Tailgate lift mechanism

Claim 2

In a tailgate lift for vehicles of the type having a bed with a tailgate opening for receiving loads, in which said lift has a fixed frame, has a platform, has linkage for movably connecting said platform to said frame and has power-operated means for moving said platform from ground level to bed level, the improving comprising: separate power-operated means on said frame for controlling movement of the platform from bed level to an upright tailgate-closing position, an element pivoted to said fixed frame, a fluid pressure operated ram having one end pivotally connected to the fixed frame and having its other end pivotally connected to said pivoted element to swing the latter, and a connecting element pivoted at one end to said pivotal element and at its other end to said linkage, said connecting element having an intermediate knee pivot which is movable over center with respect to the pivotal connection for said pivoted element and with respect to the pivotal connection with said linkage.

Claim 3

In a tailgate lift for vehicles of the type having a bed with a tailgate opening for receiving loads, in which said lift has a frame, has a platform, has linkage for movably connecting said platform to said frame and has power-operated means for moving said platform from ground level to bed level, the improvement comprising: separate power-operated means on said frame for controlling movement of the platform from bed level to an upright tailgate-closing position, said separate power-operated means including a knee pivot movable to an over-center position when the platform is in upright position to mechanically lock the platform in said tailgate-closing position, said tailgate-controlling linkage including a first element pivoted to the frame and having an extension, and a connecting element pivoted at one end to said extension to provide a knee action and at its other end to said linkage, and the knee action pivot being movable over center with respect to the pivotal connection for said element having the extension and with respect to the pivotal connection with said liNkage.

Claim 4

In a tailgate lift for vehicles of the type having a bed with a tailgate opening for receiving loads, in which said lift has a frame, has a platform, has linkage for movably connecting said platform to said frame and has power-operated means for moving said platform from ground level to bed level, the improvement comprising: separate power-operated means on said frame for controlling movement of the platform from bed level to an upright tailgate-closing position, said separate power-operated means including a knee pivot movable to an over-center position when the platform is in upright position to mechanically lock the platform in said tailgate-closing position, said tailgate-controlling linkage including a first element pivoted to the frame and having an extension, and a connecting element pivoted at one end to said extension to provide a knee action and at its other end to said linkage, and the knee action pivot being movable over center with respect to the pivotal connection for said element having the extension and with respect to the pivotal connection with said liNkage.

Claim 5

A tailgate lift as claimed in claim 2 in which the first pivoted element having an extension is a bell crank lever.

Claim 6

A tailgate lift as claimed in claim 2 in which the power-operated means includes a fluid pressure operated ram connected to the frame, and in which the first pivoted element is a bell crank lever having one extension to which the ram is pivotally connected and having another extension which is pivotally connected to the connecting element.

Claim 7

In a tailgate lift for vehicles of the type having a bed with a tailgate opening for receiving loads, in which said lift has a frame, has a platform, has linkage for movably connnecting said platform to said frame and has power-operated means for moving said platform from ground level to bed level, the improvement comprising: separate power-operated means on said frame for controlling movement of the platform from bed level to an upright tailgate-closing position, said separate power-operated means including a knee pivot movable to an over-center position when the platform is in upright position to mechanically lock the platform in said tailgate-closing position, the separate power-operated means comprising a fluid pressure operated ram, a bell crank lever pivoted to the lift frame and having one extension pivotally connected to the ram and having a second extension, a connecting rod pivotally connected at one end to said second extension and at its other end to said linkage, the pivot which is connected to the second extension being movable to an over-center position with respect to the pivot for the bell crank and with respect to the pivotal connection with the linkage when the platform is in upright position to mechanically lock the platform in said tailgate-closing position.

Claim 8

In a tailgate lift for vehicles of the type having a bed with a tailgate opening for receiving loads, in which said lift has a frame, has a platform, has linkage for movably connnecting said platform to said frame and has power-operated means for moving said platform from ground level to bed level, the improvement comprising: separate power-operated means on said frame for controlling movement of the platform from bed level to an upright tailgate-closing position, said separate power-operated means including a knee pivot movable to an over-center position when the platform is in upright position to mechanically lock the platform in said tailgate-closing position, the separate power-operated means comprising a fluid pressure operated ram, a bell crank lever pivoted to the lift frame and having one extension pivotally connected to the ram and having a second extension, a connecting rod pivotally connected at one end to said second extension and at its other end to said linkage, the pivot which is connected to the second extension being movable to an over-center position with respect to the pivot for the bell crank and with respect to the pivotal connection with the linkage when the platform is in upright position to mechanically lock the platform in said tailgate-closing position.

Claim 9

A tailgate lift as claimed in claim 5 in which the bell crank lever includes a shaft pivotally connected to the frame, and in which said bell crank extensions are rigid with said shaft but spaced from each other axially of the shaft.

Claim 10

In a tailgate lift for vehicles of the type having a bed with a tailgate opening for receiving loads, in which said lift has a frame, has a platform, has linkage for movably connecting said platform to said frame and has power-operated means for moving said platform from ground level to bed level, the improvement comprising: separate power-operated means on said frame for controlling movement of the platform from bed level to an upright tailgate-closing position, said separate power-operated means comprising: a crank arm pivoted to the lift frame, means for causing pivotal movement of said crank arm, a connecting rod pivotally connected at one end to said crank arm and at its other end to said linkage, the pivot which is connected to said crank arm being movable to an over-center position with respect to the pivot for the crank arm and with respect to the pivotal connection with the linkage when the platform is in an upright position to mechanically lock the platform in said tailgate-closing position.

Claim 11

In a tailgate lift for vehicles of the type having a bed with a tailgate opening for receiving loads, in which said lift has a frame, has a platform, has linkage for movably connecting said platform to said frame and has power-operated means for moving said platform from ground level to bed level, the improvement comprising: separate power-operated means on said frame for controlling movement of the platform from bed level to an upright tailgate-closing position, said separate power-operated means comprising: a crank arm pivoted to the lift frame, means for causing pivotal movement of said crank arm, a connecting rod pivotally connected at one end to said crank arm and at its other end to said linkage, the pivot which is connected to said crank arm being movable to an over-center position with respect to the pivot for the crank arm and with respect to the pivotal connection with the linkage when the platform is in an upright position to mechanically lock the platform in said tailgate-closing position.