WO1989011438A1

WO1989011438A1 - Lifting apparatus designed e.g. for the lifting of an automobile

Info

Publication number: WO1989011438A1
Application number: PCT/FI1989/000091
Authority: WO
Inventors: Toivo Mäkelä
Original assignee: Maekelae Toivo
Priority date: 1988-05-19
Filing date: 1989-05-18
Publication date: 1989-11-30
Also published as: FI82910B; FI891622A0; FI891622A; FI82910C; AU3686789A; EP0378610A1

Abstract

Lifting apparatus designed e.g. for the lifting of an automobile, said lifting apparatus comprising a frame (1) and a lifting mechanism mounted in the frame and consisting of at least one power means (5) and at least one lifting means (6). The apparatus has a transmission member (7) which is pivoted on the frame so that it turns in an essentially horizontal plane, and a power means (5), one end of which is pivoted on the frame (1) and the other end (9) on the transmission member (7). The transmission member and thelifting means (6) are linked by a connecting member (10), which is also mounted on pivots. The construction of the apparatus allows the entire lifting mechanism to be contained in the space inside the frame.

Description

LIFTING APPARATUS DESIGNED E.G. FOR THE LIFTING OF AN AUTOMOBILE

The present invention relates to a lifting apparatus designed e.g. for lifting an automobile, said lifting apparatus comprising a frame and a lifting mechanism mounted in the frame and consisting of at least one power means and at least one lifting means.

Certain previously known apparatuses designed for the lifting of an automobile must, because of their height, be mounted in a pit in the floor of the garage, below the floor level, to enable an automobile to be brought onto the apparatus. This is a very expensive solution which has the additional drawback that, being mounted in a pit, the apparatus is fixed in a given place.

Another previously known lifting apparatus consists of four columns anchored in the garage floor, one at each corner of the apparatus. Each column is provided with a swivelled lifting arm which turns horizontally and has an adjustable lifting part whose distance from the column can be varied. The lifting arm moves up and down the column during the lifting and lowering operations. This solution is also expensive and requires plenty of room. A further drawback is that this apparatus, too, is fixed in one place. Besides, the columns at the corners are obstacles to repair and painting operations.

There are also fairly small, movable lifting apparatuses which are first pushed in under the vehicle, whereupon the lifting arms are spread out to suitable parts of the vehicle body by which it can be lifted. The drawback is that it is very difficult to position the lifting arms in the narrow space under the vehicle. In addition, due to this difficulty, it may happen that one of the lifting arms is ill positioned, involving the risk of damaging the bottom of the vehicle body.

The object of the present invention is to eliminate the drawbacks observed in the aforementioned solutions and to achieve an easy-to-use, reliable and low-cost lifting ap¬ paratus for the lifting of automobiles e.g. during repairs and painting. The lifting apparatus of the invention is characterized in that it has a transmission member pivoted on the frame and turning in an essentially horizontal plane, and that one end of a power means is pivoted on the frame and the other end on the transmission member, and that it comprises a connecting member, one end of which is pivoted on the transmission member and the other end on a lifting means. The advantage is a good alignment of the forces, allowing a compact construction, and that the lifting mechanism is placed inside and protected by the frame.

A preferred embodiment of the invention is characterized in that the lifting means consists of at least two lifting legs placed at a suitable distance from each other, at least one bracing member placed between the legs, bearing rollers, and at least one lug for the mounting of a connecting member. The advantages are an even distribution of lifting power in the apparatus and the conversion of sliding friction into rolling friction during the lifting.

Another preferred embodiment of the invention is character¬ ized in that the lifting leg as seen from above is a plate¬ like body of essentially even thickness, which, as seen from the side, has a first end, a bend and a second end, said lifting leg having a width that increases steadily from the first end towards the bend and then decreases again towards the second end, the width being largest at the level of the bend. This construction provides the considerable advantage that the lifting operation can be performed in two phases. The lifting power needed in the preliminary lifting phase has been reduced by shortening the lever arm of the lifting leg so that the lever arm extends from the bend, which rests on the floor, to the joint on which the leg turns. However, a larger lifting height is required than is possible to achieve in this manner. In the second phase, therefore, after the length of the lever arm of the lug in which the connecting member is mounted has become more favourable, the end of the lifting leg touches the floor. As a result, the length of the lever arm constituted by the lifting leg increases and more power is needed. Correspondingly, a larger lifting height is achieved.

A third preferred embodiment of the invention is characterized in that the second end of the lifting means is attached to an essentially horizontal shaft mounted with bearings on the frame so that it can turn about its centre axis, said shaft being provided with two lugs for each connecting member, said lugs being mounted at an angle to the frame and provided with a hole for the joint of a connecting member in such manner that the joint of the connecting member is located below and at a maximal distance from the the joint of the lifting means. Due to the maximized vertical distance between said joints, this construction provides the advantage that the lever arm of the connecting member relative to the joint of the lifting means becomes as long as possible.

A fourth preferred embodiment of the invention is characterized in that the apparatus comprises two lifting means, two power means and two connecting members, which are placed symmetrically relative to each other in a mirror-image configuration relative to the transverse and longitudinal axes of the lifting apparatus and in such manner that when the power means, via the mediation of the transmission member and the connecting member, exerts a pull at the lugs of the lifting means, the bearing rollers at the bend of the leg are the first to touch the base, e.g. floor, and as the power means continues to pull at the lifting means, the bearing rollers at the end the leg touch the floor, so that when the lifting means is turned further about its pivot, the bearing rollers at the bend of the leg rise clear of the floor. The arrangement has the advantages of a minimized need for power and a compact construction. The construction makes it possible to divide the lifting operation into a preliminary phase and a main lifting phase, the latter following immediately upon the former, in such manner that the power available is optimized.

Yet another preferred embodiment of the invention is characterized in that the transmission member consists of two plates, of which one is placed on top of the other at a distance from it, the first ends of the power means and connecting member being pivoted in the space between the two plates, and that the transmission member turns about a vertical pivot which is attached to the underside of the top plate of the frame by means of a fixing part, the lower end of the pivot being provided with a supporting plate to carry the weight of the transmission member. The advantages are a good alignment of the forces and a low-profile construction.

A still further preferred embodiment of the invention is characterized in that the geometry of the lifting mechanism, the locations of the joints and the leverage relations are so chosen that, when the lifting apparatus is in the low position, the entire lifting mechanism is contained in the space surrounded by the top plate, end plates and side plates of the frame. The advantage is, in addition to a good alignment of ^' the forces and a low-profile construction, that the lifting mechanism is protected by the frame. The invention is described in the following by the aid of an example with reference to the drawings attached, wherein

Fig. 1 presents the lifting apparatus as seen oblique¬ ly from the front and from above.

Fig. 2 presents a top view of the lifting apparatus in the low position with the top plate removed.

Fig. 3 presents a top view of the lifting apparatus in the high position with the top plate removed.

Fig. 4 presents a lateral view of the lifting apparatus in the high position and sectioned along line IV-IV in Fig.2

Fig. 5 presents a lateral view of the lifting appara¬ tus in the final stage of the preliminary lift¬ ing phase and partly sectioned and simplified.

Fig. 6 presents a lateral view of the lifting appara¬ tus in the high position and sectioned along line VI-VI in Fig.3

Fig. 7 presents a front view of the transmission member as seen from the direction of line VII-VII in Fig.2

The lifting apparatus has a frame 1 of the form of a rectangular box without a bottom. The frame consists of a horizontal top plate 2 and end plates 3 and side plates 4 attached to its edges at right angles to the top plate. The height of the end plates and side plates has been minimized so as to achieve a construction of minimal height. Attached to the inside of each side plate 4 is a lug 30 for the joint 21 holding the second end 9 of a power means 5. The power means is an ordinary hydraulic cylinder. Seen from above, the lugs 30 are located symmetrically relative to the transverse and longitudinal axes of the frame, one on each side of each axis. Also attached to the inside of each side plate 4 are two sleeve bearings 29 which are also located symmetrically relative to the transverse and longitudinal axes of the frame. The sleeve bearings 29 are placed closer to the ends of the frame than the lugs 30.

At the midpoint of the frame as seen from above is a vertical pivot 19, which is attached to the underside of the top plate 2 by means of a fixing part 23. The pivot 19 accommodates the bearing of the transmission means 7, which turns horizontally about the pivot. Below the transmission member, attached to the lower end of the pivot 19, is a bearing plate 24 which carries the weight of the transmission member and prevents it from falling off the pivot. The transmission member 7 consists of two plates of identical shape, one of which is placed on top of the other at a suitable distance. The thickness of the plates and the distance between them are so chosen that the transmission member is entirely inside the frame as seen from the side. At each end of the transmission member, symmetrically relative to the pivot 19, is a vertical pivot 20 for the joint holding the first end 8 of a power means 5. The positions of the pivots 20 and the lugs 30 relative to each other are so chosen that the power means 5 is in an essentially horizontal position and, seen from the side, completely inside the frame. Between the central pivot 19 and the pivots 20 at the ends of the transmission member are another two pivots 15 placed symmetrically on either side of the central pivot 19. Seen from above, all the pivots 20, 15 and 19 are located on the same straight line, which is the centre line of the transmission member.

The lifting apparatus has two symmetrical lifting means 6 placed near the ends of the apparatus. Each lifting means 6 consists of a pair of parallel lifting legs 13 placed at a distance from each other, a shaft 28 placed transversely between the legs, a lighter bracing member 14, bearing rollers 17 and 18 and lugs 22. Seen from above, the lifting leg is a plate-like body of uniform thickness. Seen from the side, the upper edge of the lifting leg is straight and of a length equal to the length of the leg itself. At the end 26 connected to the shaft 28, the width of the leg is about equal to the diameter of the shaft. From this end towards the other end 25, the width of the leg increases until it culminates at the level of the bend 27. From this point towards the end 25, the lower edge rises steadily towards the upper edge.

One end 26 of the lifting leg is attached to the shaft 28, at a point close to its end, and the shaft ends in turn are mounted with sleeve bearings 29 on the frame of the lifting apparatus. Attached to the shaft, near one of its ends, are two lugs 22 which, when the lifting apparatus is in the low position, point in a direction downwards from the shaft 28 and outwards from the transmission member in the longitudi¬ nal direction of the frame 1 , thus forming a sharp angle to the vertical plane passing through the shaft 28. This angle is in the range 30° - 60°. When the lifting apparatus is in the high position, the lugs 22 still point in a downward direction, but the angle is now such that the lugs also point toward the transmission member 7 while forming a sharp angle relative to the vertical plane passing through the shaft 28. In this case, too, the magnitude of the angle is in the range 30° - 60°, but the angle is now on the other side of said vertical plane. In the low position of the lifting apparatus, the lugs 22 are entirely inside the frame. Between the lower ends of the lugs is a horizontal pivot 16, whose vertical distance to the shaft 28 is as large as possible so as to provide a maximal moment arm between pivots 16 and 29 in order to reduce the need for lifting power.

The lifting leg 13 is provided with two bearing rollers 17 placed side by side at the first end 25 of the leg and another pair of rollers 18 at the bend 27 of the leg. The bearing rollers are mounted with bearings on either side of the leg and their function is to convert sliding friction into rolling friction during the lifting. Especially rollers 17 move through a fairly long distance during the main lifting phase after the preliminary phase. The bearing rollers are needed in the first place because the apparatus has two lifting means which act in opposite horizontal directions. The bracing bar 1 between the legs is placed close to the first end 25, where it adequately reinforces the narrower ends of the legs.

Between the transmission member 7 and each lifting means 6 is a connecting member 10, the first end 11 of which is mounted on pivot 15 and the other end on pivot 16. The connecting member is a flat bar whose first end, as seen from the side, is located somewhat higher up than the second end. The function of the connecting members is to transmit the lifting power produced by the power means 5 from the transmission member to the lifting means 6.

Due to the geometry of the device, a much larger lifting power is needed at the initial stage of the lifting operation than at its final stage when pivot 16 has moved lower relative to pivot 29 and the moment arm for the power means has grown longer. Since the lifting power is limited, a specific preliminary lifting phase is needed, during which the moment arm of the supporting forces directed against the floor is shortened, relative to pivot 29. The geometry of the lifting leg makes this possible. At first, the moment arm of the supporting forces is short, extending from the bearing rollers 18 at the bend 27 of the leg to the joint 29. As the lifting motion continues and the power means 5 exerts a thrust on the transmission member 7, the connecting member 10 exerts a pull on pivot 16, so that bearing rollers 18 rise clear of the floor and the rollers 17 at the ends of the legs begin to bear the load. This means that the lever arm of the supporting forces becomes longer, but at the same time the length of the moment arm between joints 16 and 29 has also increased, so that the lifting operation is possible. It is obvious to a person skilled in the art that the invention is not restricted to the example described above, but that it may instead be varied in the scope of the following claims. Thus, for instance, the lifting leg may be suitably curved in lateral profile to achieve a more even distribution of the lifting force. Also, the function of the connecting member can be performed by a chain or rope instead of a drawbar, because, due to the load, this member is not required to transmit thrust. Further, the geometry of the transmission member and the relative positions of the pivots on it may vary according to the lifting result desired.

Claims

1. Lifting apparatus designed e.g. for the lifting of an automobile, said lifting apparatus comprising a frame (1) and a lifting mechanism mounted in the frame and consisting of at least one power means (5) and at least one lifting means (6), c h a r a c t e r i z e d in that the apparatus has a transmission member (7) pivoted on the frame and turning in an essentially horizontal plane, and that one end (8) of the power means (5) is pivoted on the frame (1) and the other end (9) on the transmission member (7), and that it comprises a connecting member (10), one end (11) of which is pivoted on the transmission member and the other end (12) on a lifting means (6) .

2. Lifting apparatus according to claim 1, c h a r a c ¬ t e r i z e d in that the lifting means (6) consists of at least two lifting legs (13) placed at a suitable distance from each other, at least one bracing member (14) placed between the legs, bearing rollers (17, 18), and at least one lug (22) for the mounting of a connecting member.

3. Lifting apparatus according to claim 1 or 2, c h a r ¬ a c t e r i z e d in that the lifting leg (13) as seen from above is a plate-like body of essentially even thickness, which, as seen from the side, has a first end (25), a bend (27) and a second end (26), said lifting leg having a width that increases from the first end (25) towards the bend (27) and then decreases again towards the second end (26), the width being largest at the level of the bend (27) .

4. Lifting apparatus according to claim 1 , 2 or 3, c h a r a c t e r i z e d in that one end (26) of the lifting means is attached to an essentially horizontal shaft (28) supported by its ends by bearings (29) mounted in the frame (1) so that it can turn about its centre axis, said shaft (28) being provided with two lugs (22) for each connecting member, said lugs being provided with a hole for the joint (16) of a connecting member (10) in such manner that the pivot (16) of the joint of the connecting member is located below and at a maximal distance from the pivot (29) of the joint of the lifting means.

5. Lifting apparatus according to any one of the preceding claims, c h a r a c t e r i z e d in that the apparatus comprises two lifting means (6), two power means (5) and two connecting members (10), which are placed symmetrically relative to each other in a mirror-image configuration relative to the transverse and longitudinal axes of the frame (1) of the lifting apparatus and in such manner that when the power means, via the mediation of the transmission and connecting members, exerts a pull at the lugs (22) of the lifting means, the bearing rollers (18) at the bend of the leg are the first to touch the base, e.g. floor, and as the power means continues to pull at the lifting means, the bearing rollers (17) at the first end hit the floor, so that, when the lifting means is turned further about its pivot (29), the bearing rollers (18) at the bend of the leg rise clear of the floor.

6. Lifting apparatus according to any one of the preceding claims, c h a r a c t e r i z e d in that the transmission member consists of two plates (7), of which one is placed on top of the other at a distance from it, the first ends of the power means (5) and connecting members (10) being pivoted in the space between the two plates, and that the transmission member turns about a vertical pivot (19) which is attached to the underside of the top plate (2) of the frame by means of a fixing part (23), the lower end of said pivot being provided with a supporting plate (24) placed below the transmission member to carry the weight of the latter.

7. Lifting apparatus according to any one of the preceding claims, c h a r a c t e r i z e d in that the geometry of the lifting mechanism, the locations of the joints and the leverage relations are so chosen that, when the lifting apparatus is in the low position, the entire lifting mechanism is contained in the space surrounded by the top plate (2) , end plates and side plates (4) of the frame.