US1247558A - Gearing. - Google Patents

Description

W. L. McDONALD & P. P. STEWART.

GEARING.

APPLICATION FILED MAR. 25. HIM.

Patented Nov, 20, 1917.

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ILL 77 $022 jmLZ l- 157 640073? W. L. MCDONALD & P. P. STEWART.

GEARING. APPLICATION FILED MAR. 25. I914- Patented N 0v. 20, 191?,

4 SHEETS-SHEET 3.

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W. L. McDONALD & P. P. STEWART.

GEARING. APPLICATION FILED mmzs. 1914.

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WILLIAM L. MCDONALD AND PAUL P. STEWART, OF CHICAGO, ILLINOIS.

' GEARING.

Specification of Letters Patent.

Patented Nov. 20 191?.

Application filed March 25, 1914. Serial No. 827,017.

To all whom it may concern: Be it known that we, WILLIAM L. McDon- ALD and PAUL P. STEWART, citizens of the United States, and residents of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Gearing; and we do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to improvements in differential gearing, more especially intended for application to motor driven vehicles, and consists of the matters hereinafter described and more particularly pointed out in the appended claims. In the more familiar type of differential gearing heretofore in use, if one of the two traction wheels driven by' the differential gearing speeds ahead of the other on account of losing its grip .and slips or slides as a result, the tendency is for all or substantially all of the driving force of the driving shaft to be imparted to that wheel. Said force is thus lost or dissipated in the increased speed of the said wheel which races without effect, while the other wheel,

which has a traction grip, receives practically no driving force and stands still. With such differential gearing, the vehicle will not be driven forward unless both wheels have a traction grip.

The object of this invention is to provide a differential gearing in which either of the traction wheels driven by the gearing will be automatically disconnected from driving connection with the gearing the instant that it starts to rotate more rapidly than the associated traction wheel, as in turning a corner, said wheel remaining thus as long as its higher speed of rotation continues, but in which said wheel will be automatically returned to its operative driving connection with the gearing when its speed falls to that of its companion wheel. And if for any reason one wheel loses, or tends to lose its traction grip, it will only receive driving force in proportion to tl e resistance offered by it, while the balance of the force of the differential gearing will be imparted to the other Wheel, that is to say, to the one retaining its traction grip. The racin'g.that may occur in the case of the ordinary differential gearing is therefore obviated in the improved gearing.

In the draw1ngs:

Figure 1 is a view representing a section through the improved differential gearing in the plane of the longitudinal central axis of the two part shaft of the traction wheels.

Fig. 2 is a side elevation of the same.

Fig. 3 is a view representing a section through Fig. 1, in a plane indicated by the line 3-3 thereof.

Fig. 4 is a View representing a section through Fig. 1, in a plane indicated by the line 4-4 thereof.

Fig. 5 is a view representing a side elevation of the driven gear connected with the casing of the gearing.

Figs. 6 and 7 are views representing elevations of opposite sides of the clutch members used in the gearing.

Figs. 8 and 9 are diagrammatic views, partly in plan and partly in section, illustrating the different positions of the clutch members in the operation of the gearing.

Fig. 10 is a sectional view similar to that shown in Fig. 1 representing a modified form of the invention.

Fig. 11 is a view representing a transverse section through Fig. 10 in a plane indicated by the line 11-l1of Fig. 10.

Fig. 12 is a View representing a section through Fig. 10 in a plane indicated by the line 1212 of Fig. 10.

Referring now to that embodiment of the invention illustrated in the drawings and particularly in Figs. 1-9, inclusive, 10 indicates the main drive shaft, and 11, 11, the two shafts or parts, comprising a two part driven shaft, each of which is connected to one of the traction wheels of the automobile or other type of vehicle to which the gearing is applied. Each shaft or shaft part is attached to a fiat ring or head 12, having bearing in a rotative casing indicated as a whole by the numeral 13, which is driven from the main drive shaft 10, and which incloses the clutch members and the devices for actuating them by means of wh ch said casing is operatively connected with the shaft heads.

The casing 13 consists of two cylindrical shells 14, 14, which inclose an annular chamber about the proximate ends of the shaft parts 11, 11. Each shell 14 has a flat end wall l4 which engages the outer face of a shaft head 12 and acts to retain the same in the casing. Said shell has an annular flange 14 forming a hub bearin for a sleeve 12 fixed to the shaft head. he head 12, as shown, is attached to its associated shaft part by means of a key 12.

18 indicates an annular plate interposed between the two shells 14 and rigidly connected thereto by means of suitable bolts which also preferably provide the means for connecting the shells 14 together. Said plate may project radially beyond the easing 13 and is there provided on one side with beveled gear teeth 19, which mesh with a pinion 10 fixed on the drive shaft 10. This constitutes the driving connection between the drive shaft 10 and the casing 13. The plate 18 also projects radially into the chamber inclosed by the casing and is there provided on both sides with a set of annularly arranged cam teeth 20.

21, 21 indicate clutch members located in the casing, there being one clutch member interposed between each shaft head 12 and the proximate set of cam teeth 20. Each clutch member consists of a fiat ring 22, rotatively mounted on its associated shaft part 11 and having teeth 24 on one side adapted for engagement with similarly formed teeth 23 on the adjacent face of the shaft head 12 and having cam teeth 26 on its opposite face adapted for engagement with the cam teeth 20 on the annular plate 18.

Each clutch member 21 is provided on its inner side with an annular flange 27, which has rotative bearing on the adjacent ends of the shaft parts 11. The two flanges are provided with longitudinally extending lugs 28 and intermediate notches 29, the lugs of one clutch member engaging in the notches of the other clutch member. The lugs are made of less arcuate length than the notches in which the engage, so that a limited rotative play is permitted between the two clutch members, as clearly shown in Fig. 3. A coiled spring 30 is interposed between the two clutch members, said spring acting to force said clutch members apart and bring and hold the teeth 24 of each clutch member into engagement with the teeth 23 on its associated shaft head, the cam teeth 26 being released from engagement with the cam teeth 20 on the annular plate 18, whenever the heads 12 and with them the locking rings 22 tend to travel more rapidly than the casing, as clearly shown in Fig. 8.

' The operation of the improved gearin s as follows. The rotation of the shaft 10 imparts rotative movement to the casing 13' through the beveled gear 10 and the gear teeth 19 which are fixed to the casing. Before movement is imparted to the casing, the clutch members are in the position indicated in Fig. 8, namely, that position last above described. The rotative movement imparted to the casing will cause the cam teeth 20, which are rigid with the casing, to move in One direction or the other, say for example, the direction indicated by the arrow 00. This causes the cam teeth 20 to forcibly engage the cam teeth 26, as illustrated on the lower side of Fig. 9, both clutch members being normally engaged in this way when both traction wheels offer resistance. The action of the cam teeth fixed to the casing forces the teeth 24 on each clutch member to operatively engage teeth 23 on their associated shaft heads so as to positively rotate the two shaft parts as long as there is any tendency of shaft parts to lag behind the casing, that is to say, as long as they offer resistance to rotation.

Should one traction wheel tend to speed ahead of the other, it will act, by reason of the engagement of the teeth 24 on its associated shaft head, with the teeth 23 on the associated clutch member, to carry said clutch member forward ahead of the casing, this movement between the two clutch members being made possible by reason of the play permitted between the two clutch members heretofore referred to. This brings the parts into the relative position indicated in the upper side of Fig. 8 where the cam teeth 26 on the clutch member are disengaged from the cam teeth 20 moving with the casing, so that the clutch member is free to mov longitudinally on the shaft away from the shaft head. This position is continued until the free rotative movement of the lugs 28 and notches 29 is taken up, after which the clutch member moves longitudinally, allowing the shaft head to move ahead of the clutch member as shown in the upper part of Fig. 9, and this movement of the parts will continue as long as the shaft and its associated wheel tend to rotate faster than the casing. As soon as this wheel and shaft slow down relatively to the casing, the parts will be again lockingly engaged with the casing, whereupon both wheels will be driven in the rotation of the casing and with the same rotative speed.

In Figs. 10-12, inclusive, there is shown a slightly modified form of the invention, in which the coiled spring 30 is dispensed with and a friction band is interposed between the clutch members 21, 21 and their respective associated heads 12 in such manner as to normally tend to make the said clutch members rotate with their respective heads.

In the figures referred to,severa1'of the parts are indicated by the same numerals of reference heretofore used in connection with the like parts of other figures. 12*, 12 indimamas cate the heads in this case and 21, 21 the clutch members associated with said heads. Each of the heads 12 is provided on its face, adjacent its associated clutch member 21*, with an annular recess 12 in which is located a flat, split friction band 30 Said friction band 30 is provided with fixed pins 30 (there being, as shown in the drawings, two of such) which project through holes or openings 30 in the associated clutch member 21 Said pins are slightly smaller than the holes 30 through which they extend, so that a slight play is permitted between the friction band 30 and its associated clutch member 21, allowing free longitudinal movement of the clutch member 21.

The friction band performs substantially the same function as the coiled spring 30, heretofore referred to, and tends to carry the associated clutch member 21 with the associated head 12 until the limited rotative play between the lugs 28 and notches 29 has been absorbed. Any further rotative movement of the associated heads will cause the teeth 23 and 24 to become disengaged, as before. I

The drawings show the differential as being shaft driven and designed with reference to the non-floating type of axle, but is equally applicable to any form of powerdriven differential.

While in describing the invention, we have referred to certain details of mechanical construction and arrangement, it is to be understood that the invention is in no way to be limited thereby, except as pointed out in the appended claims.

We claim as our invention:

1. A difierential gearing comprising a power driven casing, a two part driven shaft having rotative bearing in said casing, each shaft part being provided with a shaft head, said casing being provided with a cam member having cam teeth, clutch rings mounted in said casing, there being one clutch ring interposed between each shaft head and said cam member, said clutch ring being provided with cam teeth for engagement with the teeth of said cam member, and being provided on the other side with teeth for engagement with the teeth on its associated shaft head, means acting to yieldingly hold said clutch rings in operative engagement with their respective shaft heads, and means providing for longitudinal play of said clutch ring away from their shaft heads and for limited, relative, rotative movement be tween said clutch rings.

2MA differential gearing comprising a power driven casing, a two part driven shaft having rotative bearing in said casing, a clutch device for each shaft part comprising a clutch member movable longitudinally in said casing, said clutch member and shaft parts being provided with engaging teeth, said casing having a cam member located intermediate said clutch members, said cam member having a set of cam teeth for each clutch member, said clutch member being provided with cam teeth for engagement with the cam teeth of said casing, means acting to normally hold the teeth of each clutch member in engagement with the associated teeth of its shaft part, and means connecting said clutch members permitting limited relative, rotative movement between them.

3. A differential gearing comprising a power driven casing, a two part driven shaft, said shaft arts having bearing in said casing, a clutch device for each shaft part comprisin a clutch member movable longitudinally 1n said casing, said clutch member and shaft parts being provided with engaging teeth and said casing having a member provided with cam teeth, a set for each clutch member, said clutch member being provided with cam teeth for engagement with the cam teeth of said casing, means acting to normally hold the teeth of each clutch member in engagement with the as sociated teeth-of its shaft part, and means connecting said clutch members permitting limited, relative, rotative movement between them.

4. A differential gearing comprising a power driven casing, a two part driven shaft provided with heads having rotative bearing in said casing, and a cam member fixed to said casing intermediate said shaft heads, clutch rings, one for each shaft head, located on either side of said cam member, said cam member being provided with sets of cam teeth, one for each clutch ring, said clutch rings being capable of limited rotative movement relative to each other in said casing and each clutch ring being capa' ble of longitudinal movement between its associated shaft head and the cam member, and yielding means acting to normally hold said clutch rings in engagement with their associated shaft heads, but permitting said clutch rings to be disengaged when the shaft head associated with either ring rotates ahead of the casing.

5. In differential mechanism, in combination, a driving part having major clutch teeth on both sides, shiftable clutch members having major clutch teeth on one side in mesh with teeth of the driving part, each shiftable clutch member having minor clutch teeth on one side thereof, means carried by the respective shiftable clutch members to permit and to limit relative rotative movement of the shiftable clutch members and to allow said members to move toward and from the dr ving part, driven parts each formed with minor clutch teeth on one side for operative engagement with the minor clutch teeth of the respective shiftable clutch members, and yieldable means to urge the shiftable clutch members into mesh with the respective driven parts.

6. In differential mechanism, in combination, a driving part having major clutch teeth on both sides thereof, shiftable clutch members having major clutch teeth on one side in mesh with teeth of the driving part,

- each shiftable clutch member having minor clutch teeth on one side thereof, means carried by the respective shiftable clutch members to permit and to limit relative rotative movement of the shiftable clutch members and to allow said clutch members to move toward and from the driving part, means to maintain the shiftable clutch members in alinement, driven parts each formed with minor clutch teeth on one side for operative engagement with the minor clutch teeth of the respective shiftable clutch members and yieldable means to urge the shiftable clutch members into mesh with the respective driven parts.

7 In differential mechanism, in combination, a driving part having clutch teeth on both sides, shiftable clutch members having teeth on both sides thereof, the teeth on one side of each shiftable clutch member being in mesh with teeth of the driving part, means carried by the respective shiftable clutch members to permit and to' limit relative rotative movement of the shiftable clutch members and to allow said members to move toward and from the driving part, independent shafts, a driven part fixed to one end of each shaft and formed with clutch teeth on one side for operative engagement with teeth of the respective shiftable clutch members, and yieldable means to urge the shiftable clutch members into mesh with the respective driven parts,

8. In differential mechanism, in combination, a rotatable housing, a driving part having clutch teeth on both sides thereof, shiftable clutch members positioned on both sides of the driving part and having clutch teeth on both sides thereof, the teeth on one side of each shiftable clutch member being in mesh with teeth of the driving part, means carried by the respective shiftable clutch members to permit and to limit relative rotative movement of the shiftable clutch members and to allow said members to move toward and from the driving part, independent shafts, a drivenpart fixed to one end of each shaft and formed with clutch teeth on one side for operative engagement with teeth of the respective shiftable clutch members, and yieldable means to urge the shiftable clutch members into mesh with the respective driven parts.

9. A device of the class described, comprising a pair of coaxially disposed driven members, having an annular space between them, a single driving ring dlSPOSBd concentrio with the members and extending into the annular space, devices interposed between the ring and each of the members for operatively connecting the ring and members, means for limiting angular movement of the device associated with one member relative to the device associated with the other member for the purpose set forth, and a shaft secured to each of said members.

10. A device of the class described, comprising a pair of co-axially disposed driven collars having an annular space between them, a single driving ring disposed concentric with the collars and extending into the annular space, devices interposed between the ring and each of the collars for operatively connecting the ring and collars, means for limiting angular movementv of the device associated With one collar relative to the device associated with the other collar for the purpose set forth, and a shaft secured to each of said collars.

11. A device of the class described, comprising a pair of co-axially disposed driven members having an annular space between them, a single driving ring disposed concentric with the members and extending into th annular space, devices carried with the ring interposed between the ring and each of the members for operatively connecting the ring and members, means for limiting angular movement of the device associated with one member relative to the device associated with the other member for the purpose set forth, and a shaft secured to each of said members.

12. A device of the class described, comprising a pair of co-axially disposed driven members having an annular space between them, a single driving ring disposed concentric with the members and extending into the annular space, sleeves interposed between the ring and each of the members for operatively connecting the ring and members, means for limiting angular movement of the sleeve associated with one member relative to the sleeve associated with the other member for the purpose set forth, and a shaft secured to each of said members,

13. A device of the class described, comprising a pair of co-axially disposed driven members having an annular space between them, a single driving ring disposed concentric with the members and extending into the annular space, sleeves interposed between the ring and each of the members for operatively connecting the ring and members, means carried by the sleeves for limiting angular movement of the sleeve asso ciated with one member relative to the sleeve associated with the other member for the purpose set forth, and a shaft secured to each of said members.

14. A device of the class described, comprising a pair of co-axially disposed driven sleeve associated with the other member for the purpose set forth, and a shaft secured 15 to each of said members.

In testimony, that we claim the foregoing as our invention we affix our signatures in the presence of two witnesses, this 20th day of March A. D. 1914:.

WILLIAM L. MoDONALD. PAUL P. STEWART.

Witnesses:

GEO. R. WILKINs, T. H. ALrREns.

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