Low inertia clutch and brake system having safety operation features

A low inertia clutch and brake system comprising:

• a rotatable shaft,
• a low speed clutch assembly including friction clutch surfaces mounted about said shaft,
• a high speed clutch assembly including friction clutch surfaces mounted about said shaft and spaced from said low speed clutch assembly,
• a brake assembly disposed between said low and high speed clutch assemblies and including friction surfaces mounted about said shaft, said brake assembly normally biased to an engaged position to prevent rotation of said shaft,
• a stationary housing disposed about said brake assembly,
• first and second piston means slidably mounted in said housing on opposite sides of said brake assembly, each of said means being selectively actuated in response to fluid pressure to disengage said actuated means from said brake assembly and to engage a selected one of said clutch assemblies,
• means for selectively applying fluid pressure to one of said piston means in order to disengage said actuated means from said brake assembly and to engage one of said clutch assemblies, and
• means for interconnecting said piston means to permit said piston means to simultaneously engage said brake assembly and to prevent simultaneous engagement of both said clutch assemblies.

In a low inertia clutch-brake assembly wherein a brake is located between a rotating shaft and is disposed between two clutch assemblies, the combination comprising:

• a pair of non-rotating annular pistons disposed about said shaft on opposite sides of the brake,
• a plurality of biasing members attached to each of said pistons and disposed radially outwardly from said brake,
• springs disposed in association with said biasing members for exerting a biasing force against said biasing members to normally bias said pistons toward one another to normally engage the brake,
• means for admitting pressurized fluid against a selected one of said pistons to disengage said actuated piston from the brake and to engage one of the clutch assemblies, and
• means for interconnecting said pistons to permit both of said pistons to simultaneously engage the brake and preventing simultaneous engagement of both of the clutch assemblies.

A clutch and brake system comprising:

• a rotatable shaft,
• a low speed clutch assembly mounted about said shaft,
• a high speed clutch assembly mounted about said shaft and spaced from said low speed clutch assembly,
• a brake assembly disposed between said low and high speed clutch assemblies and including means for normally preventing rotation of said shaft,
• first and second means for selectively actuating either of said low and high speed clutch assemblies while disengaging only the actuated means from said brake assembly in order to rotate said shaft at a predetermined speed,
• means for sensing a predetermined magnitude of wear of said brake assembly, and
• means operable in response to said sensing means to indicate undesirable brake wear.

A clutch and brake system comprising:

• a rotatable shaft,
• a low speed clutch assembly mounted about said shaft,
• a high speed clutch assembly mounted about said shaft and spaced from said low speed clutch assembly,
• a brake assembly disposed between said low and high speed clutch assemblies and including means for normally preventing rotation of said shaft and two non-rotating pistons,
• means for selectively actuating either of said low and high speed clutch assemblies while disengaging said brake assembly in order to rotate said shaft at a predetermined speed,
• means disposed between said pistons for detecting a predetermined amount of wear of said brake assembly by sensing the distance between said pistons and including a plunger operated air switch for being actuated when said pistons move within a predetermined distance to one another, and
• means operable in response to said sensing means to indicate undesirable brake wear.

A low inertia clutch and brake system comprising:

• a rotatable shaft,
• a low speed clutch assembly including friction clutch surfaces mounted about said shaft,
• a high speed clutch assembly including friction clutch surfaces mounted about said shaft and spaced from said low speed clutch assembly,
• a brake assembly disposed between said low and high speed clutch assemblies and including friction surfaces mounted about said shaft, said brake assembly normally biased to an engaged position to prevent rotation of said shaft,
• a stationary housing disposed about said brake assembly,
• pistons slidably mounted in said housing on opposite sides of said brake assembly and operable in response to fluid pressure to be selectively disengaged from said brake assembly and to engage a selected one of said clutch assemblies,
• means for sensing the temperature of at least one of said pistons, and
• means operable in response to detection of a predetermined temperature level by said sensing means to generate an overheating alarm signal.

A clutch and brake system comprising:

• a rotatable shaft,
• a low speed clutch assembly including friction clutch surfaces mounted about said shaft,
• a high speed clutch assembly including friction clutch surfaces mounted about said shaft and spaced from said low speed clutch assembly,
• a brake assembly disposed between said low and high speed clutch assemblies and including friction surfaces mounted about said shaft, said brake assembly normally engaged to prevent rotation of said shaft,
• a stationary housing disposed about said brake assembly and engaging outer peripheries of ones of said friction surfaces, said housing having a plurality of lateral apertures annularly spaced around said housing,
• first and second annular non-rotating pistons disposed about said shaft and laterally slidable in said housing,
• said pistons having piston surfaces disposed radially outwardly of said housing and having brake engaging surfaces for abutting the sides of said brake assembly disposed radially inwardly from said piston surfaces,
• a first plurality of rigid biasing members connected at one end to said first piston and extending through alternate ones of said apertures in said housing,
• a second plurality of rigid biasing members connected at one end to said second piston and extending through the remaining alternate ones of said apertures in said housing,
• springs disposed about said biasing members within said apertures in said housing for biasing said pistons toward one another for normally causing said brake assembly to be engaged,
• means in said housing for directing pressurized fluid to a selected one of said piston surfaces to move one of said pistons to engage one of said clutch assemblies and to disengage said actuated piston from said brake assembly, and
• means for interconnecting said first and second pistons to prevent simultaneous engagement of both of said clutch assemblies and to permit simultaneous engagement of said first and second pistons with said brake assembly.