US 4,046,235 AGranted

Automatic load brake

AssigneeWestern Gear Corporation

InventorDonald P. Shutt

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Abstract

The disclosure is of an improvement of automatic load brakes, of the type generally and generically known as a Weston disk brake, as used, for example, in braking a hoisting drum adapted for reeling in and reeling out a cable suspending a load. The frictional brake disks and plates, while lowering the load, experience a feed-back torque from the load. Means are provided for feeding only a proportional part of the total energy so fed back to only a fraction of the brake plates, whereby to instantly break these loose for relative rotation in response to lowering inputs. By this feature, response is instantaneous, and no further provisions are required to break away or accelerate the plates. Improvements are also disclosed by which, when feed-back is controlling the application of the brake, the usual oscillatory application of the brake, i.e., chatter, is stabilized and virtually eliminated. Another feature is continuous oil cooling of the brake disks and rings during the duty cycle of the brake (reeling out) and also during the off-duty cycle of the brake (reeling in), thus lowering the average temperature of the cooling oil. This is accomplished by an integral gear pump which pumps cooling oil continuously, and automatically reverses position to accomplish this as the direction of cable travel reverses.

Claims23

Dependent claims

An automatic load brake of the Weston class, using a drive motor, and adapted for coupling to a load imposed as a torque, comprising:

an external casing,
an axially restrained output drive rotor journalled for rotation on a fixed axis relative to said casing, and adapted for coupling to a load applied as a torque,
an input drive rotor journalled for rotation in said casing about said fixed axis, said input rotor adapted for rotary drive by said motor, at least one of said rotors being adapted for axial travel along said fixed axis,
said output drive rotor and said input drive rotor having interengaging circularly disposed ramp formations on opposed faces thereof which interact to move said input drive rotor axially away from said output drive rotor in relative rotation in one direction of said rotors, and which allow said input drive rotor to return axially toward said output drive rotor in relative rotation in the opposite direction of said rotors,
opposed, longitudinally splined hubs on said rotors,
a plurality of brake plates, at least one of said plates being splined on said hub of said output rotor and at least one of said plates being splined on said hub of said input rotor,
means on the side of said input drive rotor, opposite from the side thereof having said ramps, providing a plane brake pressure surface facing toward said brake plates,
means on said output drive rotor providing a plane brake reaction surface facing toward said plane brake pressure surface,
friction brake disks intervening in spaces between, and engageable with, said brake plates, and intervening also between and engageable with the end brake plates and said brake pressure reaction surfaces,
disk guide means engaging and coacting with guide formations on said friction disks for guiding them generally axially;
a one-way rotary holding means for reacting between said disk guide means and said casing to permit rotation of said friction disks and brake plates, in the incoming direction of rotation of said rotors, and to lock said disk guide means and friction disks and plates against rotation relative to said casing in the outgoing direction of rotation of said rotors;
and
means for urging said rotors to return axially toward each other in response to said opposite rotation of said rotors.

10 more elements

An automatic load brake of the Weston class, using a drive motor, and adapted for coupling to a load imposed as a torque, comprising:

an external casing,
an axially restrained output drive rotor journalled for rotation on a fixed axis relative to said casing, and adapted for coupling to a load applied as a torque,
an input drive rotor journalled for rotation in said casing about said axis and adapted for axial travel therealong, said input rotor adapted for rotary drive by said motor,
at least one of said rotors being adapted for axial travel along said fixed axis,
said output rotor and said input drive rotor having interengaging circularly disposed ramp formations on opposed faces thereof which interact to move said input drive rotor axially away from said output drive rotor in relative rotation in one direction of said rotors, and which allow said input drive rotor to return axially toward said output drive rotor in relative rotation in the opposite direction of said rotors,
opposed, longitudinally splined hubs on said rotors,
a plurality of brake plates, at least one of said plates being splined on said hub of said output rotor and at least one of said plates being splined on said hub of said input rotor,
means on the side of said input drive rotor opposite from the side thereof having said ramps, providing a plane brake pressure facing toward said brake plates,
means on said output drive rotor providing a plane brake reaction surface facing said plane brake pressure surface,
friction brake disks intervening in spaces between, and engageable with, said brake plates, and intervening also between and engageable with the end brake plates and said brake pressure and reaction surfaces,
disk guide means for engaging and coacting with guide formations on said friction disks for guiding them generally axially,
a one-way rotary holding means for reacting between said disk guide means and said casing to permit rotation of said friction disks and brake plates in the incoming direction of rotation of said rotors, and to lock said disk guide means and friction disks and plates against rotation relative to said casing in the outgoing direction of rotation of said rotor;
and
means for urging said input drive rotors to return axially toward each other in response to said opposite rotation of said rotors.

11 more elements

An automatic load brake of the Weston class, using a drive motor, and adapted for coupling to a load imposed as a torque, comprising:

an external casing,
an axially restrained output drive rotor journalled for rotation on a fixed axis relative to said casing, and adapted for coupling to a load applied as a torque,
an input drive motor journalled for rotation in said casing about said fixed axis, said input rotor adapted for rotary drive by said motor, at least one of said rotors being adapted for axial travel along said fixed axis,
means for moving said rotors apart axially in response to relative rotation in one direction, which allows said rotors to return axially toward each other in response to relative rotation in the opposite direction,
a plurality of brake plates, at least one of said plates being attached to said output rotor for rotation therewith, and at least one of said plates being attached to said input rotor for rotation therewith,
means on said rotors for applying brake pressure to said brake plates,
friction brake disks intervening in spaces between, and engageable with, said brake plates,
a one-way rotary holding means for reacting between said disk guide means and said casing to permit rotation of said friction disks and brake plates in the incoming direction of rotation of said rotors, and to lock said disk guide means and friction disks and plates against rotation relative to said casing in the outgoing direction of rotation of said rotors;
and
means for urging said rotors to return axially toward each other in response to said opposite rotation of said rotors.

7 more elements

An automatic load brake of the Weston class, using a drive motor, and adapted for coupling to a load imposed as a torque, comprising:

an external casing,
an axially restrained output drive rotor journalled for rotation on a fixed axis relative to said casing, and adapted for coupling to a load applied as a torque,
an input drive rotor journalled for rotation in said casing about said fixed axis, said input rotor adapted for rotary drive by said motor, at least one of said rotors being adapted for axial travel along said fixed axis,
means for moving said rotors apart axially in response to relative rotation in one direction, which allows said rotors to return axially toward each other in response to relative rotation in the opposite direction,
a plurality of brake plates, each attached to one of said rotors for rotation therewith,
means on said input drive rotor for applying brake pressure to said brake plates,
friction brake disks intervening in spaces between, and engageable with, said brake plates,
a one-way rotary holding means for reacting between said plates and said casing to permit rotation of said plates relative to said casing in the incoming direction of rotation of said rotors, and for holding said plates against rotation relative to said casing in the outgoing direction,
means for urging said rotors to return axially toward each other in response to said opposite rotation of said rotors;
oil pump means for supplying oil to said disks and plates, and
passage means for supplying oil from said pump means towards the centers of said disks and plates, thereby allowing oil to flow radially outwardly, to provide a thin film of oil across the working surfaces of the plates.

8 more elements

Dependencies are inferred from the claim text.