WO2003022724A1

WO2003022724A1 - Jack

Info

Publication number: WO2003022724A1
Application number: PCT/IB2002/003397
Authority: WO
Inventors: Hermanus Johannes Pieterse
Original assignee: Econo-Patents (Pty) Ltd
Priority date: 2001-09-07
Filing date: 2002-08-23
Publication date: 2003-03-20

Abstract

A jack (10;76;102;144) for lifting an axle (14;152) of a vehicle (94) is disclosed. The jack (10;76;102;144) comprises a lifting head (12;124;154) for supporting the vehicle's axle (14;152), the lifting head (12;124;154) being connected to a pivot arm assembly (26;78;104;146). The pivot arm assembly (26;78;104;146) is pivotally mounted to a pedestal arrangement (44;106) comprising a base plate (46;90;108;148) and a U-shaped housing (48;80), so that the lifting head (12;124;154) is pivotable between an inoperative, lowered position and an operative, raised position, in which the axle (14;152) is lifted, by moving the vehicle (94) relative to the base plate (46;90;108;148). The housing (48;80) includes a pair of side walls (50,52;110,112), for receiving the pivot arm assembly (26;78;104;146), and a rear wall (62;100) against which the pivot arm assembly (26;78;104;146), in its raised, engaged position, abuts. Significantly, the pivot arm assembly (26;78;104;146) is arranged so that when it pivots to its raised position, the assembly (26;78;104;146) traverses an angle greater than 90°, so that in its raised position, the assembly (26;78;104;146) is locked in an over centre configuration.-1-

Description

JACK

BACKGROUND OF THE INVENTION

THIS invention relates to a jack for raising the axle of a vehicle, such as a trailer or a motor vehicle.

A typical jack comprises a lifting head that is arranged to locate under the vehicle's axle, and which can be manually raised and lowered so as to raise and lower the vehicle. These manually operated mechanical jacks, however, are generally cumbersome and time-consuming to operate. In addition, they can only be used for a specific type of vehicle.

It is therefore desirable to provide a jack that can be easily installed and operated, and that can be used on a variety of different vehicles. SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a jack for lifting an axle of a vehicle, the jack comprising:

a lifting head for engaging the axle;

a support post extending from the lifting head;

a base assembly; and

pivoting mounting means for pivotally mounting the support post to the base assembly so that the lifting head is pivotable between an inoperative, lowered position and an operative, raised position, in which the axle is lifted, by moving the vehicle relative to the base assembly.

Typically, the base assembly includes a base plate and a housing fitted to the base plate, the housing accommodating the support post and including the pivoting mounting means.

In one version, the housing includes a rear wall and a pair of side walls, each side wall defining a slot for receiving a pivot pin, which extends through a pair of lower apertures defined in the support post, the combination of the slots and the pivot pin defining the pivoting mounting means.

In an alternative version, the housing includes a rear wall and a pair of side walls, with a pair of axle receiving blocks being fitted adjacent each side wall for pivotally capturing a pair of stub axles that extend from either side of the support post, the combination of the axle receiving blocks and stub axles defining the pivoting mounting means. Conveniently, the rear wall of the housing defines stop means, against which the support post, in the operative, raised position abuts so as to define an over centre configuration. In particular, the over centre configuration is defined by the rear wall, which defines an angle between itself and the base plate of approximately 85°.

In yet a further version, the housing includes a pair of spaced apart support arms, with a pivot axle extending between the support arms for pivotally receiving a sleeve that is fitted to the support post, the combination of the pivot axle and sleeve defining the pivoting mounting means. Conveniently, in this version, the jack further includes a stop plate that extends from, and is pivotable with, the support post, the stop plate being shaped so as to define the stop means, so that in the raised, engaged position the stop plate and thus the support post abuts against the base plate in the over centre configuration.

Advantageously, at least one intermediate connecting element extends between the lifting head and the support post and/or between the support post and the base assembly for allowing the overall height of the jack to be varied.

Preferably, the jack further includes at least one tread that is connectable to the base assembly, the tread extending from the base assembly so as to define a track upon which the wheels of the vehicle may drive, so that in use as the vehicle approaches the jack the wheels of the axle that is not being lifted anchors the tread and thus the jack in position, so as to allow the other axle to firmly engage and be lifted by the lifting head of the jack.

Conveniently, the lifting head includes a cup for accommodating the axle, the cup being pivotable relative to the support post. Typically, the lifting head includes a substantially flat platform and a pair of upwardly extending arms for snugly accommodating the axle.

Advantageously, the jack includes locking means for locking the support post in its raised position.

Preferably, the orientation of the lifting head relative to the support post can be varied.

In one version of the invention, the support post axis intersects the pivoting axis so as to define an in-line pivoting arrangement.

In an alternative version, the support post axis does not intersect the pivoting axis, thereby defining an off-centre pivoting arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows an exploded perspective view of a jack according to a first embodiment of the invention;

Figure 2 shows a cross-sectional side view of the jack shown in Figure 1 located in position under the axle of a vehicle, ready for use;

Figure 3 shows a cross-sectional side view of the jack shown in Figure 1 in a raised position, in which the axle of the vehicle has been lifted;

Figure 4 shows a perspective view of a jack according to a second embodiment of the invention; Figure 5 shows a side view of the jack shown in Figure 4, ready for use;

Figure 6 shows a top view of a jack according to a third embodiment of the invention;

Figure 7 shows a side view of the jack shown in Figure 6;

Figure 8 shows a side view of a lifting head for use with the jack shown in

Figures 6 and 7;

Figure 9 shows a front view of the lifting head shown in Figure 8; and

Figures 10, 11 and 12 show side views of a jack according to a fourth embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

Referring to Figures 1 to 3, a jack 10 comprises a lifting head or cradle 12 for supporting a vehicle's axle 14. The lifting head 12 includes a substantially flat platform 16 and a pair of upwardly extending arms 18 and 20 for snugly accommodating the axle 14. The lifting head 12 is fitted with a rubber lining 22 for protecting and padding the axle 14 as well as the lifting head 12.

A round cylindrical tubular connecting element 24 is welded to the bottom surface of the platform 16, and is used to connect the lifting head 12 to a pivot arm assembly 26 via connecting pin 28. The connecting pin 28 is arranged to slide through two pairs of apertures 30 and 32 defined in the connecting element 24 and the pivot arm assembly 26 respectively. The pivot arm assembly 26 comprises a pair of interconnecting tubular portions 34 and 36. The portions 34 and 36 are connected together by means of a connecting pin 38 that extends through apertures 40 and 42 defined in the tubular portions 34 and 36. Although in Figure 1 only one aperture 42 is shown in the tubular portion 36, it is clear that any number of apertures can be defined for allowing the overall height of the pivot arm assembly 26 to vary. Advantageously, this feature allows the jack 10 to be used on vehicles having varying heights.

The pivot arm assembly 26 is pivotally mounted to a pedestal arrangement 44 comprising a base or foot plate 46 and a U-shaped housing 48 welded thereto. The housing 48 includes a pair of side walls or arms 50 and 52, each arm defining a slot 54 and 56 respectively for receiving a pivot pin 58, which extends through a pair of lower apertures 60 defined in the tubular portion 36, and which is arranged to be supported within the slots 54 and 56.

A rear wall or barrier 62 extends between the arms 50 and 52 against which the pivot arm assembly 26, and in particular, the tubular portion 36 abuts, when the pivot arm assembly 26 is in a raised, engaged position, as shown in Figure 3. Significantly, the pivot arm assembly 26 is arranged so that when it pivots to its raised, engaged position, the assembly 26 traverses an angle greater than 90°, and typically approximately 105°, so that in its raised, engaged position, the assembly 26 is locked in an over centre configuration, as shown in Figure 3. Advantageously, and with a view to fully and snugly supporting the assembly 26 in this position, the barrier 62 defines an angle between itself and the base plate of between 80° and 90°, and preferably an angle of 85°. The angled barrier 62 can be clearly seen in Figures 2 and 3.

The pivot arm assembly 26 defines a support post axis 63A, and the pivot pin 58 defines a pivoting axis 63B, the axes 63A and 63B being substantially normal to each other. In this embodiment of the invention, the axes 63A and 63B intersect each other so as to define an in-line pivoting arrangement.

A locking pin 64 is provided for locking the pivot arm assembly 26 in its raised position, as shown in Figure 3. The pin 64 extends through a pair of apertures 66 and 68 defined in the arms 50 and 52 respectively and through aligned locking apertures 70 defined in the tubular portion 36 for locking the pivot arm assembly 26 in its locked position.

In use, and with specific reference to Figures 2 and 3, the jack 10 is placed proximate the vehicle's axle 14 that is to be lifted. The pivot arm assembly 26 is mounted in position within the housing 48 and the lifting head 12 is fitted to the end of the lifting arm assembly 26, with the platform 16 engaging the axle 14. The vehicle is then driven or moved over the jack 10 in the direction of arrow 72. As the vehicle is being driven or moved, the head 12 engages and lifts the axle 14. The vehicle is driven until the pivot arm assembly 26 is in its raised, locked position, shown in Figure 3.

Thus, the pivot arm assembly 26 is movable from a lower, inoperative position to a raised, engaged position, in which the axle 14 and hence the vehicle is raised, by means of the vehicle itself driving or being moved over the jack 10 and with the axle 14 being lifted by the head 12. The base plate 46 is fitted with a piece of rubber material 74 for preventing the base plate 46 from slipping as the vehicle is mounting the jack 10.

Figures 4 and 5 illustrate a second embodiment of a jack 76 according to the invention, wherein a pivot arm assembly 78 is mounted to a U-shaped housing 80 by means of a trunnion assembly. In particular, the housing 80 comprises two pairs of axle receiving blocks 82 and 84, and 86 and 88 (not shown) for pivotally capturing a pair of stub axles that extend from either side of the pivot arm assembly 78. The pivot arm assembly 78 defines a support post axis 89A, and the stub axles that extend from either side of the pivot arm assembly 78 define a pivoting axis 89B. As with the embodiment illustrated in Figures 1 to 3, the axes 89A and 89B are substantially normal to each other and intersect each other so as to define an in-line pivoting arrangement.

Although the housing 80 is secured to a base plate 90 that is fitted with a piece of rubber material 92 for preventing the jack 76 from slipping as the vehicle 94 is mounting the jack 76, on certain terrain it has been found that the rubber material 92 is not sufficient to prevent the jack 76 from slipping. To address this problem, a U-shaped connector 94 is welded to the base plate 90 to which a chain 96, which defines a tread upon which the wheels of the vehicle may drive, is fitted. Thus, as the vehicle 94 approaches the jack 76, the wheels 98 of the axle that is not being lifted anchors the chain 96 and thus the jack 76 in position, so as to allow the axle that is to be lifted to firmly engage and be lifted by the jack 76 as described above. Although the tread has been described with reference to a chain, a belt, cable or rope could also be used.

Advantageously, the rear wall 100 of the housing 80 defines an angle between itself and the base plate 90 of approximately 85°, thereby, as described above, allowing the pivot arm assembly 78 to be locked in an over centre configuration.

Figures 6, 7, 8 and 9, illustrate a third embodiment of the jack 102 of the present invention. A pivot arm support post 104 is pivotally mounted to a pedestal arrangement 106 comprising a base plate 108 and a pair of support arms 110 and 112 welded thereto. A pivot axle extends between the support arms 110 and 112 for pivotally receiving a cylindrical sleeve 114 that is welded to a bottom edge of the support post 104, so as to define an off-centre pivoting arrangement. In particular, the off-centre pivoting arrangement comprises a support post axis 115A, defined by the support post 104, and a pivoting axis 115B, defined by a combination of the pivot axle and the sleeve 114, with the axes 115A and 115B being substantially normal to each other but arranged to not intersect each other.

A stop plate 116 is welded to the support post 104, so as to pivot with the support post 104. The stop plate 116 is shaped so that in the raised, engaged position shown in Figure 7, the support post 104 lies in an over centre configuration. In particular, the support post 104 defines an angle between itself and the base plate 108 of between 80° and 90°, and preferably an angle of 85°.

A combination of the off-centre pivoting arrangement and the over centre configuration defined by the shape of the stop plate 116 ensures that the support post 104 is essentially locked when it is in its raised, engaged position, thereby preventing the support post 104 from accidentally and/or easily pivoting away from the raised, engaged position.

To further ensure that the support post 104 remains in its raised, engaged position, a pair of apertured ears 118 and 120 is provided for receiving the stop plate 116 therebetween. The apertures of the ears 118 and 120 are in line with an aperture in the stop plate 116, so that a locking pin may be inserted therethrough so as to lock the stop plate 116 in position.

A U-shaped connector 122 is welded to the pair of support arms 110 and 112 for receiving a tread chain, the purpose of which has been described above.

The support post 104 receives a lifting head 124, which is shown in further detail in Figures 8 and 9. The lifting head 124 includes a substantially flat platform 126 and a pair of upwardly extending arms 128 and 130 for snugly accommodating the axle of a vehicle. A round cylindrical tubular connecting element 132 is welded to the bottom surface of the platform 126, and is used to connect the lifting head 124 to the pivot arm support post 104 via a connecting pin, as described above. The connecting pin is arranged to slide through two pairs of apertures defined in the connecting element 132 (not shown) and the pivot arm support post 104 respectively.

Significantly, the orientation of the pairs of apertures, for example 134A and 134B, in the pivot arm support post 104 with respect to subjacent and/or superjacent pairs of apertures, for example 136A and 136B, and 138A and 138B, respectively, vary. This advantageously allows the orientation of the lifting head 124 to be varied relative to the support post 104. A further advantage of this arrangement is that it results in a stronger structure in that there is more material between adjacent, vertically spaced pairs of apertures.

In certain situations, however, it is envisaged that it will not be possible to lock the support post in its over centre raised, engaged position as described above. To address this, an angle locating chain 140 is mounted to the base plate 108, which can be fitted to a locating element 142 secured to the stop plate 116, thereby allowing the support post 104, and thus the connecting element, to be locked in an intermediate position.

Conveniently, the stop plate can be fitted with a bar for allowing the jack to be operated manually.

Figures 10, 11 and 12 show side views of yet a further embodiment of a jack according to the present invention. The jack 144 comprises a pivot arm assembly including a support post 146 and a terminal post 147 that is mounted to the support post 146 in such a way that that the terminal post 147 is able to rotate or swivel relative to the support post 146. To achieve this rotating feature, the terminal post 147 can be fitted to the support post 146 in any one of a number different ways. In the preferred version, the terminal post 147 has a tubular base portion having a slightly smaller diameter than the diameter of the support post 146, for allowing the terminal post 147 to be snugly accommodated within the support post 146.

The support post 146 is pivotally mounted to a base plate 148 by means of a cylindrical sleeve 150 attached to the bottom of the support post 146. The sleeve 150 is in turn arranged to rotate around an axle that extends between a pair of support arms, as described in detail earlier in the specification with reference to Figures 6 and 7. The pivot arm assembly is thus arranged to move from a lowered position, shown in Figure 10, in which a vehicle's axle 152 has just been engaged, to a raised, engaged position, shown in Figure 11 , in which the axle 152 and hence the vehicle is raised.

In particular, in the raised, engaged position, the support post 146 lies in an over centre configuration, with the post 146 defining an angle θ between itself and the base plate 148. The angle θ is typically between 80° and 90°, and preferably 85°. Alternatively, or in addition, a stop plate, such as the plate 116 illustrated in Figure 7, could be welded to the post 146 so as to define this over centre configuration.

Significantly, the terminal post 147 is fitted with a hinge cup 154 for accommodating the vehicle's axle 152. The hinge cup 154 comprises a gusset 156 that is pivotally mounted to the post 146. This could be achieved by using any one of a number of conventional arrangements, such as by means of a hinge pin 157 that extends through the gusset 156 and which then locates within a cylindrical sleeve mounted to the terminal post 147. A pair of arms 158 and 160 is fitted to the gusset 156 for receiving the axle 152. A lip 162 extends from the arm 158 for securely holding the axle 152 in position within the hinge cup 154. The pivoting hinge cup 154 has a number of advantages, the primary one of which is shown more clearly in Figure 12. By rotating the terminal post 147 through 180°, in the direction indicated by arrow 164, a vehicle having a relatively lower axle 152 can now be engaged and lifted by the jack 144. A further advantage of this version of the invention is that as the vehicle is being lifted there is no movement of the axle 152 relative to the hinge cup 154. Thus, no friction is caused by these components on each other as the vehicle is being lifted, thereby greatly reducing the wear on these components.

The jack is constructed from high tensile steel and is thus able to lift a vehicle having a mass of up to 30 tons. Although the primary application of the present invention is to lift trailers, it can just as easily be used to lift motor vehicles that can be driven with at least one half of an axle raised. A significant advantage of the present invention is that it saves a substantial amount of time when it comes to lifting vehicles, when compared to traditional jacks.

Claims

1. A jack for lifting an axle of a vehicle, the jack comprising:

a lifting head for engaging the axle;

a support post extending from the lifting head;

a base assembly; and

2. A jack according to claim 1 wherein the base assembly includes a base plate and a housing fitted to the base plate, the housing accommodating the support post and including the pivoting mounting means.

3. A jack according to claim 2 wherein the housing includes a rear wall and a pair of side walls, each side wall defining a slot for receiving a pivot pin, which extends through a pair of lower apertures defined in the support post, the combination of the slots and the pivot pin defining the pivoting mounting means.

4. A jack according to claim 2 wherein the housing includes a rear wall and a pair of side walls, with a pair of axle receiving blocks being fitted adjacent each side wall for pivotally capturing a pair of stub axles that extend from either side of the support post, the combination of the axle receiving blocks and stub axles defining the pivoting mounting means.

5. A jack according to either one of the preceding claims 3 or 4 wherein the rear wall of the housing defines stop means, against which the support post, in the operative, raised position abuts so as to define an over centre configuration.

6. A jack according to claim 5 wherein the over centre configuration is defined by the rear wall, which defines an angle between itself and the base plate of approximately 85°.

7. A jack according to claim 2 wherein the housing includes a pair of spaced apart support arms, with a pivot axle extending between the support arms for pivotally receiving a sleeve that is fitted to the support post, the combination of the pivot axle and sleeve defining the pivoting mounting means.

8. A jack according to claim 7, which includes a stop plate that extends from, and is pivotable with, the support post, the stop plate being shaped so as to define stop means, so that in the raised, engaged position the stop plate and thus the support post abuts against the base plate in an over centre configuration.

9. A jack according to any one of the preceding claims wherein at least one intermediate connecting element extends between the lifting head and the support post and/or between the support post and the base assembly for allowing the overall height of the jack to be varied.

10. A jack according to any one of the preceding claims, which includes at least one tread that is connectable to the base assembly, the tread extending from the base assembly so as to define a track upon which the wheels of the vehicle may drive, so that in use as the vehicle approaches the jack the wheels of the axle that is not being lifted anchors the tread and thus the jack in position, so as to allow the axle that is to be lifted to firmly engage and be lifted by the lifting head of the jack.

11. A jack according to any one of the preceding claims, wherein the lifting head includes a cup for accommodating the axle, the cup being pivotable relative to the support post.

12. A jack according to any one of the preceding claims wherein the lifting head includes a substantially flat platform and a pair of upwardly extending arms for snugly accommodating the axle.

13. A jack according to any one of the preceding claims, which includes locking means for locking the support post in its raised position.

14. A jack according to any one of the preceding claims wherein the orientation of the lifting head relative to the support post can be varied.

15. A jack according to any one of the preceding claims wherein the support post defines a support post axis, and the pivoting mounting means defines a pivoting axis, wherein the support post axis intersects the pivoting axis so as to define an in-line pivoting arrangement.

16. A jack according to any one of claims 1 to 14, wherein the support post defines a support post axis, and the pivoting mounting means defines a pivoting axis, wherein the support post axis does not intersect the pivoting axis, thereby defining an off-centre pivoting arrangement.