GB2233938A

GB2233938A - Tail gate latching mechanism

Info

Publication number: GB2233938A
Application number: GB8916704A
Authority: GB
Inventors: Glyndwr Shaw
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-07-21
Filing date: 1989-07-21
Publication date: 1991-01-23
Anticipated expiration: 2009-07-21
Also published as: GB8916704D0; GB2233938B

Abstract

A remotely operated latching mechanism (22) for the tail-gate (18) of the tipping body (12) of a goods vehicle (10) comprises a pneumatically operated ram (24) which rotates a locking bar (34) through a linkage comprising a sliding bar (28) and a coupling (30). The actuating means for the ram (24) is disposed within the vehicle cab so that the driver does not have to leave the cab to open the tail-gate. The locking bar (34) has five latches (36) which are engageable with or disengageable from the vehicle tail-gate (18) to either lock the tail-gate in a closed position or release the tail-gate enabling the tail-gate to open under the force of gravity. A stub extension (34a) of the locking bar (34) permits manual operation of the latch should the mechanism 22 fail. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO LATCHING MECHANISMS This invention relates to latching mechanisms. In particular the invention relates to a latching mechanism for use in conjunction with the tail-gate of the tipping body of a goods vehicle.

Goods vehicles are available for the transport and disposal of loose materials such as hard core, top soil, builders rubble and industrial and domestic refuse. Such vehicles usually have a body which is hinged at one end so that the body can be tipped, for example by use of an hydraulic ram enabling the loose material in the body to be discharged from the vehicle using the force of gravity.

The bodies of such vehicles usually have a tail-gate which is hinged along its top edge, and the tail-gate has a latching mechanism to retain the tail-gate in the closed position or allowing the tail-gate to be released so that the gate swings open as the vehicle body is tipped.

The mechanism can either be manually operated or the tail-gate can be formed in two sections which can be opened and closed by the use of one or more hydraulic or pneumatic rams connected to the two portions of the tail-gate by a scissor type linkage. In the manual case where the tail-gate has to be operated the driver of the vehicle has to leave his cab in order to open or close the tail-gate. The underfoot conditions particularly in inclement weather at sites where the material being transported is to be discharged are usually such that the cab of the vehicle quickly becomes soiled.

Also in the case of the known power operated tail-gate the operating mechanism is susceptible to damage either by the ingress of foreign matter or as a result of the practice of using another vehicle to shunt the vehicle from a site if the vehicle becomes stuck on site.

In such circumstances it is not unusual for the operating mechanism to become unservicable and there is no provision for a manual override allowing the tail-gate to be released and operated by hand.

The present invention seeks to provide a latching mechanism for the tail-gate of the tipping body of a commercial goods vehicle in which the latching mechanism can be operated from the vehicle cab and which allows for the manual operation of the tail-gate should the actuating mechanism for the tail-gate fail for any reason.

Accordingly the present invention provides a tail-gate latching mechanism comprising a rotatable bar mounted for rotation on the tipping body of a commercial goods vehicle, at least one latch attached to the rotatable bar, the or each latch being engagable with and disengagable from the tail-gate of the tipping body so as to retain the tail-gate in a closed position or to release the tail-gate allowing it to open respectively, actuating means connected to the rotatable bar and operating means for the actuating means located in the cab of the commercial vehicle.

Preferably more than one latch is provided, for example, five latches can be attached to the rod.

The actuating means can comprise a fluid operated ram and the operating means can comprise a valve connected to the fluid power supply of the vehicle enabling the fluid operated ram to operate.

The fluid can be hydraulic or pneumatic, though for convenience, the fluid is compressed air supplied from the compressed air source for the vehicle brakes.

The hydraulic or pneumatic ram can be connected to the rotatable bar by means of a sliding coupling attached at one end to the ram of the operating means and at the other end to one end of a double ended coupling, the other end of the double ended coupling being attached to an arm attached to the rotating bar.

The sliding bar coupling can be located in a slideway attached to the undersurface of the tipping body, and can be encased in a steel cover to prevent damage to the mechanism.

The rotatable locking bar can have one end turned through a right angle enabling an extension arm in the form of, for example a pipe to be located over the said one end to enable the locking bar to be rotated manually independently of the hydraulic or pneumatic ram.

The locking bar can be provided with visual indicating means enabling the position of the locking bar to be viewed from the cab of the goods vehicle.

The visual indicating means can comprise a disc attached to the locking bar arranged so that the disc is seen face on when the tail-gate is locked and edge on when the gate is open or vice-versa.

The present invention will now be more particularly described with reference to the accompanying drawings in which Fig. 1 is a schematic view of a goods vehicle having one form of latching mechanism according to the present invention, Fig 2 is an exploded perspective view of the latching mechanism shown in Fig. 1, Fig. 3 is a perspective view of the latching mechanism shown in Fig. 2 in a first position, Fig. 4 is a side view of the latching mechanism shown in Fig. 3, Fig. 5 is a perspective view of the latching mechanism shown in Fig. 2 in a second position, and Fig. 6 is a side view of the latching mechanism shown in Fig. 5.

Referring to the drawings there is shown a commercial goods vehicle 10 with having a tipping body 12 which is hinged about an axis of rotation 14. The vehicle has an hydraulic ram 16 enabling the body 12 to be moved to a tipping position.

The body 12 has a tail-gate 18 which is hinged about its top edge 20 and a latching mechanism 22 is attached to the undersurface of the tipping body with a control mechanism located in the cab of the vehicle.

Referring more particularly to Fig. 2 the latching mechanism 22 comprises a ram 24 which can be either hydraulically or pneumatically powered. The ram 24 has a rod 26 attached to a piston (not shown) located within the cylinder of the ram and the free end of the rod 26 is attached to one end of a sliding bar coupling 28. The other end of the sliding bar coupling is attached to one end of a double ended coupling 30. The other end of the double ended coupling 30 is attached to an arm 32 which is welded to a rotatable locking bar 34.

The locking bar 34 is mounted for rotation on the tipping body 12 and has five latches 36 only one of which is shown engagable with and disengagable from the lower edge of the tail-gate 18.

The double ended coupling 30 is adjustable in length so that for a given travel of the rod 26 of the ram the latch 36 will either fully engage or disengage the tail-gate of the tipping body. The sliding bar coupling 28 is located in a slideway 38 attached to the undersurface of the tipping body. As shown in Figs. 4 and 6 only the sliding bar coupling and double ended coupling extend through an opening 40 in a finishing plate 42 of the tipper body.

As shown in Figs. 4 and 6 only, the power supply for the ram 24 is taken from an existing pneumatic supply line 44 on the vehicle to either one side or the other side of the piston of the ram through pipe lines 46 and 48 via a valve 50 located in the vehicle cab. The vehicle has a manually operated control 52 to enable fluid power to be supplied through either of the power lines 46 and 48 to either open or close the latching mechanism respectively.

In use the tipper body is loaded with loose material for example builders rubble or hard core with the tipper body in a horizontal position and with the tail-gate secured in the closed position by the latching mechanism 22 being in the position illustrated in Figs. 3 and 4. The loose material is then transported to a site where the material is to be dumped. Such a site will certainly have much loose material on the surface and in wet conditions the site will quite likely be very muddy and loose in nature. The vehicle is positioned so as to discharge the transported material at approximately the correct location. The latching mechanism 22 is operated by the driver who remains seated in the cab, by movement of the lever 52 which supplies air power from the line 44 to the line 46 causing the rod 26 to move in the direction of arrow A. The sliding bar coupling 28 moves along the slideway 38 and the double ended coupling 30 draws the arm 32 downwards rotating the locking bar 34 and disengaging the latches 36 from the tail-gate of the tipping body.

The ram on the tipping body is then operated once again from within the driver's cab, causing the body to rotate about the axis 14 and the material within the tipping body to be discharged under the force of gravity. If necessary the discharge of material can be assisted by repeatedly driving the vehicle backwards and forwards with the tipper body raised.

Once all the material has been discharged the tipper body is lowered on the ram 16. When the tipper body is level on the vehicle the valve 50 is operated by the arm 52 to cause power to be provided from line 44 through line 48 to move the rod 26 in the direction of arrow B causing the latch 36 to engage the tail-gate so as to maintain the tail-gate in a closed position.

It will be appreciated that when the latch is in the tail-gate open position the arm 32 which is appropriately sized, will close off the opening 42 in the finishing plate 40 thereby preventing substantial ingress of foreign matter into the operating mechanism of the locking bar and latch 34 and 36 respectively.

The locking bar 34 can have an end turned through an angle for example a right angle so as to provide a stub 34A to enable an extension lever 54 to be placed over the stub 34A. Such an arrangement allows the latching mechanism to be operated manually should the mechanism 22 fail for any reason.

If the mechanism 22 should fail in the open position (Fig. 6) it will be necessary to disconnect the coupling 30 to enable the locking bar 34 to be turned to engage the latches 36 with the tail-gate 18. The coupling 30 does not have to be disconnected in the mechanism fails in the closed position (Fig. 4) to enable the mechanism to be operated to release the latches. Such an arrangement ensures that even if the mechanism 22 fails, the vehicle can continue to be used, until it is convenient to repair the failed mechanism.

Also the mechanism 22 is fail-safe in that, if the mechanism fails, for example as a result of loss of pneumatic power, the latches 36 will remain in the closed position, retaining the tail-gate 18 in the closed position.

Referring to Fig. 5 a visual indicator in the form of a disc 56 is attached to the locking bar 34. In the example the disc is positioned so that it can be seen face on when the latch 36 is disengaged and edge on when the latch is engaged, by the vehicle either directly or throught the vehicle rearview mirror.

The latching mechanism has been described in the above embodiment as having five latches on the locking bar, though depending upon the application, fewer or more latches may be suitable. For example, only one latch may be necessary to retain the tail-gate.

Also, the embodiment discloses the use of compressed air, taken conveniently from the compressed air supply for the vehicle brakes, to operate the latching mechanism. If the vehicle has an hydraulic power supply, this source of fluid power can also be used to operate the latching mechanism.

A latching mechanism for the tail-gate of the tipping body of a goods vehicle according to the present invention provides a simple and reliable means of releasing and locking the tail-gate from the vehicle cab so as to avoid the vehicle driver from having to leave the cab. Thus time will be saved and the amount of foreign matter transported into the cab underfoot will be reduced. Also the latching mechanism according to the present invention provides that there is a manual override and also provides a visual indication of the position of the latching mechanism.

Claims

1. A tail-gate latching mechanism comprising a rotatable bar mounted for rotation on the tipping body of a commercial goods vehicle, at least one latch attached to the rotatable bar, the or each latch being engageable with and disengageable from the tail-gate of the tipping body so as to retain the tail-gate in a closed position or to release the tail-gate allowing it to open respectively, actuating means connected to the rotatable bar and operating means for the actuating means located in the cab of the commercial vehicle.

2. A latching mechanism as claimed in claim 1 in which the actuating means comprises a fluid operated ram and the operating means comprises a valve connected to the fluid power supply of the vehicle.

3. A latching mechanism as claimed in claim 2 in which the fluid power supply is a supply of compressed air available on the vehicle to operate the vehicle brakes.

4. A latching mechanism as claimed in claim 3 in which the pneumatically operated ram is connected to the rotatable bar by means of a sliding bar coupling attached at one end to the ram and at the other to one end of a double ended coupling, the other end of the double ended coupling being attached to an arm attached to the rotating bar.

5. A latching mechanism as claimed in claim 4 in which the sliding bar coupling is located in a slideway attached to the undersurface of the tipping body of the vehicle.

6. A latching mechanism as claimed in claim 5 in which the sliding bar coupling and slideway are encased in a cover.

7. A latching mechanism as claimed in any one of the preceeding claims in which the rotatable locking bar has one end turned through an angle so as to enable an extension arm to be attached to the said one end to rotate the locking bar manually.

8. A latching mechanism as claimed in any one of the preceeding claims in which the locking bar is provided with visual indicating means enabling the position of the locking bar to be viewed from the cab of the vehicle.

9. A latching mechanism as claimed in claim 8 in which the visual indicating means comprises a disc attached to the locking bar arranged so that the disc is seen face on when the tail-gate is locked and edge on when the gate is open.

10. A latching mechanism as claimed in claim 8 in which the visual indicating means comprises a disc attached to the locking bar arranged so that the disc is seen edge on when the tail-gate is locked and face on when the tail-gate is open.

11. A latching mechanism as claimed in any one of the preceeding claims in which the rotatable locking bar is provided with five latches.

12. A latching mechanism constructed and arranged for use and operation substantially as herein described and with reference to the accompanying drawings.