Electromagnetic clutch-brake devices

Claim 2

A magnetic particle clutch-brake device comprising: a rotatable shaft having a single magnetic coupling member mounted thereon for rotation therewith, said member comprising a hollow cylindrical portion that is coaxial with said shaft and an annular portion that extends radially of said cylindrical portion; a brake unit including a stationary magnetic armature and one of said portions of said coupling member; a clutch unit including a rotor and a stator and the other of said portions of said coupling member, said rotor being rotatable with respect to said stator and said stator being stationary relative to said armature; a first drive coil for establishing magnetic flux through said armature and said one portion of said coupling member, said first drive coil being held stationary with respect to said armature; a second drive coil for establishing magnetic flux through said rotor and stator and said other portion of said coupling member, said second drive coil being held stationary with respect to said stator; said coupling member disposed so as to provide a first space between said one portion thereof and said armature and a second space between said other portion thereof and said rotor, said spaces being filled with magnetic particles; and sealing means for substantially preventing said magnetic particles from escaping from said space.

Claim 3

A device as set forth in claim 1 wherein said spaces communicate with each other to form a single large space.

Claim 4

The beacon of claim 1 wherein said timer means includes means for periodically blanking the output of said modulator means so that each period of the output signal produced thereby includes a third interval of silence, whereby said acoustic projector is caused to transmit a periodic acoustic signal in which each period successively comprises a first interval of the first frequency, a second interval of the first frequency modulated by the second frequency and a third interval of silence.

Claim 5

Signal modulation apparatus for use in an acoustic beacon comprising: a first oscillator for producing a first signal having a frequency f1; a second oscillator for producing a second signal having a frequency f2; a modulator connected to said first and second oscillators so as to receive the first and second signals therefrom, said modulator being operable to produce a modulated signal whose predominant frequency components are f1 - f2 and f1 + f2; and timer means connected to said modulator for periodically interrupting modulation of the first signal, whereby said modulator produces a periodic output signal, each period of which comprises a first interval of signal whose frequency is f1 followed by a second interval of signal whose predominant frequency components are f1 - f2 and f1 + f2.

Claim 6

Signal modulation apparatus for use in an acoustic beacon comprising: a first oscillator for producing a first signal having a frequency f1; a second oscillator for producing a second signal having a frequency f2; a modulator connected to said first and second oscillators so as to receive the first and second signals therefrom, said modulator being operable to produce a modulated signal whose predominant frequency components are f1 - f2 and f1 + f2; and timer means connected to said modulator for periodically interrupting modulation of the first signal, whereby said modulator produces a periodic output signal, each period of which comprises a first interval of signal whose frequency is f1 followed by a second interval of signal whose predominant frequency components are f1 - f2 and f1 + f2.

Claim 7

A device as set forth in claim 1 wherein: said brake unit includes said annular portion of said member; and said clutch unit includes said cylindrical portion of said member.

Claim 8

A device as set forth in claim 1 wherein: said brake unit includes said cylindrical portion of said member; and said clutch unit includes said annular portion of said member.

Claim 9

The apparatus of claim 3 wherein said timer means is operable to periodically blank the signal produced by said modulator so that each period of the modulated signal includes a third interval of silence.

Claim 10

A device as set forth in claim 1 wherein said coupling member is L-shaped in longitudinal section, and said cylindrical portion forms the longest leg of said L-shaped section.

Claim 11

A device as set forth in claim 1 wherein said annular portion is at one end of said cylindrical portion.

Claim 12

A device according to claim 1 wherein the outer diameter of said annular portion is greater than the outer diameter of said cylindrical portion.

Claim 13

A device as set forth in claim 1 wherein said annular portion is positioned substantially orthogonally with respect to said axis of rotation.

Claim 14

A device as set forth in claim 2 wherein said sealing means comprises only two sealing members for completely sealing said space.

Claim 15

A device as set forth in claim 9 wherein one of said sealing members engages said rotor and the other of said sealing members engages said armature.

Claim 16

A device as set forth in claim 9 wherein each of said sealing members comprises a compressible washer.

Claim 17

A device as set forth in claim 9 wherein each of said sealing members comprises a compressible washer with one of said washers being pressed between a portion of said rotor and a portion of said armature and the other of said washers is pressed between a portion of said rotor, said shaft, and said coupling member.

Claim 18

In a combination magnetic particle clutch-brake device having rotatable input and output shafts, a brake unit for braking one of said shafts including a stationary magnetic armature, a clutch unit for clutching said shafts together including a rotor which forms part of one of said shafts and a stator within which said rotor is rotatably mounted, said stator being Stationary with respect to said armature, and first and second energizeable coils for generating magnetic flux for operating said brake and clutch units respectively, said coils being stationary with respect to said armature and stator, the improvements comprising: a single magnetic coupling member mounted on the other of said shafts for rotation therewith, said coupling member comprising an annular portion and a cylindrical portion, said armature and said rotor being spaced from and cooperating with said coupling member so as to define a space therebetween, magnetic particles in said space, said first coil and one portion of said coupling member being disposed so that when energized said first coil will establish one magnetic flux path via said particles through said armature and said one portion of said coupling member for braking said other shaft, and said second coil and the other portion of said coupling member being disposed so that when energized said second coil will establish another magnetic flux path via said particles through said rotor and stator and said other portion of said coupling member so as to clutch said shafts to one another, and means for sealing said space to substantially prevent said magnetic particles from escaping from said space.

Claim 19

In a combination magnetic particle clutch-brake device having rotatable input and output shafts, a brake unit for braking one of said shafts including a stationary magnetic armature, a clutch unit for clutching said shafts together including a rotor which forms part of one of said shafts and a stator within which said rotor is rotatably mounted, said stator being Stationary with respect to said armature, and first and second energizeable coils for generating magnetic flux for operating said brake and clutch units respectively, said coils being stationary with respect to said armature and stator, the improvements comprising: a single magnetic coupling member mounted on the other of said shafts for rotation therewith, said coupling member comprising an annular portion and a cylindrical portion, said armature and said rotor being spaced from and cooperating with said coupling member so as to define a space therebetween, magnetic particles in said space, said first coil and one portion of said coupling member being disposed so that when energized said first coil will establish one magnetic flux path via said particles through said armature and said one portion of said coupling member for braking said other shaft, and said second coil and the other portion of said coupling member being disposed so that when energized said second coil will establish another magnetic flux path via said particles through said rotor and stator and said other portion of said coupling member so as to clutch said shafts to one another, and means for sealing said space to substantially prevent said magnetic particles from escaping from said space.

Claim 20

A combination magnetic particle clutch and brake device comprising: a rotatable shaft having a single magnetic coupling member mounted thereon for rotation therewith, said member comprising a hollow cylindrical portion that is coaxial with said shaft and an annular portion that extends radially of said cylindrical portion; a brake unit including a stationary magnetic armature and one of said portions of said coupling member, said armature having a bull-nosed portion; a clutch unit including a rotor and a stator and the other of said portions of said coupling member, said stator being stationary relative to said armature and said rotor having a bull-nosed portion; a first drive coil for establishing magnetic flux through said armature and said one portion of said coupling member; a second drive coil for establishing magnetic flux through said rotor and stator and said other portion of said coupling member; said coupling member disposed so as to provide a first space between said one portion thereof and said armature and a second space between said other portion thereof and said rotor, said spaces being filled with magnetic particles; and two sealing washers, one of said washers being compressed against a portion of said stator by said bull-nosed portion of said rotor and the other of said washers being pressed against a portion of said shaft and a portion of said member by said bull-nosed portion of said armature, said sealing washers serving to completely seal said space to prevent the escape of said magnetic particles from said space.

Claim 21

A combination magnetic particle clutch and brake device comprising: a rotatable shaft having a single magnetic coupling member mounted thereon for rotation therewith, said member comprising a hollow cylindrical portion that is coaxial with said shaft and an annular portion that extends radially of said cylindrical portion; a brake unit including a stationary magnetic armature and one of said portions of said coupling member, said armature having a bull-nosed portion; a clutch unit including a rotor and a stator and the other of said portions of said coupling member, said stator being stationary relative to said armature and said rotor having a bull-nosed portion; a first drive coil for establishing magnetic flux through said armature and said one portion of said coupling member; a second drive coil for establishing magnetic flux through said rotor and stator and said other portion of said coupling member; said coupling member disposed so as to provide a first space between said one portion thereof and said armature and a second space between said other portion thereof and said rotor, said spaces being filled with magnetic particles; and two sealing washers, one of said washers being compressed against a portion of said stator by said bull-nosed portion of said rotor and the other of said washers being pressed against a portion of said shaft and a portion of said member by said bull-nosed portion of said armature, said sealing washers serving to completely seal said space to prevent the escape of said magnetic particles from said space.

Claim 22

A magnetic particle clutch-brake device comprising: a housing; an input shaft and an output shaft each rotatably supported within said housing; a clutch unit for clutching said shafts together, said clutch unit including a magnetic rotor on and rotatable with one of said shafts and means in said housing defining a magnetic stator in spaced surrounding relation to said rotor, said rotor having a pair of spaced poles; a brake unit for braking the other of said shafts, said brake unit including means in said housing defining a stationary magnetic core with a pair of spaced poles; a magnetic coupling member carried by and rotatable with said other shaft, said coupling member comprising a first portion extending between and spaced from the poles of said rotor and a second portion extending between and spaced from the poles of said core; magnetic particles in the spaces between said coupling member and the poles of said rotor and said core; sealing means for preventing escape of said magnetic particles from said spaces; a first coil mounted to said stator for establishing magNetic flux through said stator, said rotor poles, said first portion of said coupling member and said particles so as to clutch said shafts to one another; and a second coil mounted to said core for establishing magnetic flux through said core poles, said second portion of said coupling member and said particles so as to brake said other shaft.

Claim 23

A magnetic particle clutch-brake device comprising: a housing; an input shaft and an output shaft each rotatably supported within said housing; a clutch unit for clutching said shafts together, said clutch unit including a magnetic rotor on and rotatable with one of said shafts and means in said housing defining a magnetic stator in spaced surrounding relation to said rotor, said rotor having a pair of spaced poles; a brake unit for braking the other of said shafts, said brake unit including means in said housing defining a stationary magnetic core with a pair of spaced poles; a magnetic coupling member carried by and rotatable with said other shaft, said coupling member comprising a first portion extending between and spaced from the poles of said rotor and a second portion extending between and spaced from the poles of said core; magnetic particles in the spaces between said coupling member and the poles of said rotor and said core; sealing means for preventing escape of said magnetic particles from said spaces; a first coil mounted to said stator for establishing magNetic flux through said stator, said rotor poles, said first portion of said coupling member and said particles so as to clutch said shafts to one another; and a second coil mounted to said core for establishing magnetic flux through said core poles, said second portion of said coupling member and said particles so as to brake said other shaft.

Claim 24

A magnetic particle clutch-brake device according to claim 15 wherein the members of one of said pairs of poles are spaced axially of said housing and the members of the other of said pairs of poles are spaced radially of said housing.

Claim 25

A magnetic particle clutch-brake device according to claim 15 wherein one shaft is hollow and said other shaft is rotatably mounted within said one shaft.

Claim 26

A device as set forth in claim 14 wherein: said bull-nosed portions each has a substantially rounded end which bears against the corresponding washer with sufficient force to seal said space against particle escape while permitting said rotor to rotate. As is apparent from the preceding discussion, the applicant''s unique acoustic beacon produces (1) a short pulse at a single frequency, (2) an interval of signal at two precisely spaced single frequency components, and (3) an interval of silence. This signal has been found to have characteristics which make it particularly well suited for use in a highly accurate acoustic position reference system. Although a specific embodiment of apparatus for producing the specified signal is shown for illustrative purposes, other embodiments which do not depart from the applicant''s contemplation and teaching will be apparent to those skilled in the art. The applicant does not wish to be limited to the disclosed embodiment, but only by the terms of the appended claims. I claim: