbing device, a housing having an open end, a compression spring, a clutch mechanism seated in said open end, and a retaining bolt, said mechanism comprising inner and outer wedges, a plurality of symmetrically arranged friction shoes, and thrust means associated with each shoe, said thrust means having diagonal cylindrical face engagement with the associated shoe and diagonal flat face engagement with each of said wedges, one of said wedges having thrust engagement with each of said shoes along a plurality of spaced areas lying in a single plane.

38. In a friction absorbing device, a housing having an open end, a compression spring, a clutch mechanism seated in said open end, and a retaining bolt, said mechanism comprising inner and outer wedges, a plurality of symmetrically arranged friction shoes and thrust means associated with each shoe, said thrust means having diagonal cylindrical face engagement with the associated shoe and diagonal face engagement with each of said wedges, and means on one of said wedges interlocking with each of said shoes to prevent relative rotation thereof.

39. In a friction absorbing device, a housing having an open end, a compression spring, a clutch mechanism seated in said open end, and a retaining bolt, said mechanism comprising inner and outer wedges, a plurality of symmetrically arranged friction shoes and thrust means associated with each shoe, said thrust means having diagonal cylindrical face engagement with the associated shoe and diagonal face engagement with each of said wedges, and means on said inner wedge interlocking with each of said shoes to preventrelative rotation thereof.

40. In a friction absorbing device, a housing having an open end, a compression spring, a clutch mechanism seated in said open end, and a retaining bolt, said mechanism comprising inner and outer wedges, a plurality of symmetrically arranged friction shoes,and thrust means associated with each shoe, said thrust means having diagonal cylindrical face engagement with the associated shoe and diagonal face engagement with each of said wedges, and means on said inner wedge interlocking with each of said shoes to prevent relative rotation thereof, said inner Wedge having thrust engagement with each shoe on a plurality of spaced areas on opposite sides of said interlocking means.

RAYMOND C. PIERCE. EDMUND 1?. KINNE.

Images