Dock leveler operating apparatus

Claim 2

A dock leveler for bridging a gap between a loading dock and a carrier bed comprising: a base plate to be attached to the loading dock; a center plate having first and second opposite edges, said first edge pivotably connected to said base plate for pivotal movement in rearward and forward directions between a full rearward position and a forward position; a lip plate having first and second opposite edges, the first edge of the lip plate pivotably connected to the second edge of the center plate for pivotal movement between a retracted position in which the lip plate forms an acute angle with the center plate, a stored position in which the lip plate forms a substantially right angle with the center plate and a bridging position in which the lip plate is substantially coplanar with and forms an extension of the center plate; lever means pivotably connected to the center plate, said lever means pivoting the center plate to the full rearward position upon movement in the rearward direction to a first position, the lip plate pivoting to the retracted position during the pivoting of the center plate to the full rearward position; and lip extension means for selectively pivoting the lip plate either toward the bridging position or to the stored position in response to forward movement of the lever means at times when the center plate is in the full rearward position, said forward movement of the lever means pivoting the center plate toward the forward position.

Claim 3

The dock leveler as recited in claim 1, wherein the lever means comprises an elongated member pivotably connected to the center plate, a manually operated lever and a connecting member having a first end connected to the base plate and a second end connected to the elongated member for limiting the pivotal movement of said lever and said elongated member.

Claim 4

The dock leveler as recited in claim 2, wherein the connecting member comprises a chain.

Claim 5

The dock leveler as recited in claim 2, wherein the connecting member comprises a U-shaped bar dimensioned to slidably receive the elongated member.

Claim 6

The dock leveler as recited in claim 2, wherein the connecting member comprises a closed loop and wherein the elongated member includes means slidably engaged in said loop.

Claim 7

The dock leveler as recited in claim 1, wherein the lip extension means includes an extension stop member disposed on the base plate and an extension member having a first end pivotably connected to the lip plate and a free second end, the free second end being engaged with the extension stop member at times when the lip plate is selected to pivot toward the bridging position.

Claim 8

The dock leveler as recited in claim 6, wherein the lip extension means includes cocking means attached to the lever means and the lip plate for engaging the free second end of the extension member on the extension stop member in response to a distinct movement of the lever means.

Claim 9

The dock leveler as recited in claim 7, wherein the cocking means includes a cocking stop member disposed on the lever means and a cocking arm having a first end pivotably connected to the lip plate and a free second end operative to engage the cocking stop member for engaging the free second end of the extension member on the extension stop member.

Claim 10

The dock leveler as recited in claim 8, wherein the engagement between the cocking arm and the cocking stop member causes the lip plate to pivot counterclockwise from the retracted position for raising the second edge of the lip plate relative to the loading dock.

Claim 11

The dock leveler as recited in claim 6, wherein the extension stop member includes an angled portion and the extension member disengages from said angled portion in a shear action when the center plate reaches a predetermined pivotal position.

Claim 14

The apparatus as recited in claim 11, wherein the lever means comprises an elongated member to be pivotably connected to the center plate, a manually operated lever and a connecting member having a first end to be connected to the base plate and a second end connected to the elongated member for limiting the pivotal movement of the lever and the elongated member.

Claim 15

The apparatus as recited in claim 12, wherein the connecting member comprises a chain.

Claim 16

The apparatus as recited in claim 12, wherein the connecting member comprises a U-shaped bar dimensioned to slidably receive the elongated member.

Claim 17

The apparatus as recited in claim 12, wherein the connecting member comprises a closed loop and wherein the elongated member includes means slidably engaged in said loop.

Claim 18

The apparatus as recited in claim 11, wherein the lip extension means includes an extension stop member to be disposed on the base plate and an extension member having a first end to be pivotally connected to the lip plate and a free second end, the free second end being engaged with the extension stop member at times when the lip plate is selected to pivot toward the bridging position.

Claim 19

The apparatus as recited in claim 16, wherein the lip extension means includes cocking means to be attached to the lever means and the lip plate for engaging the free second end of the extension member on the extension stop member in response to a distinct movement of the lever means.

Claim 20

The apparatus as recited in claim 17, wherein the cocking means includes a cocking stop member disposed on the lever means and a cocking arm having a first end to be pivotally connected to the lip plate and a free second end operative to engage the cocking stop member for engaging the free second end of the extension member on the extension stop member.

Claim 21

The dock leveler as recited in claim 18, wherein the engagement between the cocking arm and the cocking stop member causes the lip plate to pivot counterclockwise from the retracted position for raising the second edge of the lip plate relative to the loading dock.

Claim 22

The apparatus as recited in claim 16, wherein the extension stop member includes an angled portion and the extension member disengages from said angled portion in a sear action when the center plate reaches a predetermined pivotal position.

Claim 23

A dock leveler for bridging a gap between a loading dock and a carrier bed comprising: a base plate to be attached to the loading dock; a center plate having first and second opposite edges, said first edge pivotably connected to said base plate for pivotal movement in rearward and forward directions between a rearward position and a forward position; a lip plate having first and second opposite edges, the first edge of the lip plate pivotably connected to the second edge of the center plate for pivotal movement between a retracted position in which the lip plate forms an acute angle with the center plate, a stored position in which the lip plate forms a substantially right angle with the center plate, and a bridging position in which the lip plate is substantially coplanar with and forms an extension of the center plate; a manually operated lever; an operating tube for slidably receiving said lever; an elongated member having first and second spaced opposite ends, said operating tube being fixedly secured to the elongated member intermediate said first and second ends, said first end of said elongated member being pivotably connected to the center plate; a connecting member having first and second opposite ends, a first end being pivotably connected to the base plate and said second end being connected to the elongated member for limiting the pivotal movement of the lever and the elongated member, said elongated and connecting members operative to pivot the center plate to the rearward position upon movement of the lever in the rearward direction to a first position, the lip plate pivoting to the retracted position during the pivoting of the center plate to the rearward position; lip extension means for selectively pivoting the lip plate either toward the bridging position or to the stored position in response to forward movement of the lever at times when the center plate is in the rearward position, said forward movement of the lever pivoting the center plate toward the forward position, the lip extension means including an extension stop member disposed on the base plate and an extension member having a first end pivotably connected to the lip plate and a free second end, the free second end being engaged with the extension stop member at times when the lip plate is selected to pivot toward the bridging position; cocking means including a cocking stop member disposed on the elongated member and a cocking arm, said cocking arm having a first end pivotably connected to the lip plate and a free second end operative to engage the cocking stop member for engaging the free second end of the extension member on the extension stop member in response to a distinct movement of the lever, the engagement between the cocking stop member and the second end of the cocking arm causing the lip plate to pivot counterclockwise from the retracted position for raising the second edge of the lip plate relative to the loading dock.

Claim 24

A dock leveler for bridging a gap between a loading dock and a carrier bed comprising: a base plate to be attached to the loading dock; a center plate having first and second opposite edges, said first edge pivotably connected to said base plate for pivotal movement in rearward and forward directions between a rearward position and a forward position; a lip plate having first and second opposite edges, the first edge of the lip plate pivotably connected to the second edge of the center plate for pivotal movement between a retracted position in which the lip plate forms an acute angle with the center plate, a stored position in which the lip plate forms a substantially right angle with the center plate, and a bridging position in which the lip plate is substantially coplanar with and forms an extension of the center plate; a manually operated lever; an operating tube for slidably receiving said lever; an elongated member having first and second spaced opposite ends, said operating tube being fixedly secured to the elongated member intermediate said first and second ends, said first end of said elongated member being pivotably connected to the center plate; a connecting member having first and second opposite ends, a first end being pivotably connected to the base plate and said second end being connected to the elongated member for limiting the pivotal movement of the lever and the elongated member, said elongated and connecting members operative to pivot the center plate to the rearward position upon movement of the lever in the rearward direction to a first position, the lip plate pivoting to the retracted position during the pivoting of the center plate to the rearward position; lip extension means for selectively pivoting the lip plate either toward the bridging position or to the stored position in response to forward movement of the lever at times when the center plate is in the rearward position, said forward movement of the lever pivoting the center plate toward the forward position, the lip extension means including an extension stop member disposed on the base plate and an extension member having a first end pivotably connected to the lip plate and a free second end, the free second end being engaged with the extension stop member at times when the lip plate is selected to pivot toward the bridging position; cocking means including a cocking stop member disposed on the elongated member and a cocking arm, said cocking arm having a first end pivotably connected to the lip plate and a free second end operative to engage the cocking stop member for engaging the free second end of the extension member on the extension stop member in response to a distinct movement of the lever, the engagement between the cocking stop member and the second end of the cocking arm causing the lip plate to pivot counterclockwise from the retracted position for raising the second edge of the lip plate relative to the loading dock.

Claim 25

The dock leveler as recited in claim 21, wherein the extension stop member includes an angled portion and the extension member disengages from said angled portion in a sear action when the center plate reaches a predetermined pivotal position.

Claim 28

The method as recited in claim 23, further comprising the step of permitting the extension member to disengage from the extension stop member when the center plate is at a predetermined pivotal position, the disengagement of the extension member from the extension stop member creating a sear action.