Safety lock for tailgate lift

A power operated tailgate for use in association with a truck body comprising:

• (a) a load supporting platform,
• (b) first and second longitudinally elongated slide members mounted one at either side of said platform and extending upwardly therefrom,
• (c) a frame including first and second guide members mountable on said body and adapted to guide the first and second slide members respectively as they are raised and lowered in use,
• (d) a hoist mechanism for raising and lowering said platform comprising;
• (i) a winding mechanism mounted on said frame,
• (ii) first and second power transmission chains each having one end in driving engagement with the winding mechanism and the other ends thereof being connected to the first and second slide members respectively whereby the weight of the platform and slide members is applied as a tensioning load to said chains,
• (iii) said winding mechanism being operable to wind-in and pay-out said chains to raise or lower said platform,
• (e) first and second detector levers each having a chain slipway extending therethrough, said detector levers being mounted on said frame for movement between a first position and a second position, said first and second chains extending through the slipways of said first and second levers respectively and, when subjected to said normal tensioning loads, supporting said detector levers in said first position, said first and second detector levers being adapted to move to said second position in response to a break in said first or second chains respectively, and
• (f) first and second latch arms pivotally mounted on said frame adjacent first and second slide members respectively, said first and second latch arms each being movable between a latching position engaging and locking its associated slide member to prevent lowering thereof and a release out of lock engagement with its associated slide,
• (g) latch actuating means for moving said latch arms between said latching position and said release position, said latch actuating means
• comprising;
• (i) means normally urging said latch arms to said latching position,
• (ii) a flexible connector connecting said first and second latch means, said flexible connector engaging said first and second tension detector levers so as to be retained by said first and second tension detector levers in a position retaining said first and second latch arms in their release position when a normal tensioning load is detected in said first and second power transmission members respectively, said flexible connector being slackened when either one of said first or second tension detector levers moves away from its raised position so as to cause movement of said first and second latching arms to their latching position when said detector levers detect the absence of a normal tensioning load in said first or second power transmission members respectively.