GB1569095A

GB1569095A - Lock for anchoring a vehicle cab of the tippable type

Info

Publication number: GB1569095A
Application number: GB1415678A
Authority: GB
Original assignee: Fiat Veicoli Industriali SpA
Current assignee: Fiat Veicoli Industriali SpA
Priority date: 1977-06-15
Filing date: 1978-04-11
Publication date: 1980-06-11
Also published as: FR2394657A1; FR2394657B1; DE2821364A1; IT1083523B

Description

(54) LOCK FOR ANCHORING A VEHICLE CAB OF THE TlPPABLE TYPE (71) We, FIAT VEICOLI INDUSTRIALI S.p.A., an Italian joint stock company, of Via Puglia 35, Turin, Italy, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a lock for anchoring a vehicle cab of the tippable type, applicable particularly but not exclusively to trucks.

A lock for a tippable cab cooperates with a catch which may in theory be fixed to the vehicle chassis or to the tipping cab itself.

Normally, however, the catch is fixed to the chassis of the vehicle and the lock is carried on the cab. A known such type of lock comprises a movable anchoring element which engages the catch so as to anchor the cab, a movable locking element urged by a spring towards a locking position in which it engages the anchoring element to lock the latter in its engaged position, the locking element being connectible to an operating device for applying to the locking element a release force to move it away from its locking position against the action of the spring, and a stop element which is movable into a stop position in which it engages the locking element after its release in order to keep the locking element away from its locking position so that the release force can be removed from the locking element without the latter returning to its locking position. This enables the operator to work the lock operating device by hand in order to release the lock and then move to another place to effect tipping of the said cab. Normally the lock operating device is inside the cab, for safety reasons, so as to prevent its inadvertent ration by unknown persons, while out the the cab there is a hand-operable hydrau- lic system, for tipping the cab; the truck driver operates the lock, then alights from the cabin to operate the hydraulic system.

The object of the present invention is to provide a lock of the aforesaid kind, hand controlled and of small dimensions, which can be operated smoothly and easily with very little friction.

The present invention accordingly provides a lock of the type referred to characterised in that the anchoring element and the locking element and the stop element are rotatably mounted, the stop element being constrained by a spring towards its stop postiion and the anchoring element being arranged so that, in the course of tipping of the cab, the catch moves the anchoring element which in turn disengages the stop element from the locking element and allows the latter to move to a position in which it can be returned to its locking position upon return of the catch into engagement with the anchoring element, thereby avoiding a separate operation for moving the stop element into the stop position.

The components of the lock of the present invention perform only rotary movements relative to each other, with little friction, thus permitting easy and gentle purely mechanical operation of the lock under manual control. The use of three rotatable elements allows a compact lock design requiring less space, contains less material such as steel in its construction, and weighs less than previously known locks of the type referred to. The lock can be even more compact if, as is preferred, the anchoring, locking and stop elements are constrained by hairpin springs. Since the locking element is rotatable the operating element can be connected to any suitable part of the locking element and the direction of the release force can be more freely chosen. The use of three rotatable elemenls facilitates the design of the lock so that any contact is avoided between the catch and the stop element.

The invention will be further described, by way of non-limiting example, with reference to the accompanying drawings, in which: Figure 1 shows on a reduced scale a lock according to one embodiment of the inven tion with an operating device, a portion of a chassis of a vehicle, and a portion of the bottom of tippable cab; Figure 2 shows, on a larger scale than that of Figure 1, a vertical cross-section of the lock taken along the line II-II of Figure 6; Figures 3 and 4 are cross-sections corresponding to the section shown in Figure 2, in which the lock appears in two different positions; Figure 5 is a cross-section taken along the line V-V of Figure 2; Figure 6 is a cross-section taken along the line VI-VI of Figure 3, and Figure 7 is a cross-section taken along the line VII-VII of Figure 3.

As shown in Figure 1, the lock of the invention, designated 1, is fixed to the bottom 2 of a cab of the tippable type of a heavy truck by means of mounting flanges 3 on the lock 1. The cab tips about an axis parallel to the plane of Figure 1 and in front of this plane. The lock engages a catch in the form of a pin 4 secured to a longitudinal chassis member of the truck by means of a bracket and a shock absorbing mounting (not shown). An identical lock is located on the other side of the cab, and a safety latch (not shown) may be provided to prevent accidental release of the locks and tipping of the cab. The two locks 1 are both connected to a manual operating element 5 by means of flexible sheathed cables 6. The operating element 5 would normally be situated behind the driver's seat inside the cab.

Referring to Figures 2 to 7, the lock 1 comprises a box-type casing 7 traversed by two pins 8, 9 and by three rivets 10, 11, 12. Three rotatable elements are pivoted upon the pins 8, 9, these rotatable elements comprising an anchor lever 13, a locking lever 14 and a stop lever 15. The anchor lever 13 and the stop lever 15 are pivoted around the pin 8, while the locking lever 14 is pivoted around the pin 9. As can be seen from Figure 4, the pivot axes of all three levers 13, 14 and 15 are disposed on one side of the path 16, shown by a broken line, of the catch pin 4 relative to the lock 1 in the course of latching and unlatching movement.

As shown in Figure 5, the levers 13, 14 and 15 are in the form of plates and the levers 13 and 14 are in the same plane.

The anchor 13 is constrained by a hairpin spring 17 one end of which bears on the rivet 10 the other end of which (Figure 5) bears on a pin 18 fixed to the anchor lever 13 in such a manner that the spring 17 urges the anchor lever 13 towards the release position illustrated in Figure 4. The locking lever 14 is constrained by a pairpin spring 19 towards a locking position shown in Figure 2, in which the locking lever 14 engages the anchor lever 13 so as to lock the latter. The stop lever 15 is constrained by a hairpin spring 20 one end of which bears upon the pin 18 and the other end of which bears upon a stud 21 fixed to the stop lever 15 so that the latter is thrust towards a stop position, illustrated in Figure 3, in which it engages the locking lever 14 in order to hold it away in its locking position. It will be seen that the coils of the hairpin springs 17, 19 and 20 surround the pivot axes of the respective levers 13, 14, 15.

The locking lever 14 has a connector arm 22 which is connected to one end of the flexible cable 6 (Figure 1), a projecting bracket 23 on the cab bottom 2 serving as an anchorage for the sheath of the flexible cable.

A screw-threaded hole 24 is bored in one edge of the lock casing 7 (Figure 5) to receive a normally open switch (not shown) which is arranged to be closed when the locking lever 14 is moved away from its locking position, to cause a warning light on the dashboard of the truck to be lit when the lock 1 is not in the safe condition.

Figure 2 shows the lock 1 in the safe condition with the pin 4 engaged by the anchor lever 13. In this condition the locking lever 14 has a locking heel 25 which engages a radially extending locking surface 26 on the anchor lever 13, thus locking the anchor lever 13. The locking surface 26 in this condition is approximately tangential to a circle having its centre on the axis of the pivot pin 9. The stop lever 15 bears against the locking lever 14 by means of a small stop roller 27 freely rotatable upon the stud 21 (Figure 6).

When a releasing force is applied by means of the operating element 5 and cable 6 to the arm 22 of the locking lever 14, as indicated by the arrow F in Figure 2, the locking lever 14 is moved away from the locking position against the action of its biassing spring 19, and the locking lever 14 assumes the released position shown in Figure 3. The stop roller 27 on the stop lever 15 follows the surface of the locking lever 14 and moves into engagement with a stop surface 28 of the locking lever 14.

The stop surface 28 is substantially tangential to a circle the centre of which is on the axis of the pivot pin 8, and when the roller 27 engages the stop surface 28 the locking lever 14 is effectively locked in its released position. The releasing force F can then be removed and the operating element 5 released without the locking lever 14 returning to the position in which it locks the -anchor lever 13.

The truck driver can now alight from the cab and operate the hydraulic system to tip the cab. In the course of such tipping the pin 4 moves along the path 16 and displaces the anchor lever 13 into the released position shown in Figure 4; during this movement a non-circumferential bearing surface 29 on the anchor lever 13 engages an abutment 30 projecting from the stop lever 15, thereby moving the stop lever 15 into the position shown in Figure 4 and releasing the stop roller 27 from engagement with the stop surface 28. This in turn releases the locking lever 14 and allows its movement under the influence of its biassing spring 19 into a position in which the locking lever 14 can lock the anchor lever 13 upon the return of the pin 4 into locking engagement with the anchor lever 13. In this position the abutment 30 is held by the bearing surface 29 against the rivet 12, and the heel 25 of the locking lever 14 bears horizontally against a surface 31 to the anchor lever 13 (Figure 4).

When the cab is rotated back to its nor mal driving position the pin 4 moves the anchor lever 13 into the position shown in Figures 2 and 3, whereupon the locking lever 14, under the influence of the spring 19, returns to the locking position shown in Figure 2 with its heel 25 engaging the locking surface, and the stop lever 15, under the influence of the spring 20, returns to the safety position illustrated in Figure 2.

The constructional simplicity and the reliability of the lock will be apparent from what has been described, the lock being compact, and consisting of a few easily assembled stamped components so that the entire lock is both advantageous and also economical.

Figure 1 shows two locks 1 laterally positioned below the cab, the positioning being suitable for a short cab. Alternatively a single lock 1 can be assembled longitudinally below the centre of the cab, for cabs of considerable length.

Tt will be understood that without changing the principle of the invention construction details of the lock may be widely varied whilst still remaining within the scope of the invention.

WHAT WE CLAIM IS:- 1. A lock for engaging a catch for anchoring a tippable cab of a vehicle, comprising a rotatable anchoring element which engages the said catch for anchoring the cab; a rotatable locking element urged by a spring towards a locking position in which it engages the anchoring element to lock the latter in its engaged position, the locking element being connectible to an operating device for applying to the locking element a release force to move it away from its locking position against the action of the spring, and a rotatable stop element urged by a spring into a stop position in which it engages the locking element after its release in order to keep the locking element away from its locking position so that the locking element does not return to its locking position upon removal of the release force, the anchoring element being arranged so that, in the course of tipping of the cab, the catch moves the anchoring element which in turn disengages the stop element from the locking element and allows the latter to move to a position in which it can be returned to its locking position upon return of the catch into engagement with the anchoring element, thereby avoiding a separate operation for moving the stop element into the stop position.

2. A lock according to Claim 1, in which the axes of rotation of the anchoring element, the locking element and the stop element are all situated on the same side of the path of movement of the catch in the course of engagement of the latter with the anchoring element.

3. A lock according to Claim 2, in which the anchoring element, the locking element and the stop element are all constrained by respective hairpin springs having coils which surround the pivot pins of the stop element and the locking element respectively.

4. A lock according to any of the preceding claims, in which the anchoring element and the stop element have a common pivot axis.

5. A lock according to Claim 4, in which the anchoring element has a locking surface, substantially radial with respect to the pivot axis of the anchoring element, extending approximately tangentially to a circle centered upon the pivot axis of the locking element when the catch is engaged by the anchoring element, and also has a non-circumferential bearing surface; the locking element has a heel portion for engaging the locking surface of the anchoring element to lock the latter and a stop surface which extends approximately tangentially to a circle centered on the pivot axis of the stop element when the catch is engaged by the anchoring element, and the stop element has a stop portion engageable with said stop surface for keening the locking element away from its locking position, and an abutment portion for engaging the bearing surface of the anchoring element so as to disengage the stop element from the locking element during movement of the anchoring element by the catch in the course of tipping of the cab.

6. A lock according to Claim 5, in which the anchoring element and the lock

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the cab. In the course of such tipping the pin 4 moves along the path 16 and displaces the anchor lever 13 into the released position shown in Figure 4; during this movement a non-circumferential bearing surface 29 on the anchor lever 13 engages an abutment 30 projecting from the stop lever 15, thereby moving the stop lever 15 into the position shown in Figure 4 and releasing the stop roller 27 from engagement with the stop surface 28. This in turn releases the locking lever 14 and allows its movement under the influence of its biassing spring 19 into a position in which the locking lever 14 can lock the anchor lever 13 upon the return of the pin 4 into locking engagement with the anchor lever 13. In this position the abutment 30 is held by the bearing surface 29 against the rivet 12, and the heel 25 of the locking lever 14 bears horizontally against a surface 31 to the anchor lever 13 (Figure 4). When the cab is rotated back to its nor mal driving position the pin 4 moves the anchor lever 13 into the position shown in Figures 2 and 3, whereupon the locking lever 14, under the influence of the spring 19, returns to the locking position shown in Figure 2 with its heel 25 engaging the locking surface, and the stop lever 15, under the influence of the spring 20, returns to the safety position illustrated in Figure 2. The constructional simplicity and the reliability of the lock will be apparent from what has been described, the lock being compact, and consisting of a few easily assembled stamped components so that the entire lock is both advantageous and also economical. Figure 1 shows two locks 1 laterally positioned below the cab, the positioning being suitable for a short cab. Alternatively a single lock 1 can be assembled longitudinally below the centre of the cab, for cabs of considerable length. Tt will be understood that without changing the principle of the invention construction details of the lock may be widely varied whilst still remaining within the scope of the invention. WHAT WE CLAIM IS:-

1. A lock for engaging a catch for anchoring a tippable cab of a vehicle, comprising a rotatable anchoring element which engages the said catch for anchoring the cab; a rotatable locking element urged by a spring towards a locking position in which it engages the anchoring element to lock the latter in its engaged position, the locking element being connectible to an operating device for applying to the locking element a release force to move it away from its locking position against the action of the spring, and a rotatable stop element urged by a spring into a stop position in which it engages the locking element after its release in order to keep the locking element away from its locking position so that the locking element does not return to its locking position upon removal of the release force, the anchoring element being arranged so that, in the course of tipping of the cab, the catch moves the anchoring element which in turn disengages the stop element from the locking element and allows the latter to move to a position in which it can be returned to its locking position upon return of the catch into engagement with the anchoring element, thereby avoiding a separate operation for moving the stop element into the stop position.

6. A lock according to Claim 5, in which the anchoring element and the lock

ing element are in the form of plates disposed in a common plane.

7. A lock according to Claim 6, in which the stop portion and the abutment portion of the stop element comprise projections disposed at least partially in the common plane of the anchoring element and of the locking element.

8. A lock according to any of the preceding claims, in which the spring constraining the stop element reacts against the anchoring element, thus urging the anchoring element and the stop element angularly relatively to each other.

9. A lock for engaging a catch for anchoring a tippable cab of a vehicle, substantially as herein described with reference to and as shown in the accompanying drawings.