US3663770A

US3663770A - Electrical rotary joint

Info

Publication number: US3663770A
Application number: US93938A
Authority: US
Inventors: Ernest Groskopfs
Original assignee: Spar Aerospace Products Ltd
Current assignee: Spar Aerospace Products Ltd
Priority date: 1970-12-01
Filing date: 1970-12-01
Publication date: 1972-05-16
Anticipated expiration: 1989-05-16
Also published as: CA929620A

Abstract

A rotary electrical joint consisting of at least one, and preferably two, rotary electrical contacts adapted to be secured to a rotating member, and at least one, preferably two, oscillating electrical contacts mounted for movement to and fro in an arc about the axis of rotation of the rotary contacts. The oscillating contacts are held in electrical engagement with the rotary contacts during at least a portion of one revolution of the rotary contacts. Circuit breaker means is provided to cyclically disengage the contacts at predetermined intervals during the rotation of the rotary contact and return drive means is provided to drive the oscillating contact in the opposite direction to the rotation of the rotary contact when the contacts are disengaged.

Description

United States Patent Groskopfs [4 1 May 16, 1972 [s41 ELECTRICAL ROTARY JOINT 3,138,672 6/1964 Shlesinger ..200/11 R [72} Inventor: Ernest croskopfs Caledon East Ontario, 3,482,071 12/1969 Mlller ..200/ l6 A Canada 7 Primary Examiner-J. R. Scott [73] Assignee: Spar Aerospace Products Limited, Toronto y h r t nhaugh & C0-

lnternational Airport, Ontario, Canada [57 BSTRACT A [22] Filed: Dec. 1,1970 1 A rotary electrical joint consisting of at least one. and [21] PP 93,938 preferably two, rotary electrical contacts adapted to be secured to a rotating member. and at least one, preferably 52 US. 01 ..200/11 R ZOO/16A 200/18 tw1scillating electrical contacts mounted for movement 260/153 and fro in an are about the axis of rotation of the rotary con- 51 mm .L ..H0lh 19/54 HOlh 27/76 The mating are held in eltctrical engage- [58] Field of'earch "200/1 1 R A 17 18 23 ment with the rotary contacts during at least a portion of one 7 11 R 11 3l0/24'5 revolution of the rotary contacts. Circuit breaker means is provided to cyclically disengage the contacts at predetermined intervals during the rotation of the rotary contact and [56] References cued return drive means is provided to drive the oscillating contact UNITED STATES PATENTS in the opposite direction to the rotation of the rotary contact when the contacts are disengaged. 3,504,141 3/1970 Webster ..200/25 1,995,708 3/ 1935 Fischer ..200/ll R" 20 Claims,7Drawing Figures 43 H 44 I i 36 2O 90 82 8 4 {11 1 I1 Q /s nli 1: i4 72- K 68-1 1. 1 gz-s 1 4- 12-? i 60 1 60" 4 32 54 I 5762 88 I 72% so 86 90 W 1 -4 6 74 I II [I 4 4 Sheets-Sheet l Patented May 16, 1972 INVENTOR. ERNEST GROSKOPFS FIG'G ATTORNEYS Patented May 16, 1972 3,663,770

4 Sheets-Sheet 2 INVENTOR. ERNEST GROSKOPFS ATTORNEYS Patented May 16, 1972 4 Sheets-Sheet 3 I N VENT JP v E RN E ST GROSKOPFS ATTORNEYS Patented May 16, 1972 3,663,770

4 Sheets-Sheet 4 [.N'Vfi. 1 0r" ERNEST GROSKOPF'S Mai/1& f

ATTORNEYS ELECTRICAL ROTARY JOINT FIELD OF INVENTION This invention relates to rotary electrical joints. In particu-. lar, the invention relates to a rotary connected joint for connecting two components surmounted for rotation relative to one another so as to provide electrical contact between the components. I

PRIOR ART In the known rotary electrical joints, the common practice is to provide a slip-ring type of connection between the two rotating members so that electrical power can be transferred from one member to another. It will be understood that the two rotating bodies cannot be connected, by conventional electrical wiring as the wiring would become twisted as the bodies rotate relative to one another. The difiiculty withthe conventional slip-ring type of joint is that it is subject to wear and, in some instances, considerable power is required in order to overcome the frictional resistance to rotation of the slip'rings. In addition, the slippingaction is not a satisfactory method of transferring electrical signals in that it can create radio noise interference.

One of the areas in which a rotary electrical joint is required is in the field of space communications. The slip-ring type of electrical joint is unsatisfactory for use in spacecraft for the reasons mentioned above. The problems associated with wear and power consumption of the slip-ring joint become more acute in use in spacecraft applications. Rotary electrical joints are required in spacecraft in order to connect the space capsule to solar cells which are mounted on solar panels which extend outwardly from the spacecraft. To be effective, the solar panels must be oriented to face the sun and when a spacecraft is in orbit, it is necessary to maintain a substantially continuous rotation of the solar panels relative to the spacecraft.

The wear problems associated with the conventional slipring joints have been eliminated by the joint of the present invention due to the fact that the electrical contacts do not slip continuously relative to one another and, as shown in the preferred embodiment described hereinafter, the electrical contacts are maintained in a spaced relationship during the recycling operation. 7

The joint of the present invention employs at least two sets of contacts, one contact of each set being electrically connected to one another of the relatively rotating bodies and the recycling of each set of contacts is carried out while the other set of contacts are in electrical engagement such that there is no interruption in the flow of electrical power or signals between the rotating components.

The rotary electrical joint of the present invention is also distinguished by a number of novel structural features which contribute to the successful operation of the joint. These structural features include the locking arrangement which locks each pair of contacts to prevent rotation of one contact relative to the other when engagement with one another, and a compression spring which serves to maintain the electrical contacts in engagement with one another while locked.-ln addition the coil spring structure which connects the oscillating contacts to the stationary housing also serves to provide a path for conductors extending between the oscillating contacts and the stationary housing.

SUMMARY The present invention overcomes thedifficulties of the prior art described above and provides a rotary electrical joint which is adapted to maintain continuous electrical contact between two relatively rotating bodies without permitting the electrical wiring of either of the two bodies to become excessively twisted as a result of the rotation of one body relative to the other. According to an embodiment of the present invention, this desirable objective is achieved by providing a rotary electrical joint comprising at least two rotary electrical contact means adapted to be secured to a rotating member for rotation therewith about an axis and at least two oscillating electrical contact means mounted for movement to and fro in a predetermined arc about said axis independently of one another to cooperate with the rotary contacts to provide at least two pairs of complementary contacts, each consisting of a rotary contact and an oscillating contact. Means are also provided for maintaining each pair of contacts in electrical engagement during at least a portion of one revolution of the rotary contacts. Circuit breaker means are provided for cyclically disengaging one pair of contacts while the other pair remains in contact. Return drive means is provided to drive each of the oscillating contact means in a direction opposite to the direction of rotation of the rotary contact means when the oscillating contact is disengaged from the rotary contact by the circuit breaker means.

The invention will be more clearly understood after reference to the following detailed specification read in conjunction with the drawings.

FIG. 1 is a pictorial view of a diagrammatic illustration of a rotary joint without many of the structural elements of an actual joint;

FIG. 2 is a longitudinal sectional view of a rotary electrical joint according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view taken along the line 33 of FIG. 2;

FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. 2;

FIG. 5 is a partially sectional view of a portion of a contact structure of FIG. 2;

FIG. 6 is a small pictorial view of a space vehicle of a type with which the joints of this invention may be used; and

FIG. 7 is a cross-sectional view of a joint of the type having only one set of contacts.

As indicated above, FIG. 1 of the drawings is not intended to illustrate a completely operable structure but rather it serves to illustrate the principle of operation of a rotary electrical joint according toan embodiment of the present invention. The joint is collectively identified by the reference numeral l0.

The reference numeral 12 refers generally to the upper set of complementary contacts and the reference numeral 14 refers generally'to the lower set of complementary contacts. Each set of contacts consists of a rotary contact assembly 16 and an oscillating contact assembly 18. Each of the rotary assemblies 16 are adapted to be secured to a rotary shaft 20. The assemblies 16 are also free to reciprocate longitudinally relative to the shaft 20 in the direction of the arrows A.

The oscillating assemblies 18 are mounted for rotation relative to the shaft 20 by means of suitable ball bearing races 22. As will be seen hereinafter, the oscillating assemblies are also secured to a body which does not rotate with the shaft 20 by a suitable return drive means. In addition, each of the oscillating assemblies 18 is urged into engagement with the rotary assembly 16 by a suitable coil spring, as will be described hereinafter, and the assemblies are locked in engagement when they are in electrical contact.

Each of the assemblies 16 has a cam track surface 24 formed adjacent the peripheral edge thereof and having outwardly protruding sections 26 at spaced intervals about the periphery thereof. A number of cam rollers 28 are mounted for rotation on shafts 30 which are fixed relative to a stationary component. The cam rollers 28 are located so as to bear against the cam surfaces 24. Theprojections 26 of the cam surfaces of one rotary assembly are circumferentially spaced relative to the projections 20 of the other rotary assembly such that the cam rollers will not engage the projections of both cam surfaces simultaneously. In use, the shaft 20 rotates carrying with it the rotary assemblies 16 and the oscillating assemblies comes in contact with the rollers 28, the rotary assembly 26 is displaced longitudinally relative to the shaft 20. The longitudinal displacement of the rotary assembly 16 serves to release the locking rings which secures the rotary assembly and oscil- 18. When the cam surface 26 of one rotary assembly I lating assembly to one another when in electrical engagement. The return drive means then serves to reverse the direction of rotation of the oscillating assembly so as to return it to a predetermined fixed position relative to the stationary housing. During the time that one set of contacts is out of engagement, the other set remains in engagement. The second set of contacts will be disengaged when the protrusion 26 of the cam surface of the second set engages the roller 28 by which time the first set will be again locked in contact. When in use, as will be described hereinafter, the rotary assembly is electrically connected to electrical wiring extending through the hollow tube 20 while the oscillating assembly is connected to electrical wiring carried by a stationary housing or the like. The wiring connecting the oscillating assembly and the stationary housing does not become excessively wound during the rotational movement of the oscillating assembly and the extent of movement of the oscillating assembly can be limited by increasing the number of protrusions formed on the cam surface so that the direction of rotation of the oscillating assembly may be altered several times in the course of a single revolution of the shaft 20.

Referring now to FIG. 2 of the drawing, the reference numeral again refers to a rotary electrical joint according to an embodiment of this invention. The joint 10 is used to connect a rotating component 40 and a stationary component 42. The joint comprises a housing generally identified by the reference numeral 32. The housing 32 consists of a tubular side wall 34 and a pair of transversely extending end walls 36. One of the end walls 36 has a flange adapted to be secured to the stationary component 42.

The hollow shaft is connected to the rotating component 40 for rotation about the axis of the component. The junction 43 is carried by an end plate 44 which is clamped between the rotary component 40 and the shaft 20. The junction 43 is adapted to be connected to a conduit 44 which is electrically connected to the rotating component.

A pair of sleeves 46 are located towards opposite ends of the shaft 20 to support ball bearings 48 which serve to rotatably mount the shaft 20 in the end walls 36 of the housing so that the shaft 20 is free to rotate within the housing. A second pair of sleeves 50 are located on the shaft 20 inwardly from the first mentioned sleeves 46 as shown in FIG. 2. These sleeves provide a support for the oscillating assembly and compression spring as will be described hereinafter.

As previously indicated with reference to FIG. 1, the joint includes two sets of

contacts

12 and 14. The sets of contacts are identical to one another and consequently only one set will be described hereinafter.

As previously indicated, the set of contacts 12 comprises a rotary assembly 16 and an oscillating assembly 18. The rotary assembly 16 comprises a rotary contact support disc 52 which has a central passageway defined by an upwardly extending tubular portion 54. A pair of key ends 56 project inwardly from the support 52 through elongated passages formed in the sleeve 50 into elongated slots 58 formed in the shaft 20. The sleeve portion 56 is of'a sufficient diameter to fit in a close fitting sliding relationship over the sleeve 50 and the pin 56 is of a diameter to fit in a close fitting relationship within the slot 58 so as to permit longitudinal movement of the rotary assembly 16 relative to the shaft while rotatably driving the rotary assembly 16 with the shaft in use.

A coil spring 60 extends around the sleeve 50 and has one end located in a slot formed in the sleeve 50 and the other end located in the slot formed in the end of the sleeve portion 54 of the support 52. The immersion spring 60 serves to urge the rotary assembly 16 into engagement with the oscillating assembly 18 as will be described hereinafter.

The rotary assembly has a plurality of annular contact sup port rings 62 rotated at the peripheral edge of the support 54 and mounted one on top of the other. A plurality of rotary electrical contacts 64 project radially inwardly into the contact chamber 66 formed inwardly of the rings 62. The rings 62 are clamped together by clamping screws 68 which are threadably mounted in the support 52. A number of latch elements 70 are secured to the rotary assemblies by the mounting screw 68 so as to project inwardly therefrom to lock with the oscillating assembly as will be described hereinafter.

Each of the oscillating assemblies 18 comprises a support disc 72 which is rotatably mounted relative to the sleeve 50 by means of a ball bearing race 74. From FIG. 2 of the drawings, it will be seen that while the oscillating support 72 is mounted for rotation relative to the shaft 20, it is fixed against longitudinal movement relative to the shaft 20. A plurality of oscillating contact support rings 76 are mounted one on top of the other and serve to support oscillating contacts 78, which project radially outwardly into the contact chamber 66 formed between the rotary contact assembly and the shaft. A plurality of notches 80 are located on an outwardly projecting flange portion of each oscillating assembly. The notches 80 are adapted to receive the latch members 70 of the rotary assemblies 16.

As shown with reference to FIGS. 2 and 4 of the drawings, each of the oscillating assemblies is connected to the housing 32 by means of a coil spring 82. The inner end of the coil spring 82 is connected to the oscillating assembly 18 and the outer end of the coil spring is connected to the housing 32 in a manner such that when the shaft rotates in its operative direction of rotation, the coil spring is tightened such that the forces applied by the coil spring act in a direction opposite to the direction of rotation of the shaft 20.

Referring now to FIGS. 1, 2 and 3 of the drawings, it will be seen that the cam surface 24 extends around the periphery of the under side of the rotary assembly 16 and has three projections 26 extending outwardly therefrom. The projections 26 are spaced at 120 intervals about the peripheral edge. Three cam rollers 28 are mounted on three support shafts 30 which project inwardly from the housing 32 at 120 intervals. The shafts 30 are mounted on threaded supports 84 which are located in side passageways formed in the housing 32 so as to support the cam rollers in a fixed position relative to the housing. One rotary housing 16 is located relative to the other rotary housing such that the protrusions 26 of one are out of alignment with the protrusions 26 of the other so that the cam rollers will move the rotary assemblies out of contact with their oscillating assemblies at different times during the rotation about the axis ofthe shaft.

A stationary junction 42a is supported by a support bracket 86 in a position overlying the output passage 88 of the housing 32 so as to provide a junction for connection to a conduit 43a which is in electrical contact with the stationary component.

In the embodiment illustrated in FIG. 2, electrical wires 90 extend from the junction 43 to each of the oscillating assemblies so as to provide one wire in electrical connection with each of the electrical contacts of the oscilating assembly as shown at 92 in FIG. 2. The wires 90 are secured to the coil spring 82 so as to extend from their fixed position relative to the housing to the oscillating assembly. By arranging the wires in this manner, it is possible to permit the oscillating housing to move to and fro while controlling the movement of the connecting wires in such a way that they do not become entangled. It will be understood that in certain instances where only one conductor is required, the coil spring itself may act as a conductor without requiring additional wiring.

Fixed electrical wires 94 extend from the junction 422 into the hollow center of the shaft 20 to branch out through passages 96 formed in the shaft to extend into the'chamber formed between the shaft and the wall of the housing. The wires 94 are then formed to extend through passages 98 formed in the annular portion of the rotary support assembly. The wires 94 are then connected to a contact 64 of the rotary assembly 16. In the embodiment illustrated in FIG. 2 of the drawings, all of the ingoing electrical wires 94 are secured to a contact ring of the lower of the two rotary assemblies. Contact between the electrical contacts of one rotary assembly and the other rotary assembly is achieved by six electrical wires 100 which extend from one contact to the other through passageways 102 formed in the rotary assemblies.

. In order to control the extent of recycling of the oscillating contact assemblies when the locking mechanism is disengaged, a pin 83 is mounted on the upper edge 85 of the oscillating assembly (FIG. 5) and a small block 87 projects from the end wall 36 into the path of rotation of the pin 83. When the locking mechanism is released and the spring mechanism drives the oscillating housing in the direction of the arrow D, the rotational drive of the spring will continue until the pin 83 strikes a lug 87.

When the joint illustrated in FIG. 1 is in use, the drive shaft is rotatably driven by the drive means (not shown) which drives the rotating component 40 relative to the stationary component 42. Whereas in the embodiment shown in FIG. 1 the shaft is an integral part of the rotating component, the device of FIG. 2 has its own shaft which is connected to the shaft of the component. When the joint is in the position shown in FIG. 2, the upper set of contacts are in electrical engagement with one another and the latch 70 is operably located within the slot 80 so that the upper set of contacts are locked in engagement for rotation with the shaft 20. The lower set of contacts 14 are out of engagement due to the fact that the cam roller is at a point engaging the outwardly projecting portion of the cam track of the lower rotary assembly. When the lower assembly is in this disengaged position, the spring 82 serves to reverse the direction of rotation of the oscillating member so as to return it to a fixed position relative to the housing. When the oscillating assembly is returned to fixed position, the compression spring 60 urges the latch 70 into engagement with the next adjacent notch 80.

Further rotation of the shaft 20 will again tighten the spiral springs 82 until the protruding portion of the upper rotary cam comes into contact with a roller 28. The cam roller will elevate the rotary assembly so as to permit the oscillating assembly to return to its fixed position relative to the housing under the influence of the spiral spring 80. This procedure will be repeated at 120 intervals of rotation for each set of contacts.

An uninterrupted flow of current is achieved by connecting the rotary junction 42 to one of the rotary contact assemblies and by electrically connecting one rotary assembly to the other rotary assembly such that when one or other of the contacts is broken by the camming action, current will pass through the contacts which are unbroken.

While a number of the structural features of the embodiment disclosed in FIG. 2 are not essential to the operation of a joint according to the broad principles of this device, they do nevertheless contribute substantially to the practical value of the device. For example, the arrangement wherein the contacts are stacked one on top of the other with the oscillating contacts arranged within the contact chamber formed in the rotary contact assembly provides a very efficient use of the space provided within the housing, and it also permits a large number of contacts to be located within a limited space. In addition, the use of the latch and a complementary slot ensures that the contacts will be held out of contact by the action of the underside of the latch bearing against the upper surface of the oscillating contact during the recycling of the oscillating contact. This structure does not allow the electrical contacts to slide relative to one another so that frictional wear and radio noise as a result of the slipping of the contacts is eliminated. In addition, the spiral springs serve to provide convenient paths for the conductor wires and by securing the wires to the spiral springs by means of an adhesive, it is possible to permit the wires to flex in use while holding them in a controlled configuration.

These and other advantages of the structure of FIG. 1 will be apparent to those skilled in the art.

From the foregoing, it will be apparent that the present invention provides a simple and effective rotary electrical joint suitable for use in connecting the flat panels which support the solar cells of a spacecraft in use. Due to the fact that .the connection is maintained continuously and recycling takes place without requiring recycling of the shaft 20, it is possible to provide a continuous electrical connection between the solar cells and the spacecraft. The fact that the only structural component which has to be recycled is the oscillating contact, it is of considerable advantage in a spacecraft application as this eliminates the necessity of providing any mechanical drive means for rotatably driving the panels, in a direction opposite to their normal driven direction of rotation. Considerably less power is required in order to recycle the relatively small oscillating contacts than would be required in order to recycle the large flat panels which extend outwardly from a spacecraft. FIG. 6 of the drawings shows a typical spacecraft installation wherein the electrical joint may be used to connect the panel supporting shafts 1 10 to the spacecraft 112.

An alternative form of switch is illustrated in FIG. 7 of the drawings. In this drawing, the reference numerals correspond to the reference numerals used to identify like parts in FIG. 2 of the drawings. In this embodiment of the invention, there, is only one set of contacts which are identified by the reference numeral 12. The difference between the operation of this device and that illustrated in FIG. 2 is that when the contacts open, the flow of current from the rotating body to the stationary body will be interrupted. There are certain applications in which this type of interruption is not a serious drawback.

Various modifications of the illustrated apparatus will be apparent to those skilled in the art without departing from the scope of this invention. For example, the contacts may be made in the form of tapered ring contacts so as to mechani cally engage one another in a locked arrangement by reason of the interlocking tapers.

In a further modification, the complementary contacts may be in the form of a pair of fiat discs with a plurality of annular rings of contacts rather than the stacked contact assembly illustrated in FIG. 2.

What I claim as my invention is:

l. A rotary electrical joint comprising:

a. at least one rotary electrical contact means adapted to be secured to a rotating member for rotation therewith about an axis,

b. at least one oscillating electrical contact means mounted for movement to and fro in a predetermined arc about said axis to cooperate with said rotary contact to provide at least one pair of complementary contacts consisting of a rotary contact and an oscillating contact,

c. means for maintaining said pair of complementary contacts in electrical engagement during at least a portion of one revolution of said rotary contacts,

d. circuit breaker means for cyclically disengaging said complementary contacts,

e. return drive means driving said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means, and

f. releasable locking means for mechanically locking said complementaty contacts to one another to prevent slipping between the rotary and oscillating contacts, said locking means being released by said circuit breaker when said complementary contacts are disengaged to permit the return drive means to operate.

2. A rotary electrical joint comprising:

a. at least two rotary electrical contact means adapted to be secured to a rotating member for rotation therewith about an axis,

b. at least two oscillating electrical contact means mounted for movement to and fro in a predetermined are about said axis independently of one another to cooperate with said rotary contacts to provide at least two pairs of complementary contacts, each consisting of a rotary contact and an oscillating contact,

c. means for maintaining each pair of contacts in electrical engagement during at least a portion of one revolution of said rotary contacts,

d. circuit breaker means for cyclically disengaging one pair of contacts while the other pair remains in contact and the second mentioned pair of contacts while the first mentioned pair of contacts remain in contact,

e. return drive means for independently driving each of said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means, and

f. releasable locking means for mechanically locking the contacts of each pair of complementary contacts relative to one another to prevent rotary slipping between the retary contact and the oscillating contact of each pair, said locking means being releasable by said circuit breaker means when said complementary contacts of each pair of contacts are disengaged to permit the return drive means to operate.

3. A rotary electrical joint for connecting two components, one of which is to be mounted for rotation relative to the other, comprising:

a. a housing adapted to be secured to one of said components,

b, a chamber formed in said housing,

c. a hollow shaft rotatably mounted in said housing and extending into said chamber for rotation about a longitudinally extending axis,

. at least two rotary contact assemblies mounted for rotation on said shaft and spaced longitudinally relative to one another within said chamber,

e. at least two oscillating electrical contact means mounted for movement to and fro within said housing relative to said shaft in a predetermined are about said axis independently of one another, said oscillating contacts cooperating with said rotary contacts to provide at least two pairs of complementary contacts each consisting of a rotary contact and an oscillating contact, means for maintaining each pair of contacts in electrical engagement during at least a portion of one revolution of said rotary contacts,

f. circuit breaker means for cyclically disengaging one pair of contacts while the other pair remains in contact and the second pair of contacts while the first mentioned pair of contacts remain in contact,

return drive means for independently driving each of said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means, and

. releasable locking means for mechanically locking the contacts of each pair of complementary contacts relative to one another to prevent rotary slipping between the rotary contact and the oscillating contact of each pair, said locking means being releasable by said circuit breaker means when said complementary contacts of each pair of contacts are disengaged to permit the return drive means to operate.

4. A rotary electrical joint as claimed in claim 3 wherein said releasable locking means comprises latch means carried by each of said rotary contacts and complementary slot means formed in each of said oscillating contacts, said means for maintaining each pair of contacts in electrical engagement serving to urge said latch means into engagement with said slot means.

5. A rotary electrical joint as claimed in claim 3 wherein said means for maintaining each pair of contacts in electrical engagement comprises a pair of compression springs mounted coaxially with said shaft and reacting between said shaft and each of said electrical contact means.

6. A rotary electrical joint as claimed in claim 3 wherein said return drive means comprises coil spring means connecting each of said oscillating contact means to said housing, said coil spring means being biased to rotatably drive said oscillating assemblies in said direction opposite to the direction of rotation of the rotary contact means.

7. A rotary electrical joint as claimed in claim 6 including stop means coacting between said housing and each of said oscillating contact means to limit the rotation of said oscillating contact means in the direction of rotation of said coil spring bias.

8. A rotary joint as claimed in claim 3 wherein each of said rotary contact means is in the form of a contact assembly comprising:

a. a rotary contact support disc having a central passage therein to receive said shaft, said disc being keyed to said shaft for longitudinal movement relative to said shaft and rotation with said shaft,

a plurality of contact support rings mounted adjacent the outer peripheral edge of said rotary disc and arranged one on top of the other in a direction towards the opposite ends of said housing, said rotary contact support rings having inner peripheral edges spaced radially outwardly from said shaft to form an annular contact chamber therebetween,

. rotary electrical contacts extending radially inwardly from each of said rotary contact supportrings into said contact chamber, each of said oscillating electrical contact means consisting of an assembly comprising,

an oscillating contact support disc mounted on said shaft for rotation relative to said shaft about said axis and secured against longitudinal movement relative to said shaft,

e. a plurality of oscillating support rings mounted on said oscillating support disc and extending longitudinally inwardly of said housing and oscillating electrical contacts extending radially outwardly from each of said oscillating contact support rings, each of said oscillating contact assemblies being mounted for rotation about said shaft with said oscillating contact support rings extending into a contact chamber of a rotary contact assembly such that the radially extending electrical contacts of the rotary assembly and the radially extending electrical contacts of the oscillating assembly overlap one another.

9. A rotary joint as claimed in claim 8 wherein said circuit breaker means comprises:

a. at least one cam roller mounted for rotation about a transverse axis and fixed to said housing to extend into said chamber,

b. each of said rotary support discs having an annular cam track surface extending inwardly from the peripheral edge thereof, said cam surfaces overlying said cam roller means and having at least one protruding section extending outwardly from the plane of the remainder of the cam surface, the protruding sections of one cam surface being circumferentially spaced relative to the protruding sections of the other cam surface such that said cam roller will displace one of said rotary contact members longitudinally out of contact with its complementary oscillating assembly when one of said protruding sections of said cam surface engages said roller means, and the other rotary contact will be moved out of engagement with the other oscillating assembly when the protruding sections of the cam surface of the other rotary assembly is engaged by said cam means such that one or other of the rotary assemblies will at all times remain in contact with an oscillating assembly.

10. A rotary joint as claimed in claim 3 including electrical conductor means for electrically connecting each of the electrical contact means of one of the rotary contacts with an electrical contact means of the other rotary contact.

11. A rotary joint as claimed in claim 6 wherein said shaft is formed with a plurality of passageways extending therethrough and opening into said chamber and further including a first electrical junction means secured to said shaft for rotation therewith and a second electrical junction means secured to said housing, first electrical contact means extending from said first junction means through said hollow shaft and through said passage means formed in said hollow shaft into said chamber to communicate between each rotary contact and the terminal of said junction means, and electrical conductor means extending coextensively with respect to said coil spring means to communicate between each of said'oscillating contact means and a terminal of said junction carried by said housing and additional electrical conductor means communicating between electrical contacts of one of said rotary assemblies and the corresponding electrical contact of the other of said rotary assemblies whereby one electrical contact of each assembly is connected to a single terminal of the rotary junction means.

12. A rotary electrical joint comprising:

d. circuit breaker means for cyclically moving said complementary contacts away from one another in a direction substantially normal to the direction of rotation of said contacts to disengage said complementary contacts, and

e. return drive means driving said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means.

13. A rotary electrical joint comprising:

d. circuit breaker means for cyclically disengaging one pair of contacts while the other pair remains in contact and the second mentioned pair of contacts while the first mentioned pair of contacts remain in contact, said circuit breaker means including means for removing the complementary contacts of each pair of contacts away from one another in a direction substantially normal to the direction of rotation of said contacts to disengage the contacts while permitting slipping to occur between the contacts, return drive means for independently driving each of said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means.

14. A rotary electrical joint for connecting two components, one of which is to be mounted for rotation relative to the other, comprising:

a. a housing adapted to be secured to one of said components,

b. a chamber formed in said housing,

d. at least two rotary contact assemblies mounted for rotation on said shaft and spaced longitudinally relative to one another within said chamber,

e. at least two oscillating electrical contact means mounted formovement to and fro within said housing relative to said shaft in a predetermined are about said axis independently of one another, said oscillating contacts cooperating with said rotary contacts to provide at least two pairs of complementary contacts each consisting of a rotary contact and an oscillating contact, means for maintaining each pair of contacts in electrical engagement during at least a portion of one revolution of said rotary contacts,

f. circuit breaker means for cyclically disengaging one pair of contacts while the other pair remains in contact and the second pair of contacts while the first mentioned pair of contacts remain in contact, said circuit breaker means including means for moving the complementary contacts of each pair of contacts away from one another in a direction substantially normal to the direction of rotation of said contacts to disengage the contacts while permitting slipping to occur between the contacts,

g. return drive means for independently driving each of said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means.

15. A rotary electrical joint as claimed in claim 14 including releasable locking means for mechanically locking the contacts of each pair of complementary contacts relative to one another to prevent rotary slipping between the rotary contact and the oscillating contact of each pair, said locking means being releasable by said circuit breaker means when said complementary contacts of each pair of contacts are disengaged to permit the return drive means to operate.

16. A rotary electrical joint as claimed in claim 14 wherein said means for maintaining each pair of contacts in electrical engagement comprises a pair of compression springs mounted coaxially with said shaft and reacting between said shaft and each of said electrical contact means.

17. A rotary electrical joint as claimed in claim 14 wherein said return drive means comprises coil spring means connecting each of said oscillating contact means to said housing, said coil spring means being biased to rotatably drive said oscillating assemblies in said direction opposite to the direction of rotation of the rotary contact means.

18. A rotary electrical joint as claimed in claim 17 including stop means coacting between said housing and each of said oscillating contact means to limit the rotation of said oscillating contact means in the direction of rotation of said coil spring bias.

19. A rotary joint as claimed in claim 14 wherein each of said rotary contact means is in the form of a contact assembly comprising:

b. a plurality of contact support rings mounted adjacent the outer peripheral edge of said rotary disc and arranged one on top of the other in a direction towards the opposite ends of said housing, said rotary contact support rings having inner peripheral edges spaced radially outwardly from said shaft to form an annular contact chamber therebetween,

c. rotary electrical contacts extending radially inwardly from each of said rotary contact support rings into said contact chamber, each of said oscillating electrical contact means consisting of an assembly comprising:

d. an oscillating contact support disc mounted on said shaft for rotation relative to said shaft about said axis and secured against longitudinal movement relative to said shaft,

20. A rotary joint as claimed in claim 19 wherein said circuit breaker means comprises:

a. at least one cam roller mounted for rotation about a tions of the other cam surface such that said cam roller will displace one of said rotary contact members longitudinally out of contact with its complementary oscillating transverse axis and fixed to said housing to extend into assembly when one of said protruding sections of said id h mbe 5 cam surface engages said roller means, and the other roeach of said rotary support discs having an annular cam tary Contact will be moved out of engagement with the t a k rfa e extending i a dl f h i h other oscillating assembly when the protruding sections edge thereof, said cam surfaces overlying said cam roller cam surface of the other rotary assembly 15 8 8 means and having at least one protruding section extendy Salt} means P that 3 P other of h rotary t ins outwardly f the plane f the remainder f the cam 10 semblles will at all times remain in contact with an oscilsurface, the protruding sections of one cam surface being latmg assembly' circumferentially spaced relative to the protruding sec-

Claims

1. A rotary electrical joint comprising: a. at least one rotary electrical contact means adapted to be secured to a rotating member for rotation therewith about an axis, b. at least one oscillating electrical contact means mounted for movement to and fro in a predetermined arc about said axis to cooperate with said rotary contact to provide at least one pair of complementary contacts consisting of a rotary contact and an oscillating contact, c. means for maintaining said pair of complementary contacts in electrical engagement during at least a portion of one revolution of said rotary contacts, d. circuit breaker means for cyclically disengaging said complementary contacts, e. return drive means driving said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means, and f. releasable locking means for mechanically locking said complementaty contacts to one another to prevent slipping between the rotary and oscillating contacts, said locking means being released by said circuit breaker when said complementary contacts are disengaged to permit the return drive means to operate.

2. A rotary electrical joint comprising: a. at least two rotary electrical contact means adapted to be secured to a rotating member for rotation therewith about an axis, b. at least two oscillating electrical contact means mounted for movement to and fro in a predetermined arc about said axis independently of one another to cooperate with said rotary contacts to provide at least two pairs of complementary contacts, each consisting of a rotary contact and an oscillating contact, c. means for maintaining each pair of contacts in electrical engagement during at least a portion of one revolution of said rotary contacts, d. circuit breaker means for cyclically disengaging one pair of contacts while the other pair remains in contact and the second mentioned pair of contacts while the first mentioned pair of contacts remain in contact, e. return drive means for independently driving each of said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means, and f. releasable locking means for mechanically locking the contacts of each pair of complementary contacts relative to one another to prevent rotary slipping between the rotary contact and the oscillating contact of each pair, said locking means being releasable by said circuit breaker means when said complementary contacts of each pair of contacts are disengaged to permit the return drive means to operate.

3. A rotary electrical joint for connecting two components, one of which is to be mounted for rotation relative to the other, comprising: a. a housing adapted to be secured to one of said components, b. a chamber formed in said housing, c. a hollow shaft rotatably mounted in said housing and extending into said chamber for rotation about a longitudinally extending axis, d. at least two rotary contact assemblies mounted for rotation on said shaft and spaced longitudinally relative to one another within said chamber, e. at least two oscillating electrical contact means mounted for movement to and fro within said housing relative to said shaft in a predetermined arc about said axis independently of one another, said oscillating contacts cooperating with said roTary contacts to provide at least two pairs of complementary contacts each consisting of a rotary contact and an oscillating contact, means for maintaining each pair of contacts in electrical engagement during at least a portion of one revolution of said rotary contacts, f. circuit breaker means for cyclically disengaging one pair of contacts while the other pair remains in contact and the second pair of contacts while the first mentioned pair of contacts remain in contact, g. return drive means for independently driving each of said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means, and h. releasable locking means for mechanically locking the contacts of each pair of complementary contacts relative to one another to prevent rotary slipping between the rotary contact and the oscillating contact of each pair, said locking means being releasable by said circuit breaker means when said complementary contacts of each pair of contacts are disengaged to permit the return drive means to operate.

8. A rotary joint as claimed in claim 3 wherein each of said rotary contact means is in the form of a contact assembly comprising: a. a rotary contact support disc having a central passage therein to receive said shaft, said disc being keyed to said shaft for longitudinal movement relative to said shaft and rotation with said shaft, b. a plurality of contact support rings mounted adjacent the outer peripheral edge of said rotary disc and arranged one on top of the other in a direction towards the opposite ends of said housing, said rotary contact support rings having inner peripheral edges spaced radially outwardly from said shaft to form an annular contact chamber therebetween, c. rotary electrical contacts extending radially inwardly from each of said rotary contact support rings into said contact chamber, each of said oscillating electrical contact means consisting of an assembly comprising, d. an oscillating contact support disc mounted on said shaft for rotation relative to said shaft about said axis and secured against longitudinal movement relative to said shaft, e. a plurality of oscillating support rings mounted on said oscillating support disc and extending longitudinally inwardly of said housing and oscillating electrical contacts extending radially outwardly from each of said oscillating contact support rings, each of said oscillating contact assemblies being mounted for rotation about said shaft with said oscillating contact support rings extending into a contact chamber of a rotary contact assembly such that the radially extending electrical contacts of the rotAry assembly and the radially extending electrical contacts of the oscillating assembly overlap one another.

9. A rotary joint as claimed in claim 8 wherein said circuit breaker means comprises: a. at least one cam roller mounted for rotation about a transverse axis and fixed to said housing to extend into said chamber, b. each of said rotary support discs having an annular cam track surface extending inwardly from the peripheral edge thereof, said cam surfaces overlying said cam roller means and having at least one protruding section extending outwardly from the plane of the remainder of the cam surface, the protruding sections of one cam surface being circumferentially spaced relative to the protruding sections of the other cam surface such that said cam roller will displace one of said rotary contact members longitudinally out of contact with its complementary oscillating assembly when one of said protruding sections of said cam surface engages said roller means, and the other rotary contact will be moved out of engagement with the other oscillating assembly when the protruding sections of the cam surface of the other rotary assembly is engaged by said cam means such that one or other of the rotary assemblies will at all times remain in contact with an oscillating assembly.

11. A rotary joint as claimed in claim 6 wherein said shaft is formed with a plurality of passageways extending therethrough and opening into said chamber and further including a first electrical junction means secured to said shaft for rotation therewith and a second electrical junction means secured to said housing, first electrical contact means extending from said first junction means through said hollow shaft and through said passage means formed in said hollow shaft into said chamber to communicate between each rotary contact and the terminal of said junction means, and electrical conductor means extending coextensively with respect to said coil spring means to communicate between each of said oscillating contact means and a terminal of said junction carried by said housing and additional electrical conductor means communicating between electrical contacts of one of said rotary assemblies and the corresponding electrical contact of the other of said rotary assemblies whereby one electrical contact of each assembly is connected to a single terminal of the rotary junction means.

12. A rotary electrical joint comprising: a. at least one rotary electrical contact means adapted to be secured to a rotating member for rotation therewith about an axis, b. at least one oscillating electrical contact means mounted for movement to and fro in a predetermined arc about said axis to cooperate with said rotary contact to provide at least one pair of complementary contacts consisting of a rotary contact and an oscillating contact, c. means for maintaining said pair of complementary contacts in electrical engagement during at least a portion of one revolution of said rotary contacts, d. circuit breaker means for cyclically moving said complementary contacts away from one another in a direction substantially normal to the direction of rotation of said contacts to disengage said complementary contacts, and e. return drive means driving said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means.

13. A rotary electrical joint comprising: a. at least two rotary electrical contact means adapted to be secured to a rotating member for rotation therewith about an axis, b. at least two oscillating electrical contact means mounted for movement to and fro in a predetermined arc about said axis independently of one another to cooperate with said rotary contacts to provide at least two pairs of complementary contacts, each consisting of a rotary contact and an oscillating contact, c. means for maintaining each pair of contacts in electrical engagement during at least a portion of one revolution of said rotary contacts, d. circuit breaker means for cyclically disengaging one pair of contacts while the other pair remains in contact and the second mentioned pair of contacts while the first mentioned pair of contacts remain in contact, said circuit breaker means including means for removing the complementary contacts of each pair of contacts away from one another in a direction substantially normal to the direction of rotation of said contacts to disengage the contacts while permitting slipping to occur between the contacts, e. return drive means for independently driving each of said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means.

14. A rotary electrical joint for connecting two components, one of which is to be mounted for rotation relative to the other, comprising: a. a housing adapted to be secured to one of said components, b. a chamber formed in said housing, c. a hollow shaft rotatably mounted in said housing and extending into said chamber for rotation about a longitudinally extending axis, d. at least two rotary contact assemblies mounted for rotation on said shaft and spaced longitudinally relative to one another within said chamber, e. at least two oscillating electrical contact means mounted for movement to and fro within said housing relative to said shaft in a predetermined arc about said axis independently of one another, said oscillating contacts cooperating with said rotary contacts to provide at least two pairs of complementary contacts each consisting of a rotary contact and an oscillating contact, means for maintaining each pair of contacts in electrical engagement during at least a portion of one revolution of said rotary contacts, f. circuit breaker means for cyclically disengaging one pair of contacts while the other pair remains in contact and the second pair of contacts while the first mentioned pair of contacts remain in contact, said circuit breaker means including means for moving the complementary contacts of each pair of contacts away from one another in a direction substantially normal to the direction of rotation of said contacts to disengage the contacts while permitting slipping to occur between the contacts, g. return drive means for independently driving each of said oscillating contact means in a direction opposite to the direction of rotation of said rotary contact means when disengaged from said rotary contact means by said circuit breaker means.

19. A rotary joint as claimed in claim 14 wherein each of said rotary contact means is in the form of a contact assembly comprising: a. a rotary contact support disc having a central passage therein to receive said shaft, said disc being keyed to said shaft for longitudinal movement relative to said shaft and rotation with said shaft, b. a plurality of contact support rings mounted adjacent the outer peripheral edge of said rotary disc and arranged one on top of the other in a direction towards the opposite ends of said housing, said rotary contact support rings having inner peripheral edges spaced radially outwardly from said shaft to form an annular contact chamber therebetween, c. rotary electrical contacts extending radially inwardly from each of said rotary contact support rings into said contact chamber, each of said oscillating electrical contact means consisting of an assembly comprising: d. an oscillating contact support disc mounted on said shaft for rotation relative to said shaft about said axis and secured against longitudinal movement relative to said shaft, e. a plurality of oscillating support rings mounted on said oscillating support disc and extending longitudinally inwardly of said housing and oscillating electrical contacts extending radially outwardly from each of said oscillating contact support rings, each of said oscillating contact assemblies being mounted for rotation about said shaft with said oscillating contact support rings extending into a contact chamber of a rotary contact assembly such that the radially extending electrical contacts of the rotary assembly and the radially extending electrical contacts of the oscillating assembly overlap one another.

20. A rotary joint as claimed in claim 19 wherein said circuit breaker means comprises: a. at least one cam roller mounted for rotation about a transverse axis and fixed to said housing to extend into said chamber, b. each of said rotary support discs having an annular cam track surface extending inwardly from the peripheral edge thereof, said cam surfaces overlying said cam roller means and having at least one protruding section extending outwardly from the plane of the remainder of the cam surface, the protruding sections of one cam surface being circumferentially spaced relative to the protruding sections of the other cam surface such that said cam roller will displace one of said rotary contact members longitudinally out of contact with its complementary oscillating assembly when one of said protruding sections of said cam surface engages said roller means, and the other rotary contact will be moved out of engagement with the other oscillating assembly when the protruding sections of the cam surface of the other rotary assembly is engaged by said cam means such that one or other of the rotary assemblies will at all times remain in contact with an oscillating assembly.