GB2174972A

GB2174972A - Vehicle tail-lift safety lock

Info

Publication number: GB2174972A
Application number: GB08610603A
Authority: GB
Inventors: Peter Ross; Charles Jackson Badasha
Original assignee: Ross and Bonnyman Engineering Ltd
Current assignee: Ross and Bonnyman Engineering Ltd
Priority date: 1985-05-15
Filing date: 1986-04-30
Publication date: 1986-11-19
Also published as: GB8610603D0; GB2174972B

Abstract

The present invention provides a vehicle tail-lift 1 provided with a safety lock 10 for retaining the load platform 4 of the tail-lift 1 in a vertical stowed position on the support columns 2 of the lift 1 in the event of failure of the lifting mechanism of the tail-lift. The safety lock 10 comprises an engagement member 8 on one side of the load platform 4 formed and arranged for latching engagement with a latching means 13 provided at the respective support column 2. The latching means 13 has a control means 20 formed and arranged for releasing the engagement member 8 from latching engagement when required. A stop member 21 is provided at the other support column 2 generally opposite the latching means 13 and laterally adjacent an opposed side edge portion 22 of the load platform 4, for abutment with said side edge portion 22 upon failure of the lifting mechanism and tilting of the load platform 4 about the engagement member 8. <IMAGE>

Description

SPECIFICATION Safety lock The present invention relates to safety locks and in particular to a vehicle tail-lift provided with a safety lock.

Increasing numbers of goods vehicles are provided with tail-lifts for use in loading and unloading of goods. Many such tail-lifts are based on a design having a load platform movable up and down on support columns mounted at either side of the rear access opening. With this design the load platform is held in a stowed position during transit in which it is partly raised by the lifting mechanism of the tail-lift, the platform being swung up against the rear door of the vehicle.

With such an arrangement there is a risk of the load platform falling in the event of failure of the lifting mechanism during transit. This can result in damage to the tail-lift and/or the vehicle and possibly also danger to other road users.

It is an object of the present invention to avoid or minimize one or more of the above disadvantages.

The present invention provides a vehicle tail-lift provided with a safety lock for retaining the load platform of said tail-lift substantially in a stowed position thereof on the support columns thereof, in the event of failure of the lifting mechanism of said tail-lift, said safety lock comprising an engagement member on one side of the load platform formed and arranged for latching engagement with a latching means provided at the respective support column at said side of the load platform, said latching means having a control means formed and arranged for releasing said engagement member from said latching engagement when required, and a stop member provided at the other support column generally opposite said latching means and laterally adjacent an opposed side edge portion of the load ramp, for abutment with said side edge portion upon failure of the lifting mechanism and tilting of the load ramp about said engagement member.

Thus with a tail-lift of the present invention falling of the load platform from its full stowed or transit position, upon failure of the lift mechanism is substantially prevented in a simple and economic manner which at the same time permits ready release of the safety lock by a single operator.

Further preferred features and advantages of the invention will appear from the following detailed description given by way of example of a preferred embodiment illustrated with reference to accompanying drawings in which: Figure 1 is a partial schematic rear view of a vehicle tail-lift; Figure 2 is a detail side view of one side of the tail-lift of Figure 1; Figure 3 is a schematic plan view (partially sectioned) of the tail-lift of Figure 1; and Figure 4 is a detail perspective view of the safety lock of the tail-lift of Figure 1.

Figure 1 shows a vehicle tail-lift 1 comprising a pair of support columns 2 either side of an access opening 3 and mounting a load platform 4 provided with runners 5 which move the load platform 4 up and down the columns 2 with the aid of a lift ing mechanism (not shown). At one side 6 adjacent a free outer corner 7 of the load platform, is mounted a laterally projecting pin 8 on a laterally outer face 9 of the corresponding support column 2, at an intermediate position, is mounted a latch ing mechanism 10.

As shown in Figure 4, the latching mechanism 10 comprises a base plate 11 having a raised boss 12 and adjacent thereto a pivotally mounted latch member 13. At its lower end 14 the latch member 13 has a cam surface 15 which is engaged by the - pin 8 on the load platform as this is raised to deflect the latch member 13 allowing the pin 15 to enter a pin-receiving recess 16 in the boss 12 in which it is retained by the latch member 13 in the locking position of the latter which is maintained by the spring force of a return spring 17 acting on the other side 18 of the latch member lower end 14.At the other side of the pivotal mounting 19 of the latch member 13 the latter is provided with a control lever 20 which can be manually displaced by a single operator to pivot the latching member 13 to its release position allowing the pin 15 to be disengaged and the load platform 4 lowered.

At the other column 2 generally directly opposite the latching mechanism 10, there is mounted a stop member 21 adjacent the opposed edge 22 of the load platform 4 so that the latter contacts said stop member 21 upon any tendency of the load platform to tilt about the latching mechanism - as for example in case of failure of the lifting mecha nism, so that the load platform is held up in its stowed or transit position by the latching mecha nism and stop member. It will be appreciated that in this way the load platform can be securely sup ported in the stowed position by means of a relatively economic arrangement which does not require complex and expensive linking between the two sides of the platform and which at the same time does not interfere with normal operation and can be easily released by a single operator.

1. A vehicle tail-lift provided with a safety lock for retaining the load platform of said tail-lift sub stantially in a stowed position thereof on the sup port columns thereof, in the event of failure of the lifting mechanism of said tail-lift, said safety lock comprising an engagement member on one side of the load platform formed and arranged for latching engagement with a latching means provided at the respective support column at said side of the load platform, said latching means having a control means formed and arranged for releasing said en gagement member from said latching engagement when required, and a stop member provided at the other support column generally opposite said latching means and laterally adjacent an opposed

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Safety lock The present invention relates to safety locks and in particular to a vehicle tail-lift provided with a safety lock. Increasing numbers of goods vehicles are provided with tail-lifts for use in loading and unloading of goods. Many such tail-lifts are based on a design having a load platform movable up and down on support columns mounted at either side of the rear access opening. With this design the load platform is held in a stowed position during transit in which it is partly raised by the lifting mechanism of the tail-lift, the platform being swung up against the rear door of the vehicle. With such an arrangement there is a risk of the load platform falling in the event of failure of the lifting mechanism during transit. This can result in damage to the tail-lift and/or the vehicle and possibly also danger to other road users. It is an object of the present invention to avoid or minimize one or more of the above disadvantages. The present invention provides a vehicle tail-lift provided with a safety lock for retaining the load platform of said tail-lift substantially in a stowed position thereof on the support columns thereof, in the event of failure of the lifting mechanism of said tail-lift, said safety lock comprising an engagement member on one side of the load platform formed and arranged for latching engagement with a latching means provided at the respective support column at said side of the load platform, said latching means having a control means formed and arranged for releasing said engagement member from said latching engagement when required, and a stop member provided at the other support column generally opposite said latching means and laterally adjacent an opposed side edge portion of the load ramp, for abutment with said side edge portion upon failure of the lifting mechanism and tilting of the load ramp about said engagement member. Thus with a tail-lift of the present invention falling of the load platform from its full stowed or transit position, upon failure of the lift mechanism is substantially prevented in a simple and economic manner which at the same time permits ready release of the safety lock by a single operator. Further preferred features and advantages of the invention will appear from the following detailed description given by way of example of a preferred embodiment illustrated with reference to accompanying drawings in which: Figure 1 is a partial schematic rear view of a vehicle tail-lift; Figure 2 is a detail side view of one side of the tail-lift of Figure 1; Figure 3 is a schematic plan view (partially sectioned) of the tail-lift of Figure 1; and Figure 4 is a detail perspective view of the safety lock of the tail-lift of Figure 1. Figure 1 shows a vehicle tail-lift 1 comprising a pair of support columns 2 either side of an access opening 3 and mounting a load platform 4 provided with runners 5 which move the load platform 4 up and down the columns 2 with the aid of a lift ing mechanism (not shown). At one side 6 adjacent a free outer corner 7 of the load platform, is mounted a laterally projecting pin 8 on a laterally outer face 9 of the corresponding support column 2, at an intermediate position, is mounted a latch ing mechanism 10. As shown in Figure 4, the latching mechanism 10 comprises a base plate 11 having a raised boss 12 and adjacent thereto a pivotally mounted latch member 13. At its lower end 14 the latch member 13 has a cam surface 15 which is engaged by the - pin 8 on the load platform as this is raised to deflect the latch member 13 allowing the pin 15 to enter a pin-receiving recess 16 in the boss 12 in which it is retained by the latch member 13 in the locking position of the latter which is maintained by the spring force of a return spring 17 acting on the other side 18 of the latch member lower end 14.At the other side of the pivotal mounting 19 of the latch member 13 the latter is provided with a control lever 20 which can be manually displaced by a single operator to pivot the latching member 13 to its release position allowing the pin 15 to be disengaged and the load platform 4 lowered. At the other column 2 generally directly opposite the latching mechanism 10, there is mounted a stop member 21 adjacent the opposed edge 22 of the load platform 4 so that the latter contacts said stop member 21 upon any tendency of the load platform to tilt about the latching mechanism - as for example in case of failure of the lifting mecha nism, so that the load platform is held up in its stowed or transit position by the latching mecha nism and stop member. It will be appreciated that in this way the load platform can be securely sup ported in the stowed position by means of a relatively economic arrangement which does not require complex and expensive linking between the two sides of the platform and which at the same time does not interfere with normal operation and can be easily released by a single operator. CLAIMS

1. A vehicle tail-lift provided with a safety lock for retaining the load platform of said tail-lift sub stantially in a stowed position thereof on the sup port columns thereof, in the event of failure of the lifting mechanism of said tail-lift, said safety lock comprising an engagement member on one side of the load platform formed and arranged for latching engagement with a latching means provided at the respective support column at said side of the load platform, said latching means having a control means formed and arranged for releasing said en gagement member from said latching engagement when required, and a stop member provided at the other support column generally opposite said latching means and laterally adjacent an opposed side edge portion of the load platform, for abutment with said side edge portion upon failure of the lifting mechanism and tilting of the load platform about said engagement member.

2. A tail-lift as claimed in claim 1 wherein the engagement member is in the form of a laterally extending projection.

3. A tail-lift as claimed in claim 2 wherein the latching means is in the form of a pivotally mounted member having a cam surface formed and arranged so as to be engagable by the engagement member as the load platform moves upwardly into its stowed position, and temporarily displacable by said engagement member from its locking position into an open position for permitting entry of the engagement member into a locked position thereof behind a retaining face of the latching means member.

4. A tail-lift as claimed in claim 3 wherein said latching means is provided with a resilient biasing means formed and arranged for biasing said latching means into its locking position.

5. A tail-lift as claimed in claim 3 or claim 4 wherein the latching member has a control lever extending outwardly therefrom for pivoting of the latching member about its pivotal mounting.

6. A tail-lift provided with a safety lock substantially as described hereinbefore with particular reference to the accompanying drawings.