Articulated friction unit assembly for brake or clutch use

Claim 2

In a brake or clutch structure, a friction unit assembly adapted to be selectively engaged with a drum comprising: first and second arcuate shoe sections pivotally interconnected in longitudinal end to end alignment and movable as a unit into engagement with a drum surface upon an operating force being applied to said assembly, each of said shoe sections having an arcuately curved face thereof adapted to receive friction material; lever arm means secured to said first shoe section and extending past the adjoining ends of said shoe sections to said second shoe section with an abutment stop adjacent said second shoe section; arc diameter limiting means carried by said second shoe section disposed generally radially inwardly of said abutment stop and engageable with said abutment stop to limit the maximum arc to which said shoe sections may pivotally move relative to each other, said second shoe section further having biasing means engaging said lever arm means in a direction to urge said shoe sections to said maximum arc while enabling said shoe sections to conform closely to a lesser arc that the drum distorts to under forces produced in braking.

Claim 3

In a brake or clutch structure, a friction unit assembly adapted to be selectively engaged with a drum comprising: first and second arcuate shoe sections pivotally interconnected in longitudinal end to end alignment and movable as a unit into engagement with a drum surface upon an operating force being applied to said assembly, each of said shoe sections having an arcuately curved face thereof adapted to receive friction material; at least one web on each shoe section extending perpendicularly to and radially inward of said arcuately curved face of the section; lever arm means secured to the web on said first shoe section and extending past the adjoining ends of said shoe sections to lie adjacent the web of said second shoe section, said lever arm means having an abutment stop adjacent said second shoe section web; an arc diameter limiting means secured to the web of said second shoe section generally radially inwardly of said abutment stop, said limiting means carrying adjusting means engageable with said abutment stop to limit the maximum arc to which said shoe sections may pivotally move relative to each other, the web of said second shoe section further mounting biasing means engaging said lever arm means to urge said shoe sections to said maximum arc.

Claim 4

In a brake or clutch structure, a friction unit assembly adapted to be selectively engaged with a drum comprising: first and second arcuate shoe sections pivotally interconnected in longitudinal end to end alignment and movable as a unit into engagement with a drum surface upon an operating force being applied to said assembly, each of said shoe sections having an arcuately curved face thereof adapted to receive friction material; at least one web on each shoe section extending perpendicularly to and radially inward of said arcuately curved face of the section; lever arm means secured to the web on said first shoe section and extending past the adjoining ends of said shoe sections to lie adjacent the web of said second shoe section, said lever arm means having an abutment stop adjacent said second shoe section web; an arc diameter limiting means secured to the web of said second shoe section generally radially inwardly of said abutment stop, said limiting means carrying adjusting means engageable with said abutment stop to limit the maximum arc to which said shoe sections may pivotally move relative to each other, the web of said second shoe section further mounting biasing means engaging said lever arm means to urge said shoe sections to said maximum arc.

Claim 5

In a brake or clutch structure, a friction unit assembly adapted to be selectively engaged with a drum comprising: first and second arcuate shoe sections pivotally interconnected in longitudinal end to end alignment and movable as a unit into engagement with a drum surface upon an operating force being applied to said assembly, each of said shoe sections having an arcuately curved face thereof adapted to receive friction material; at least one web on each shoe section extending perpendicularly to and radially inward of said arcuately curved face of the section; lever arm means secured to the web on said first shoe section and extending across the adjoining ends of said shoe sections to lie adjacent the web of said second shoe section, said lever arm means having an abutment stop adjacent said second shoe section web; an arc diameter limiting member on the web of said second shoe section generally radially inwardly of said abutment stop and engageable with said abutment stop to limit the maximum arc to which said shoe sections may pivotally move relative to each other; and biasing means on the web of said second shoe section engaging said lever arm means to urge said shoe sections to said maximum arc.

Claim 6

In a brake or clutch structure, a friction unit assembly adapted to be selectively engaged with a drum comprising: first and second arcuate shoe sections pivotally interconnected in longitudinal end to end alignment and movable as a unit into engagement with a drum surface upon an operating force being applied to said assembly, each of said shoe sections having an arcuately curved face thereof adapted to receive friction material; at least one web on each shoe section extending perpendicularly to and radially inward of said arcuately curved face of the section; lever arm means secured to the web on said first shoe section and extending across the adjoining ends of said shoe sections to lie adjacent the web of said second shoe section, said lever arm means having an abutment stop adjacent said second shoe section web; an arc diameter limiting member on the web of said second shoe section generally radially inwardly of said abutment stop and engageable with said abutment stop to limit the maximum arc to which said shoe sections may pivotally move relative to each other; and biasing means on the web of said second shoe section engaging said lever arm means to urge said shoe sections to said maximum arc.

Claim 7

A friction unit assembly as recited in claim 3 wherein each shoe section has a pair of parallel webs and said lever arm means, arc diameter limiting member and biasing means are nested between said parallel webs.

Claim 8

A friction unit assembly as recited in claim 4 wherein the pivotal interconnection between said shoe sections comprises a levering pin received in generally semicircular notches in the abutting ends of the shoe sections at their juncture and said pin is captured to retain said sections pivotally interconnected by being engaged in bores in said lever arm means.

Claim 9

A friction unit assembly as recited in claim 4 wherein said lever arm means comprises lever arms secured to the inner faces of said parallel webs of said first shoe section to extend along the inner faces of the parallel webs of said second shoe section, and said abutment stop is connected between the ends of said lever arms.

Claim 10

A friction unit assembly as recited in claim 6 wherein said arc diameter limiting member extends between the inner faces of the parallel webs on said second shoe section, and an adjusting screw threadably engages said limiting member and said abutment stop to adjustably determine the maximum arc.

Claim 11

A friction unit assembly as recited in claim 3 wherein each shoe section has a single central web carrying said lever arm means, arc diameter limiting member and biasing means.

Claim 12

A friction unit assembly as recited in claim 8 wherein said lever arm means comprises lever arms secured to the outer faces of said single web of said first shoe section to extend along the outer faces of the single web of said second shoe section, and each of said lever arms carries an abutment stop.

Claim 13

A friction unit assembly as recited in claim 9 wherein said arc diameter limiting member extends laterally from the outer faces of said single web of said second shoe section, and each lateral extension of said member has an adjusting screw threadably engaged therewith to cooperate with the abutment stop on each lever arm in adjustably determining the maximum arc.

Claim 14

A friction unit assembly as recited in claim 3 wherein said arc diameter limiting member carries an adjusting screw which engages with said abutment stop to adjustably determine said maximum arc.

Claim 15

A friction unit assembly as recited in claim 3 wherein said lever arm means has a spring rest ledge adjacent said second shoe section web, and said biasing means comprises a flat spring biased to exert a generally radially inward force against said spring rest ledge.

Claim 16

A friction unit assembly as recited in claim 12 wherein said flat spring is secured to said arc diameter limiting member to impart the biasing force, and said limiting member carries an adjusting screw which engages with said abutment stop to adjustably determine said maximum arc.

Claim 17

A friction unit assembly as recited in claim 13 wherein said adjusting screw locates said flat spring on said arc diameter limiting member, and nut means cooperates with said screw to clamp said spring on said limiting member and fix said screw in its adjusted position for maximum arc determination.