US3578118A

US3578118A - Cam operated positive clutch and brake

Info

Publication number: US3578118A
Application number: US862656A
Authority: US
Inventors: Lewis K Wetzel
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1969-10-01
Filing date: 1969-10-01
Publication date: 1971-05-11
Anticipated expiration: 1988-05-11
Also published as: JPS4838654B1; DE2047985B2; GB1319133A; DE2047985C3; FR2064888A5; DE2047985A1

Abstract

A clutch and brake mechanism includes a constantly rotating drive gear mounted for rotation about the driven shaft. A clutch hub is keyed to the shaft for rotation therewith and axial movement thereon, and has a lug which is to be engaged with either the drive gear or a stationary stop. A guide vane is mounted on the hub for axial movement therewith and rotation thereon, and is keyed to the drive gear for rotation therewith and axial movement thereon. The vane has a lug with a constantly rotating knife or cam blade. A nonrotatable control knife or cam blade is translated between the vane and the gear or the vane and the stationary stop to cam the vane directly and thereby shift the hub lug into engagement with either the gear or the stop.

Description

United States Patent [72] Inventor Lewis K. Wetzel South Burlington, Vt. [21 Appl. No. 862,656 [22] Filed Oct. 1, 1969 [45] Patented May 11, 1971 [73] Assignee General Electric Company [54] CAM OPERATED POSITIVE CLUTCH AND BRAKE 9 Claims, 6 Drawing Figs.

[52] 0.5. CI 192/16, 192/18R, 192/24, 192/67R [51] Int. Cl F1611 67/02 [50] FieldofSearch 192/18,18 (B), 16, 24,102

[56] References Cited UNITED STATES PATENTS 2,787,355 4/1957 Dodge 192/18X 3,061,059 10/1962 Kindlien etal 3,410,381 11/1968 Henshawetal ABSTRACT: A clutch and brake mechanism includes a constantly rotating drive gear mounted for rotation about the driven shaft. A clutch hub is keyed to the shaft for rotation therewith and axial movement thereon, and has a lug which is to be engaged with either the drive gear or a stationary stop. A guide vane is mounted on the hub for axial movement therewith and rotation thereon, and is keyed to the drive gear for rotation therewith and axial movement thereon. The vane has a lug with a constantly rotating knife or cam blade. A nonrotatable control knife or cam blade is translated between the vane and the gear or the vane and the stationary stop to cam the vane directly and thereby shift the hub lug into engagement with either the gear or the stop.

' PATENTED um um:

sum 1 n5 3 INVENTORI LEWIS K.WETZEL, BY%LZ W HIS ATTORNEY.

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INVENTOR: LEWIS K.WETZEL,'

HIS ATTORNEY.

PATENIEU m1 1 |97| SHEET 3 0F 3 INVENTOR'. LEWIS K.WETZEL, ,QZ

HIS ATTORNEY.

CAM OPERATED IOSITIVE CLUTCH AND BRAKE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to clutch mechanisms and particularly to such mechanisms wherein a driven member must be disengaged in a positive prescribed orientation and then reengaged in a positive prescribed orientation with respect to a driving member.

2. Description of the Prior Art In a high rate of fire Gatling-type weapon wherein a cluster of barrels rotates about the longitudinal axis of the weapon and is fed with rounds of ammunition by a sprocket system rotating about a parallel axis, it is necessary to disengage and engage the sprocket system to the barrel cluster in positive prescribed orientations. It is desirable at the end of a firing burst to immediately stop handing off rounds from the sprocket system to the barrel cluster; and at the start of a firing burst to immediately and synchronously hand off rounds from the sprocket system to the barrel cluster. A clutch which provides this function is shown in US. Pat. No. 3,410,381 issued on Nov. 12, 1968 to Robert H. Henshaw et al. The l'lenshaw et al. clutch utilizes a longitudinal stationary control knife blade which is used to guide a shiftable clutch member to altematively engage either a driving member or a stationary member. The input signal is applied to the shiftable clutch member and must be of relatively substantial magnitude to effect this shifting of the shiftable clutch member.

Accordingly, it is an object of this invention to provide an improved l-Ienshaw et all type mechanism requiring an input signal of a relatively small magnitude and also incorporating positive control 'during the reengagement cycle as well as during disengagement.

BRIEF SUMMARY OF THE INVENTION A feature of the invention is a clutch mechanism wherein the power required for shifting the shiftable clutch member is obtained from the constantly rotating member which is driven by the external power source. The mechanism further includes a driven shaft which is to be connected to the constantly rotating member in a timed position when the clutch is engaged, and which is to be stopped and locked in a particular stationary position when the clutch is disengaged while the constantly rotating member continues to rotate. The connecting device is a sliding hub which is keyedto the driven shaft and rotates with it but which can be shifted longitudinally along the shaft. This hub has a set of radial lugs, one for each of the acceptable timed positions which alternatively engage either similar lugs on the constantly rotating member when the clutch is engaged, or stationary lugs on the stationary housing when the clutch is disengaged-The hub is shifted longitudinally along the driven shaft by interaction between a set of rotating knife blades and a nonrotating, but, upon command, longitudinally shiftable, control knife blade. The rotating knife blades extend radially from an additional hub which is attached through a bearing to the sliding hub so that it can rotate freely with respect to the sliding hub, but must move longitudinally therewith. This additional hub is keyed to the constantly rotating member so that it rotates with the member but can shift longitudinally with respect to said member.

BRIEF DESCRIPTION OF THE DRAWING These and other objects, features and advantages of this invention will be apparent from the following specification thereof taken in conjunction with the accompanying drawing in which:

FIG. 1 is an exploded perspective view of a clutch mechanism embodying this invention;

FIG. 2 is a longitudinal cross section through the clutch mechanism of FIG. I when engaged;

FIG. 3 is a longitudinal cross section through the clutch mechanism of FIG. 1 when disengaged;

FIG. 4 is a top view of the clutch mechanism of FIG. 2;

FIG. 5 is a top view of the clutch mechanism of FIG. 3; and

FIG. 6 is a schematic diagram showing the knife blade interengagements.

THE PREFERRED EMBODIMENT The clutch mechanism includes a housing 10, a constantly rotating member 12 here shown as a drive gear (turning in the direction A), and a driven shaft 14 suitably journaled as at 14a, 14b. In a Gatling-type weapon, the drive gear might receive its power from the rotating barrel cluster, and the driven shaft might drive the ammunition feed sprocket assembly. The driven shaft I4 includes a portion having a circular cross section and a portion 18 having two diametrically opposed flat surfaces 20. Two longitudinally spaced-apart sets 22, 24, or pairs of diametrically opposed detent cups are formed into the shaft portion 18.

The .drive gear 12 includes a hub portion 26, a web portion 28, a gear ring portion 30, and an intermediate hub portion 32 projecting longitudinally from the web portion. A plurality of sets of notches 34 are provided, one for each desired locking position. Each set includes a deep, leading notch portion 36, having a leading face 38 and a trailing face 40, and a shallow, trailing notch portion 42 having a leading ramp face 44 and a trailing face 46. The hub 26 is journaled to the shaft portion 16 by a two-piece bearing 48.

A clutch hub assembly 50 is disposed on the driven shaft portion 18; and includes a sliding hub 52 and a vane 54.-The sliding hub 52 has a hub body 56 having a central bore 58 with a cross section mating with and thereby keyed to the shaft portion 18. Four locking arms or lugs 60 extend radially from the hub body, each having a respective trailing face 62. The vane 54 includes a hub portion 64 from which four arms or lugs 66 extend radially, each having a knife edge 68 formed into its leading face. The hub portion 64 is journaled to the sliding hub portion 56 by a two-piece bearing 68 and is captured thereto by a disc 70 mounted to the hub by four machine screws 72. Two diametrically opposed radial bores are provided on the hub body 56 and are threaded respectively to receive two spring-loaded ball detent assemblies 74. The ball detent assemblies are adapted to alternatively engage either cup set 22 or 24. Thus the hub assembly 50 is held in either the fully engaged or fully disengaged positions with respect to the shaft I4. The hub 52 is free for longitudinal movement with respect to the shaft 16, subject to being detented at either

cups

22 or 24, but is constrained against rotation with respect to the shaft.

The housing 10 has a rotary solenoid mounted to its exterior. The armature 82 extends through the housing and has one end of an arm 84 fixed thereto. The distal end of the arm has a slot 86. A slide bar 88 is keyed for reciprocation'to the interior of the housing. One end of the slide bar a pin 90 which is engaged by the slot 86. The distal end of the slide bar has a knife blade wedge portion 92 extending therefrom and adapted to interfere with the knife blade ends 68 of the vane arms 66. A spring 94 is coupled between the arm 84 and the housing 10 to bias the wedge portion 92 towards the ring gear 30. The housing also includes a projecting block 96 having a shoulder cutout 98 which is adapted to abut and halt the leading faces 62 of the lugs 60 when the hub 52 is shifted away from the ring gear 30 as shown in FIGS. 3 and 5, and to clear the lugs when the hub is shifted toward the ring gear, as shown in FIGS. 2 and 4.

A complete cycle of engagement and disengagement may be described as follows:

I. Assume a present state of disengagement. The drive gear 12 is rotating continuously, and the vane 54, whose arms 66 are respectively captured in the slots 36 of the drive gear 12 is also rotating continuously. The clutch hub 52 is remote from the drive gear 12 and one lug 60 is locked against rotating by the stop shoulder 98.

2. The solenoid is energized to move the control knife blade wedge;92 away from the drive gear 12. As the wedge moves laterally, three interactions are possible:

a. lf the leading edge of the knife blade 68 of the next adjacent arm 66 of the continuously rotating vane 54 has passed'the leading edge of the control wedge 92 before the control wedge has reached the plane of the leading edge of the vane, as shown in FIG. 6A, the rotating vane knife blade will cam the control wedge back against the force of the solenoid as shown in FIG. 68, until the knife blade has passed the control wedge. Then the solenoid will be able to continue to move the control wedge away from the drive gear as shown in FIG. 6C to its engagement affecting position, abutting the shoulder 102, before the arrival of the next vane arm, as shown in FIG. 6D.

if the next adjacent rotating vane knife blade has passed the control wedge completely, the solenoid will be able to move the control wedge away from the drive gear to its engagement affecting position before the arrival of the next vane arm.

c. If the next adjacent rotating vane knife blade and the control wedge meet edge-on they must pass to one side or the other, to interact either as (a) or (b) above.

3. When the control wedge has completed its travel away from the drive gear and is in its engagement affecting position, a side of the wedge serves as a camming surface for the next adjacent rotating vane knife blade to longitudinally shift the vane towards the drive gear. Since the hub 52 and the vane 54 are keyed against relative longitudinal movement, the hub 52 also must shift longitudinally towards the drive gun, so that its locked lug 60 shifts away from the stop shoulder 98. When the locked lug has been shifted completely away from the stop shoulder 98 by the camming interaction between the control wedge and the vane knife blade, the lugs are respectively fully aligned with the bearing faces 46 which engage and rotate the lugs and the integral therewith hub and the keyed thereto shaftThe spring-loaded detents S8 engage the cups 24 to prevent longitudinal oscillation of the hub.

4. To disengage the clutch, the control signal is removed from the solenoid and the return spring 94 starts to move the control knife blade wedge 92 towards the drive gear 12. As the wedge moves laterally the three interactions described above at 2(a), (b) and (c) are possible.

5. When the control wedge has completed its travel towards the drive gear and is in its disengagement affecting position, abutting the shoulder 102, the other side of the wedge serves as a camming surface for the next adjacent rotating vane knife blade to longitudinally shift the vane away from the drive gear. Since the hub 52 and the vane 54 are keyed against relative longitudinal movement, the hub 52 also must shift longitudinally away from the drive gear, so that each of its engaged lugs 60 shift away from its respective bearing face 46. When the lugs have been shifted completely away from the bearing faces, thereby decoupling the hub 52 from the drive gear 12, one lug 60 abuts the stop shoulder 98 and halts rotation of the hub 52. The spring-loaded detents 74 engage the cups 22 to prevent longitudinal oscillation of the hub. The drive gear 12 and the vane 54 continue their rotation, the driven shaft 14 is stationary.

In the event that relatively high rotational inertias are to be started and stopped it may be desirable to incorporate springloaded buffers (not shown) in the lugs on the sliding hubs or the stop shoulder 98 to cushion the affect of the high accelerations involved.

To prevent inadvertent engagement from handling or vibration, a blocking surface 106 is effectively provided on the rotating driven gear which prevents longitudinal shifting of the hub from the disengaged position at all rotational positions of the drive gear except in the area of normal engagement, during which times the longitudinal position of the hub is controlled by the interaction of the control wedge and the knife blades. A similar blocking surface 108 is effectively provided on the housing to prevent disengagement of the clutch except where controlled by interaction between the knife blades.

If desired to preclude backlash on disengagement, a springloaded dog, not shown, may be provided on the housing adjacent to the stop surface 98, which is cammed away as the dog approaches the surface and which then snaps in behind the dog to lock it against the surface.

lclaim:

l. A clutch mechanism comprising:

an elongated shaft journaled for rotation;

a clutch member mounted on said shaft for rotation therewith and for reciprocal longitudinal movement therealong;

an externally powered drive member supported for rotation about said shaft;

stationary means;

first lug means disposed on said drive member;

second lug means disposed on said stationary means;

third lug means disposed on said clutch member and adapted at a first longitudinal station of said clutch member on said shaft to engage said first lug means whereby said drive member drives said shaft and at a second longitudinal station of said clutch member on said shaft to engage said second lug means whereby said stationary means halts said shaft; and

actuation means including:

vane means coupled to said clutch member for longitudinal movement therewith along said shaft but free for rotation relative to said clutch member, and coupled to said drive member for rotational movement therewith but free for longitudinal movement relative thereto, said vane means having a lug extending therefrom with a knife edge distal portion,

a knife edge member mounted to said stationary means and moveable to and between a first and a second station,

said knife edge member when disposed at said first station being disposed in the path of said vane lug knife edge distal portion when said third lug means is engaged with said first lug means and adapted to engage and cam said vane lug knife edge distal portion longitudinally towards said second lug means whereby said third lug means disengages said first lug means and engages said second lug means, and

said knife edge member when disposed at said second station being disposed in the path of said vane lug knife edge distal portion when said third lug means is engaged with said second lug means and adapted to engage and cam said vane lug knife edge distal portion longitudinally towards and first lug means whereby said third lug means disengages said second lug means and engages said first lug means.

2. A clutch mechanism according to claim 1 wherein:

said drive member is provided with a plurality of equally angularly spaced apart first lug means;

said clutch member is provided with like plurality of equally angularly spaced apart third lug means; and

said vane means is provided with a like plurality of equally angularly spaced apart lugs with respective knife edged distal portions.

3. A clutch mechanism according to claim 1 wherein said drive member comprises a gear and said first lug extends longitudinally therefrom.

4. A clutch mechanism according to claim 2 wherein:

said drive member comprises a gear housing an annular hub extending longitudinally therefrom and spaced from said shaft,

each of said first lug means being provided by a longitudinal notch. in said hub.

5. A clutch mechanism according to claim 4 wherein each of said longitudinal notches in said hub includes a first portion adapted to receive a respective lug of said vane means and a second portion adapted to receive a respective third lug means of said clutch member.

6. A clutch mechanism according to claim 5 wherein each of said longitudinal notches has a ramp surface leading thereinto.

7. A clutch mechanism according to claim 1 further including control means resiliently coupled to said knife edge 6 edge member beyond said first and second stations' 9. A clutch mechanism according to claim 1 further includin g means effective to preclude longitudinal movementof said 1 vane means during certain angular distances of rotation and ineffective during the remaining angular distances of rotation.

Claims

1. A clutch mechanism comprising: an elongated shaft journaled for rotation; a clutch member mounted on said shaft for rotation therewith and for reciprocal longitudinal movement therealong; an externally powered drive member supported for rotation about said shaft; stationary means; first lug means disposed on said drive member; second lug means disposed on said stationary means; third lug means disposed on said clutch member and adapted at a first longitudinal station of said clutch member on said shaft to engage said first lug means whereby said drive member drives said shaft and at a second longitudinal station of said clutch member on said shaft to engage said second lug means whereby said stationary means halts said shaft; and actuation means including: vane means coupled to said clutch member for longitudinal movement therewith along said shaft but free for rotation relative to said clutch member, and coupled to said drive member for rotational movement therewith but free for longitudinal movement relative thereto, said vane means having a lug extending therefrom with a knife edge distal portion, a knife edge member mounted to said stationary means and moveable to and between a first and a second station, said knife edge member when disposed at said first station being disposed in the path of said vane lug knife edge distal portion when said third lug means is engaged with said first lug means and adapted to engage and cam said vane lug knife edge distal portion longitudinally towards said second lug means whereby said third lug means disengages said first lug means and engages said second lug means, and said knife edge member when disposed at said second station being disposed in the path of said vane lug knife edge distal portion when said third lug means is engaged with said second lug means and adapted to engage and cam said vane lug knife edge distal portion longitudinally towards and first lug means whereby said third lug means disengages said second lug means and engages said first lug means.

2. A clutch mechanism according to claim 1 wherein: said drive member is provided with a plurality of equally angularly spacEd apart first lug means; said clutch member is provided with like plurality of equally angularly spaced apart third lug means; and said vane means is provided with a like plurality of equally angularly spaced apart lugs with respective knife edged distal portions.

4. A clutch mechanism according to claim 2 wherein: said drive member comprises a gear housing an annular hub extending longitudinally therefrom and spaced from said shaft, each of said first lug means being provided by a longitudinal notch in said hub.

7. A clutch mechanism according to claim 1 further including control means resiliently coupled to said knife edge member for moving said member between said first and second stations.

8. A clutch mechanism according to claim 1 further including means for precluding longitudinal movement of said knife edge member beyond said first and second stations.

9. A clutch mechanism according to claim 1 further including means effective to preclude longitudinal movement of said vane means during certain angular distances of rotation and ineffective during the remaining angular distances of rotation.