Dockboard assembly

Claim 2

A dockboard assembly comprising: support means, ramp means pivotally connected at a first end thereof to said support means for movement between raised and lowered positions and extending to a second end, lip means pivotally connected to said second end of said ramp means for pivotal movement between an extended cantilevered position and a pendent position, a cam rotatably connected to said ramp means, lift means reacting between said support means and said cam for pivoting said ramp means upwardly from any position in which said ramp means is disposed, said cam being rotated by reaction between said ramp and said lift means as said ramp pivots, releasable hold-down means for normally preventing said ramp means from being pivoted upwardly by said lift means and operable to allow said ramp means to be pivoted upwardly by said lift means, lip linkage means for pivoting said lip means toward said extended position in response to rotational movement of said cam, latching means movable to a latched position for supporting said lip means in an extended latched position and operably connected to said lip linkage means and engageable by said cam at a position spaced from the connection thereof to said lip linkage means for movement by said cam to said latched position, said latching means free falls by gravity from said latched position when said lip means is pivoted upwardly from said extended latched position after said cam is rotated out of engagement with said latching means.

Claim 3

An assembly as set forth in claim 1 including control means operatively connected to said lip means for releasing said hold-down means in response to pivotal movement of said lip means toward said pendent position to allow said ramp means to pivot upwardly.

Claim 4

An assembly as set forth in claim 2 wherein said control means is attached to said lip linkage means and is engageable with said hold-down means for releasing the latter.

Claim 5

An assembly as set forth in claim 3 wherein said control means includes at least one control pawl pivotally connected to said lip linkage and depending therefrom.

Claim 6

An assembly as set forth in claim 4 wherein said latching means includes a latch link pivotally connected at a first end to said lip linkage means and having an upwardly opening recess therein, an abutment disposed on said ramp means for engaging said recess, said latch link engageable by said cam for upward movement thereby to said latched position where said abutment is disposed in said recess.

Claim 7

An assembly as set forth in claim 5 wherein said latching means further includes a resilient member disposed between said cam and said latch link foR allowing continued rotation of said cam after said cam has moved said latch link to said latched position.

Claim 8

An assembly as set forth in claim 6 wherein said lift means includes a lift arm pivotally connected to said support means at a first end thereof, a rotatable cam follower disposed on the second end of said lift arm for engaging said cam, and biasing means attached at one end thereof to said lift arm and attached at the other end thereof to one of said support means and said ramp means at a position adjacent the pivotal connection between said ramp means and said support means for urging said lift arm to pivot upwardly, said biasing means being sufficient to pivot said ramp means upwardly from any position upon release of said hold-down means; a mount suspended from said ramp means and rotatably supporting said cam, said abutment comprising a pin extending laterally from said mount; said lip linkage means including first and second telescoping links urged apart by at least one spring, said first link being pivotally connected to said lip means, a guide link pivotally connected to said mount at one end and pivotally connected to said second link at the other end, said cam having a notch for engaging the pivotal connection between said guide link and said second link for raising said lip means toward said extended position, said latch link being pivotally connected to said second link at the pivotal connection between said guide link and said second link, said control pawl being pivotally connected to said first link, stop means extending from said first link for limiting pivotal movement of said control pawl; said hold-down means includes a rod pivotally connected to said support means, a cylinder disposed about said rod, a spring disposed within said cylinder and reacting between said cylinder and said rod for urging said rod into said cylinder, an elongated ratchet bar pivotally connected to said ramp means, guide plates extending from said cylinder, said ratchet bar being slidably retained between said guide plates, a ratchet pawl rotatably connected to said guide plates and normally engaging said ratchet bar to prevent upward pivotal movement of said ramp means, said ratchet bar and said ratchet pawl having coacting ratchet teeth for preventing upward pivotal movement of said ramp means and allowing downward pivotal movement of said ramp means while engaged, a lever connected to said ratchet pawl for moving said ratchet pawl out of engagement with said ratchet bar for releasing said hold-down means, said control pawl being engageable with said lever for disengaging said ratchet pawl from said ratchet bar, manually actuatable means connected to said lever for manually releasing said hold-down means.

Claim 9

A dockboard assembly comprising: support means, ramp means pivotally connected at a first end thereof to said support means and extending to a second end, lip means pivotally connected to said second end of said ramp means for movement between a pendent position and an extended cantilevered position, a cam rotatably connected to said ramp means, lift means reacting between said support means and said cam for urging said ramp means to pivot upwardly, lip linkage means for pivoting said lip means toward said extended position, latching means movable to a latched position for supporting said lip means in an extended latched position and operably connected to said lip linkage means and engageable by said cam at a position spaced from the connection thereof to said lip linkage means for movement by said cam to said latched position, said latching means including a latch link pivotally connected at a first end to said lip linkage means and having an upwardly opening recess therein, an abutment disposed on said ramp means for engaging said recess, said latch link engageable by said cam for upward movement thereby to said latched position where said abutment is disposed in said recess.

Claim 10

A dockboard assembly comprising: support means, ramp means pivotally connected at a first end thereof to said support means and extending to a second end, lip means pivotally connected to said second end of said ramp means for movement between a pendent position and an extended cantilevered position, a cam rotatably connected to said ramp means, lift means reacting between said support means and said cam for urging said ramp means to pivot upwardly, lip linkage means for pivoting said lip means toward said extended position, latching means movable to a latched position for supporting said lip means in an extended latched position and operably connected to said lip linkage means and engageable by said cam at a position spaced from the connection thereof to said lip linkage means for movement by said cam to said latched position, said latching means including a latch link pivotally connected at a first end to said lip linkage means and having an upwardly opening recess therein, an abutment disposed on said ramp means for engaging said recess, said latch link engageable by said cam for upward movement thereby to said latched position where said abutment is disposed in said recess.

Claim 11

An assembly as set forth in claim 8 wherein said latching means further includes a rEsilient member disposed between said cam and said latch link for allowing continued rotation of said cam after said cam has moved said latch link to said latched position.

Claim 12

A dockboard assembly comprising: support means, ramp means pivotally connected at a first end thereof to said support means and extending to a second end, lift means for pivoting said ramp upwardly, releasable holding means for allowing and preventing said ramp from being pivoted upwardly by said lift means, a lip pivotally connected to said second end of said ramp for pivotal movement between an extended cantilevered position and a pendent position, lip linkage means for pivoting said lip means toward said extended position, and control means supported by said lip linkage means for automatically releasing said hold-down means in response to pivotal movement of said lip means toward said pendent position to allow said ramp means to pivot upwardly.

Claim 13

A dockboard assembly comprising: support means, ramp means pivotally connected at a first end thereof to said support means and extending to a second end, lift means for pivoting said ramp upwardly, releasable holding means for allowing and preventing said ramp from being pivoted upwardly by said lift means, a lip pivotally connected to said second end of said ramp for pivotal movement between an extended cantilevered position and a pendent position, lip linkage means for pivoting said lip means toward said extended position, and control means supported by said lip linkage means for automatically releasing said hold-down means in response to pivotal movement of said lip means toward said pendent position to allow said ramp means to pivot upwardly.

Claim 14

An assembly as set forth in claim 10 including latching means movable to a latched position for supporting said lip means in an extended latched position and operably connected to said lip linkage means and automatically movable from said latched position when said lip means is pivoted upwardly from said extended latched position.

Claim 15

An assembly as set forth in claim 11 wherein said control means includes at least one control pawl pivotally connected to said lip linkage and depending therefrom for engaging said hold-down means as said lip means pivots toward said pendent position after said latching means automatically moves from said latched position.

Claim 16

An assembly as set forth in claim 10 wherein said lip linkage means is pivotally connected to said lip means at a first end and extends rearwardly to a second end which is moved forwardly to raise said lip means in response to upward pivotal movement of said ramp means by said lift means.