Bearing arm arresting for a vehicle lifting device

Abstract: The invention relates to a vehicle lifting device comprising at least one column (2), with a vertically movable carriage (3) provided with a support (7) to which bearing arms (8) for supporting a vehicle are mounted for swivelling about a vertical swivel shaft (68) and drive means for moving the carriage (3) upward along the column (2). Each arm (8) is provided with an arresting for locking same in a selected swivel position, comprising a first tooth member (61) connected non-rotatably to the support (7), a second tooth member (69) connected non-rotatably to the arm (8), which tooth members (61,69) are provided with co-acting toothing (57,79) coaxially with the swivel shaft (68) and wherein at least one (69) of the tooth members (61,69) is mounted for axial disengagement from the other (61) by releasing means. At least at the height of the swivel shaft (68) the bearing arm (8) has a rectangular profile (58). The arresting is arranged in the interior of the hollow bearing arm (8), wherein the tooth member (69) connected non-rotatably to the bearing arm (8) is accommodated in a holder (69) with two parallel side walls (70,71) which lie slidably against two parallel vertical wall parts of the rectangular profile (58) of the bearing arm (8) and the releasing means engage onto this tooth member (69).

Description: The invention relates to a vehicle lifting device comprising at least one column, with a vertically movable carriage provided with a support to which bearing arms for supporting a vehicle are mounted for swivelling about a vertical swivel shaft and drive means for moving the carriage upward along the column, wherein each arm is provided with arresting means for locking same in a selected swivel position, comprising a first tooth member connected non-rotatably to the support, a second tooth member connected non-rotatably to the arm, which tooth members are provided with co-acting toothing coaxially with the swivel shaft and wherein at least one of the tooth members is mounted for axial disengagement from the other by release means, at least the portion of the bearing arm receiving the swivel shaft having a rectangular profile. Such lifting devices are generally known. These can be embodied as a one- or two-column lifting device having fixed columns placed at the sides or as a jack lifter with one telescopically extending column. In such a vehicle lifting device, known from DE-A-3 026 160, the tooth member connected to the support is mounted fixedly on top of the support, while the tooth member connected to the arm is connected to this arm via a support protruding from the arm to above the support. The drawback to this known vehicle lifting device is that because of the arresting mechanism the construction at the location of the swivel shaft is voluminous and does not provide an attractive appearance, while the arresting mechanism is vulnerable and can form an awkward obstruction, particularly since the door of an automobile placed on the lifting device can strike against this arresting mechanism. The invention now has for its object to provide a vehicle lifting device of the type described in the preamble which does not have these drawbacks. In a lifting device according to the invention this object is achieved in that the arresting means is arranged in the interior of the hollow bearing arm, wherein the tooth member connected non-rotatably to the bearing arm is accommodated in a holder with two parallel side walls which lie slidably against two parallel vertical wall parts of the rectangular profile of the bearing arm and the release means engage onto this tooth member. Due to the direct co-action of the holder with the profile of the bearing arm it is therefore possible to accommodate the arresting enclosed in the bearing arm. The arresting is hereby protected against damage and moreover forms no obstruction. The swivel construction of the bearing arm furthermore acquires a smooth and attractive appearance. A simple and therefore economic construction is moreover achieved owing to the direct co-action of the holder with the bearing arm. A further development of the lifting device according to the invention is characterized in claim 2. This construction has the advantage that it is very simple to assemble. The hub of the tooth member connected to the support simultaneously forms the swivel bearing for the bearing arm. Use of the step of claim 3 achieves the advantage that the tooth member connected to the support is held simply in place by the shaft so that only operations for fixing the construction, particularly arranging bolts on the outside, have to be carried out. A further step very favourable in this respect is characterized in claim 4. In preference the step of claim 5 is applied here. When the bearing arm is moved wholly downward, the lower pin protruding beneath the support is pressed upward relative to the arm through the lower pin making contact with the ground, whereby the holder is released with the associated tooth member from the tooth member connected to the support. Therefore as soon as the bearing arms of the lifting device are moved into the lowest position the arms are freely rotatable. When the lifting device is set into operation and the bearing arms moved upward the arresting automatically comes into operation again. By employing an upper pin as according to claim 6, the releasing can also be brought about manually. This is favourable for instance when the automobile for lifting has a large ground clearance and for correct setting of the swivel position of the bearing arms the carriages with the bearing arms have to be moved slightly upward. A favourable, compact embodiment of the arresting mechanism is obtained with the step of claim 7. When therein the step of claim 8 is applied it is achieved in favourable manner that, if the arresting should jam in some way or another, the downward movement of the bearing arms cannot be obstructed when the lower pin comes into contact with the ground. When the arresting is jammed and the bearing arm is moving downward, the spring will be compressed and the transverse pin and the holder connected thereto will thus be loaded in upward direction. When the jamming is eliminated, for instance by briefly pushing back and forth against the bearing arm, the holder will still move upward under the influence of the spring force and release the arresting. The invention will be further elucidated in the following description with reference to the embodiment shown in the figures. Fig. 1 shows a partially broken away perspective view of an embodiment of a vehicle lifting device according to the invention. Fig. 2 shows on a larger scale a partially broken away view according to arrow II in fig. 1. Fig. 3 shows on a larger scale a partially broken away view according to arrow III in fig. 1. Fig. 4 shows an exploded view with components of the parts designated with arrow IV in fig. 3 Fig. 5 shows a section according to arrow V-V in fig. 3 in the released situation of the arresting mechanism. Fig. 6 shows a view corresponding with fig. 5 wherein the arresting mechanism is in the locked situation. The vehicle lifting device 1 according to the invention shown in fig. 1 comprises two hollow columns 2 of sturdy steel plate, which have a substantially C-profile as shown particularly in fig. 3. Each column 2 thus has a channel 4 on one side. Each column 2 is fixedly welded onto a base plate 11 which is anchored in the ground using bolts 12. Received into each hollow column 2 is a vertically movable carriage 3 which is provided at its bottom end and top end with guide wheels 5 and 6 respectively. The basic body of the carriage 3 consists of a U-profile. The construction is such that the body of the U-profile of the carriage 3 lies in the channel 4 of the column 2 such that it lies in one plane with the profile parts of the column 2 adjoining the channel 4. On the bottom end each carriage 3 bears a support construction 7 which protrudes outside the column 2 and to which two bearing arms 8 are pivotally mounted. Integrated into the swivel bearings 10 is an arresting mechanism which can lock the relevant arm 8 in a chosen swivel position. Situated on the end of an extending portion of each arm 8 further shown in fig. 3 is a carrier 9, the top surface of which can grip a support on the bottom of a vehicle for raising. To lift a vehicle the arms 8 are swivelled into such a position and extended so far until all four carriers 9 of the lifting device 1 are situated under a relevant support of the vehicle so that the vehicle can be lifted by the simultaneous movement of the two carriages 3 in both columns 2. For synchronous upward movement of the carriages 3 the lifting device 1 is provided with drive means. In the embodiment shown these drive means comprise a hydraulic jack 14 mounted in the left-hand column 2 in fig. 1. The cylinder 15 of this jack 14 is fixedly connected to the carriage 3 and the piston rod 16 is fixedly connected at its top end to the column 2. The piston rod 16 has a central bore 36 to the outer end of which is connected a hydraulic oil feed 17. For lifting, hydraulic oil under pressure is pressed via the feed 17 and the bore 36 above the piston into the cylinder 14 whereby the cylinder 14 and therefore the carriage 3 are moved upward. For synchronous driving of the carriage 3 in the right-hand column 2 in fig. 1 a chain transmission is arranged. This chain transmission comprises a chain 19 which is fixedly mounted on a support 18 forming an entity with the carriage 3. The chain 19 extends downward from this support 18 and runs around a chain wheel 20 that is rotatable about a shaft fixedly connected to the column 2. From the chain wheel 20 the chain extends upward via a chain wheel 21 at the top of the left-hand column 2 through a cross beam 13 mutually joining both columns 2 at their top ends, over a chain wheel 22 at the top of the right-hand column 2 to the right-hand carriage 3. The end of the chain 19 is fixedly connected to the carriage 3 by means of a safety construction 23 not further shown in fig. 2. This safety construction 23 is embodied such that if the chain 19 should break the rod 24 mounted fixedly in the column 2 is gripped immediately, thus preventing the right-hand carriage 3 from falling downward. Integrated into the left-hand column is a safety device which, during normal use, also prevents undesired downward movement of the carriages 3, for example as a result of a leakage in the hydraulic jack 14. This safety device comprises a hole strip 27 mounted fixedly in the left-hand column with which a ratchet 28 co-acts that is connected pivotally to the left-hand carriage 3 by means of a shaft 29. The ratchet 28 is embodied such that it allows an upward movement but in the case of downward movement grips into a hole in the hole strip 27. To be disengaged from the hole strip 27 the ratchet 28 can be rotated round the shaft 29 in counter-clockwise direction as seen in fig. 2 by an electromagnet 30. This electromagnet 30 is activated when the control device, which is not described further here, receives a command to lower the lifting device. The described chain transmission ensures that both carriages 3 run synchronously unless, as described, the chain breaks. The right-hand carriage 3 is then instantaneously locked on the rod 24. Chain breakage is moreover detected by a switch means, not further described here, and this switch means generates a signal to the control device whereby the lifting or lowering movement is immediately ended. Thus is prevented that an automobile resting on the bearing arms comes to hang at a slant and possibly falls from the arms. The mentioned switch means likewise detects when the chain 19 becomes slack. This can occur when during lowering the right-hand carriage is obstructed by a support or the like accidentally left behind under the device. The lowering movement will in this case also be switched off immediately. These safety devices are otherwise generally per se known. Another per se known safety device is a sensor wire 37 arranged directly beneath the cross beam 13 which activates a switch as soon as the wire 37 is pressed upward, for example by the roof of a vehicle. To prevent damage through contact with the cross beam 13 the lifting movement is then immediately switched off. Fig. 3 shows that the basic part 40 of the arm 8 is received in the support 7 which forms an entity with the carriage 3. The support 7 is formed here by a top plate 60 and a bottom plate 59. The portion of the arm 8 received between these plates 59, 60 is a rectangular profile 58, as is shown particularly clearly in fig. 5 and 6. This profile part 58 can either be a separate part to which the remaining part of the basic arm is fixedly welded or can form part of the profile of the basic arm 40 itself. The arresting for fixing the swivel arm 8 in a desired swivel position is accommodated in the rectangular profile part 58. The arresting comprises a first tooth member 61 that is connected non-rotatably to the support 7. This non-rotatable connection is effected in that the tooth member 61 has on its bottom end a non-round, and particularly a square hub portion 65 which falls into a square hole 64 of plate 59. Above the square prismatic portion 55 the hub is provided with a cylindrical portion 66 which fits into a cylindrical hole in the bottom wall 63 of the basic arm 40. The hub portion of the tooth member 61 is of steel according to this embodiment, while the actual toothing 57 is formed on the outer periphery of a moulded-on plastic part 62. This plastic part is of a high-grade plastic such as a glass fibre-reinforced polyamide or polyarylamide. The toothing 57 is arranged as a conical surface. Formed in the top of the tooth member 61 is a cylindrical casing 76 into which a shaft 68 is close-fittingly received. The shaft 68 protrudes with a slide fitting through a hole 81 in the top wall of the basic arm 40 and engages in a similar hole in the top plate 60 as shown in fig. 5 and 6. The shaft 68 is enclosed in vertical direction using a plate 82 fixed onto the upper plate 60 with bolts. The swivel bearing for the bearing arm 8 is therefore formed on the underside by co-action between the cylindrical part of the tooth member 61 and the cylindrical hole in the bottom plate 63 and at the top by the co-action of the shaft 68 with the hole 81 in the top wall 83 of the arm. In addition to the tooth member 61 connected non-rotatably to the support 7 the arresting contains a tooth member 69 connected non-rotatably to the bearing arm. This tooth member is accommodated in a holder 69 which is manufactured in this embodiment from plastic and has a conical inner surface with toothing 79 that is complementary to the toothing 57 of the tooth member 61. The holder 69 has two parallel side walls 70, 71 lying slidably against two opposite parallel vertical wall parts of the rectangular profile part 58. The holder 69 can therefore slide vertically in the profile part 58 but cannot rotate therein. The holder 79 likewise slides over the shaft 68. It will be apparent that, when the holder 69 is moved downward and the toothing 79 thereof engages with the toothing 57 of tooth member 61, the bearing arm cannot swivel about the shaft 68. This situation is shown in fig. 6. To release the arresting and to enable rotation of the arm 8 into a desired swivel position, releasing means are arranged which can move the holder 69 upward clear of the tooth member 61. These releasing means are two-fold in the embodiment shown here. The connection to the holder 69 is formed by a transverse pin 73 gripping in openings in the holder 69 and extending through a slot-like opening 72 in the shaft 68. The shaft 68 is further provided with a central bore 84. An upper pin 74 and a lower pin 77 protruding respectively above the top plate and beneath the bottom plate 59 of the support 7 can grip through this bore onto the transverse pin 73 and therefore onto the holder 69. As is shown clearly in fig. 5 and 6, the upper pin 74 protrudes through the transverse pin 73 and arranged on the bottom end of the upper pin 74 is a locking ring which can grip beneath the transverse pin 73. By pulling on the hand-grip in the form of a knob 75 arranged on the top end of the upper pin 74 the holder 69 can be moved upward and disengaged from the position shown in fig. 6 in engagement with the lower tooth member 61. In addition to the upper pin 74 which is intended for manual operation, the releasing means also comprise a lower pin 77 which provides an automatic release as soon as the bearing arm is moved into its lowest position. This lower pin 77 is embodied in this embodiment as a tube 77 with a slot 78 through which the transverse pin 73 likewise extends. Arranged in the tube 77 is a coil spring 80 which grips on the underside onto a locking spring (not shown) in the interior of tube 77 and which lies at its top end against the transverse pin 73. As soon as the bearing arm 8 moves downward from the position of fig. 6 to the position of fig. 5 the bottom end of the lower pin 77 comes into contact with the base plate 11 so that the lower pin 77 is pressed upward relative to the arm. Via the spring 80 an upward force is now exerted on the transverse pin 73 and therefore on the holder 79, whereby the toothing 79 of the holder 69 is released from the toothing 57 of the tooth member 61. The arm is now, in the situation of fig. 5, freely pivotable. Should the toothings jam onto one another whereby the holder 69 will not slide freely upward, then only the spring 80 will be tensioned, while the downward movement of the arm 8 is not obstructed and there is not the resulting danger that an automobile supported on the carriers 9 of the arms of the lifting device comes to lie at a slant. As soon as the jamming is eliminated, the holder 69 will then still be pressed upward by the force of the spring 80 and the arresting brought to an end. In the reverse movement, from the situation of fig. 5 to that of fig. 6, the spring 76 arranged round the upper pin 74 presses downward the transverse pin 73 and therefore the holder 69 until the toothing 79 thereof is in engagement with the toothing 57 of the tooth member 61. The arresting is once again brought into effect at that moment. The assembly of the arresting mechanism is very simple. The rectangular profile part 58, or in a relevant embodiment the end of the arm 8, is placed between the bottom plate 59 and the top plate 60 of the support 7, as yet without any components of the arresting mechanism. Via the open rear end of the arm 8 the tooth member 61 is subsequently placed through the opening in the bottom wall 63 and its square prismatic portion is placed into the corresponding opening 64 in the bottom plate 59. The holder 69 is then placed on the tooth member 61 and the shaft 68 is inserted from above into the casing 76 in the tooth member 61 through the opening in the top plate 60 and the opening 81 in the top wall 83 of the arm 8. The lower pin 77 is subsequently pushed from below into the central bore of the shaft and the transverse pin 73 can be brought into position. After mounting of the upper pin 74 and the spring 76 the cover 82 is screwed into place with which both the bearing mounting and the arresting are mounted fixedly in their positions. The spring 80 can be arranged afterward. The invention is not limited to the embodiment shown in the figures and described above. Many embodiment variants fall within the scope of the appended claims.

Claims: Vehicle lifting device comprising at least one column (2), with a vertically movable carriage (3) provided with a support (7) to which bearing arms (8) for supporting a vehicle are mounted for swivelling about a vertical swivel shaft and drive means (14) for moving the carriage (3) upward along the column (2), wherein each arm (8) is provided with arresting means for locking same in a selected swivel position, comprising a first tooth member (61) connected non-rotatably to the support (7), a second tooth member (69) connected non-rotatably to the arm (8), which tooth members (61, 69) are provided with co-acting toothing (57, 79) coaxially with the swivel shaft and wherein at least one of the tooth members is mounted for axial disengagement from the other by releasing means, at least the portion (58) of the bearing arm (8) receiving the swivel shaft having a rectangular profile, characterized in that the arresting means is arranged in the interior of the hollow bearing arm (8), wherein the tooth member connected non-rotatably to the bearing arm (8) is accommodated in a holder (69) with two parallel side walls which lie slidably against two parallel vertical wall parts of the rectangular profile (58) of the bearing arm (8) and the releasing means engage onto this tooth member (69). Lifting device as claimed in claim 1, characterized in that the support (7) comprises two plates (59, 60) lying one above the other and that the bearing arm (8) with the rectangular profile (58) fits between these plates, and that the tooth member (61) connected non-rotatably to the support (7) is provided with a hub with a cylindrical wall part (66) that fits into a cylindrical hole in a horizontal wall (63) of the bearing arm and a non-round prismatic part (65) which protrudes outside this cylindrical part (66) and fits into a corresponding non-round prismatic hole (64) in the plate (59) of the support lying against the wall (63). Lifting device as claimed in claim 2, characterized in that the tooth member (61) connected to the support (7) has a casing (76) in which is received a shaft (68) mounted on the opposite plate (60) and placed through the opposite horizontal wall and wherein the tooth member (79) accommodated in the holder (69) is slidable about this shaft. Lifting device as claimed in any of the foregoing claims, characterized in that the tooth member (61) connected to the support (7) is mounted at the bottom of the arm (8) and the tooth member accommodated in the holder (69) is constrained vertically downward by resilient means (76). Lifting device as claimed in claim 4, characterized in that the releasing means comprises a lower pin (77) connected to the holder (69) and protruding outward beneath the support (7). Lifting device as claimed in claim 4 or 5, characterized in that the releasing means comprises an upper pin (74) provided with a hand-grip (75), connected to the holder and protruding outward above the support (7). Lifting device as claimed in claim 5 or 6, characterized in that the upper (74) and/or lower pin (77) are received in a central bore (84) of the shaft (68) and that the shaft is provided with a vertical slot (72) through which extends a transverse pin (73) gripping the holder (69) and connected to the pins (74, 77). Lifting device as claimed in claim 7, characterized in that the lower pin (77) is provided with a vertical slot (78) through which the transverse pin (73) extends and that a spring (76) is arranged constraining the lower pin (77) downward relative to the transverse pin (73).

Inventors: BERENDS JAN, FIJNVANDRAAT JAN WILLEM, BERENDS, JAN, FIJNVANDRAAT, JAN WILLEM
Applicants: STERTIL BV, STERTIL B.V.
Application year: 1991
Main classification: B66F7
IPC codes: B66F7