Technical Field

The present invention relates to a compact lift apparatus. The lift apparatus may be configured to be mobile in its assembled state, or to be deconstructed for ease of transport.

Background

Any discussion of the prior art throughout the specification is not an admission that such prior art is widely known or forms part of the common general knowledge in the field.

One application in which it can be desirable to elevate a load from a first, lower position to a second, higher position, is workers wanting access to a part of a building that is too high to reach. Alternatively, the load can be freight, rather than people.

US 3,516,512 discloses a mobile scaffold provided with stabilising arms which could be connected to the carriage either in an elongated position, or in a concealed retracted position. In order to move the arms between positions, each arm has to be removed from the carriage by undoing the connecting bolt, flipped over, and then bolted back on. The arms can be fitted with wheels or castors to allow the unit to be transported without necessitating dismantling.

Application US 20080128215 discloses a lift apparatus generally comprising a base unit, wheels rotatably mounted to the base unit, a handle fastened to the base, a scissor lift mounted to the upwardly facing surface of the base unit, and a horizontally extending platform mounted to the upper ends of the lift; the platform being selectively movable along a vertical axis by actuation of the lift by the user. There is no disclosure of dismantling the apparatus for transport.

In another known type of lift, a scissor lift mechanism is mounted at a lower end on a chassis, a work platform mounted on an upper end of the lift mechanism for carrying persons, and an actuation system operates the lift mechanism to raise and lower the work platform. The scissor lift mechanism includes a plurality of pairs of arms pivotally interconnected in a scissor-like fashion so as to raise and lower as the arms pivot between generally vertical unstacked and horizontal stacked orientations relative to one another. In order to provide stability, the chassis may be provided with at least 300 kg of weighted ballast.

In an attempt to reduce the weight of ballast provided, some lifts have been provided with stabilising outriggers which rotate into position. The unit cannot be used while the outriggers are rotating into position. It is an object of the present invention to provide a compact lift apparatus that weighs less than the prior art units, or can be dismantled into lighter sub-units, or to provide the public with a useful choice.

Disclosure of Invention

Therefore the present invention provides a base for a lift, said base including:

a frame; and

at least one stabiliser moveable between a first stabiliser position in which it is substantially enclosed within the frame and a second stabiliser position in which it extends beyond the frame.

Preferably the or each stabiliser moves between the first stabiliser position and the second stabiliser position by sliding. In a preferred embodiment at least one of one stabiliser and the frame is fitted with a guide, and the other of the stabiliser and the frame is fitted with engagement means for engaging with, and sliding along the guide. More preferably, the or each stabiliser is fitted with at least one guide for engaging with an engagement means on the frame; and at least one engagement means for engaging a guide on the frame. More preferably yet, the or each stabiliser includes one guide and one engagement means on each of two opposite sides of the stabiliser.

Preferably the or each stabiliser is moveable from the second stabiliser position to a third stabiliser position, in which an end of the stabiliser furthest from the frame is lower than an opposite end of the stabiliser closest to the frame.

In a preferred embodiment, the or each stabiliser is made from a material selected from the list consisting of: steel, aluminium, titanium, composite materials, plastics, alloys, or combinations thereof. Preferably the or each stabiliser may include holes to reduce its weight.

In a preferred embodiment, there are two stabilisers. More preferably, the two stabilisers may be on opposite sides of the frame. More preferably still, the two stabilisers may be interlocked, so as to move substantially as mirror images of each other.

In a preferred embodiment, the frame is about 700 mm in width, and the or each stabiliser in the second position extends about 150 mm beyond the frame.

In a preferred embodiment, the base is a chassis. More preferably, the chassis includes wheels or castors and a drive mechanism.

The present invention further provides a locking mechanism, including:

at least one pin; a rotatable engagement lever; and

transforming means for transforming rotation of the engagement lever into sliding movement of the or each pin.

In a preferred embodiment, the transforming means includes at least one actuation arm rotatably connected at a first end to a pin and at a second end, distal to the first end, rotatably connected to the engagement lever. Preferably the or each actuation arm also includes a guide engagement means slidingly engaged with a fixed guide, to provide a sliding pivot for the actuation arm.

Preferably the locking mechanism includes two pins.

The present invention further provides a lift including:

a base;

a work platform; and

a lift mechanism between the base and the work platform, adapted to move the work platform between a first platform position and a second platform position, the second platform position being vertically displaced from the first platform position.

In a preferred embodiment, the base is as described above. Preferably the or each stabiliser is coupled with the lift mechanism so that the or each stabiliser automatically moves from the first stabiliser position towards the second stabiliser position (and/or optionally third stabiliser position) as the work platform moves from the first platform position towards the second platform position. More preferably if the or each stabiliser is prevented from moving, the lift mechanism is automatically prevented from moving the work platform any higher.

Preferably the base is removably connected to a first end of the lift mechanism by means of at least one locking mechanism described above. Alternatively the work platform is removably connected to a second end of the lift mechanism distal to the first end by means of at least one locking mechanism described above. In another alternative, both the base is removably connected to a first end of the lift mechanism by means of at least one locking mechanism described above; and the work platform is removably connected to a second end of the lift mechanism distal to the first end by means of at least one locking mechanism described above.

In a preferred embodiment, the or each locking mechanism is interlocked with the lift mechanism so that the lift mechanism will not operate if a locking mechanism connecting any two parts of the lift is not correctly engaged. The work platform may be adapted for a purpose selected from the list consisting of: holding people, holding freight, and holding part of a roller door.

Brief Description of the Drawings

By way of non-limiting example only, preferred embodiments of the invention are described in detail below with reference to the accompanying drawings, in which:

Figure 1 is an inverted perspective view of parts of a chassis for a lift according to the present invention;

Figure 2 is a side view of the chassis of Figure 1 in a retracted configuration;

Figure 2A is a cross-section view of the chassis of Figure 2 along line A-A;

Figure 2B is a cross-section view of the chassis of Figure 2 along line B-B;

Figure 3 is a side view of the chassis of Figure 1 in an extended configuration;

Figure 3 A is a cross-section view of the chassis of Figure 3 along line A-A;

Figure 3B is a cross-section view of the chassis of Figure 3 along line B-B;

Figure 4 is a side view of the chassis of Figure 1 in a travel configuration;

Figure 4A is a cross-section view of the chassis of Figure 4 along line A-A;

Figure 4B is a cross-section view of the chassis of Figure 4 along line B-B;

Figure 5 is a plan view of a lock mechanism according to the present invention in a closed position;

Figure 6 is a perspective view of the lock mechanism shown in Figure 5 in a closed position;

Figure 7 is a plan view of the lock mechanism shown in Figure 5 in an open position;

Figure 8 is a perspective view of the lock mechanism shown in Figure 5 in an open position;

Figure 9 is a perspective view of a compact lift according to the present invention in a lowered position; and

Figure 10 is a perspective view of a compact lift according to the present invention in a raised position.

Best Method of Performing the Invention

A preferred embodiment of a compact lift according to the present invention includes a chassis, and elevation system, and a work platform.

Figure 1 shows a part of the chassis 101 of the compact lift. The main chassis body 102 includes a frame 130 including wheel spaces 103 for receiving wheels or castors, a drive system (not shown) for at least one of the wheels, power storage for the drive system (not shown), a first stabiliser 111 and a second stabiliser 112, a stabiliser coupler 113, primary first engagement means 114, secondary first stabiliser guide 115, primary second engagement means 116, secondary second stabiliser guide 117, and a stabiliser actuator (not shown).

Main chassis body 102 and first stabiliser 111 and second stabiliser 112 are constructed from known materials selected for providing the appropriate strength and lightness, such as steel, aluminium, titanium, composite materials, plastics, alloys or combinations thereof. Cut-outs may be included to reduce the total weight; by way of example in Figure 1 holes 118 are shown in first stabiliser 111 and second stabiliser 112. Preferably the total weight of the chassis 101 is 50 kg or less.

First stabiliser 111 is shown including holes 118 and having feet 119 made of an appropriate known material such as ultra-high-molecular-weight polyethylene (UHMWPE).

First stabiliser 111 (shown in Figures 1 to 4) includes a first stabiliser body 161 and two engagement sidewalls 162 extending substantially parallel to each other from opposite sides of first stabiliser body 161. Each first engagement sidewall 162 includes a primary first engagement guide 163 and a secondary first engagement means 164. Secondary first engagement means 164 are adapted to engage with a secondary first stabiliser guide 115 in the frame 130.

Second stabiliser 112 (shown in Figures 1 to 4) is a mirror image of first stabiliser 111. Second stabiliser 112 includes a second stabiliser body 171 and two engagement sidewalls 172 extending substantially parallel to each other from opposite sides of second stabiliser body 171. Each second engagement sidewall 172 includes primary second engagement guide 173 and a secondary second engagement means 174. Secondary second engagement means 174 are adapted to engage with a secondary second stabiliser guide 117 in the frame 130.

Primary first engagement guide 163 engages with the frame 130 so primary first engagement means 114 can slide along primary first engagement guide 163; primary second engagement guide 173 engages with the frame 130 so primary second engagement means 116 can slide along primary secondary engagement guide 173. Primary first engagement guide 163 includes a primary guide ramp section 165 and a primary guide drop section 166. Primary second engagement guide 173 is a mirror image of primary first engagement guide 163.

Secondary first engagement means 164 engages with the frame 130 so secondary first engagement means 164 can slide along secondary first stabiliser guide 115, and secondary second engagement means 174 engages with the frame 130 so secondary second engagement means 174 can slide along secondary second stabiliser guide 117. Secondary first stabiliser guide 115 includes a secondary guide slide section 133 and a secondary guide rest section 134. Secondary second stabiliser guide 117 is a mirror image of secondary first stabiliser guide 115.

Figures 2, 2A, and 2B show the stabilisers in a retracted (first) position. In this position, primary first engagement means 114 engages primary first engagement guide 163 at an end of primary guide drop section 166 distal to primary guide ramp section 165, and primary second engagement means 116 is at a corresponding end of primary second engagement guide 173. Secondary first engagement means 164 is engaged with secondary first stabiliser guide 115 at the end of secondary guide slide section 133 distal to secondary guide rest section 134, and secondary second engagement means 174 is engaged with secondary second stabiliser guide 117 at a corresponding position.

Figures 3, 3A, and 3B show the stabilisers in an extended (third) position. In this position, primary first engagement means 114 engages with primary first engagement guide 163 at the end of primary guide ramp section 165 distal to primary guide drop section 116, and primary second engagement means 116 is at a corresponding end of primary second engagement guide 173. Secondary first engagement means 164 is engaged with secondary first stabiliser guide 115 at secondary guide rest section 134, and secondary second engagement means 174 is engaged with secondary second stabiliser guide 117 at a corresponding position.

Figures 4, 4A, and 4B show the stabilisers in an intermediate (second) travel position. In this position, secondary first engagement means 164 is engaged with secondary first stabiliser guide 115 at the end of secondary guide slide section 133 adjacent secondary guide rest section 134, and secondary second engagement means 174 is engaged with secondary second stabiliser guide 117 at a corresponding position.

As shown in Figures 2 to 4, the positions of first stabiliser 111 and second stabiliser 112 are mirror images of each other. This is achieved by stabiliser coupler 113, which transfers linear displacement of first stabiliser 111 along secondary first stabiliser guide 115 into an opposite linear displacement of second stabiliser 112 along secondary second stabiliser guide 117. In this preferred embodiment, stabiliser coupler 113 is a simple scissor connector.

A standard linear actuator may be coupled to first stabiliser 111 to move the stabilisers between the positions shown in Figures 2 to 4. In the retracted position shown in Figure 2, the stabilisers are almost completely within frame 130. As first stabiliser 111 is pushed towards the extended position shown in Figure 3, secondary first engagement means 164 slides along secondary guide slide section 133 as stabiliser 111 extends beyond frame 130. Preferably stabiliser 111 may reach a full extension of approximately 150 mm beyond frame 130. When secondary first engagement means 164 reaches the end of secondary guide slide section 133, it rises to enter secondary guide rest section 134. This rotates stabiliser 111 about primary first engagement means 114, so that feet 119 lower to be close to the surface on which the wheels of chassis 101 are resting.

It will be appreciated that although the movement is described with reference to first stabiliser 111, because of the mirror image configuration, and the action of the stabiliser coupler 113, second stabiliser 112 will move in a corresponding fashion.

Retracting stabiliser 111 slightly disengages secondary first engagement means 164 from the secondary guide rest section 134, to reach the position shown in Figure 4. Stabiliser 111 rotates about primary first engagement means 114 so that feet 119 are lifted away from the surface. Preferably they are lifted about 10 mm, so that in this travel position, chassis 101 can travel a short distance without feet 119 causing friction, but with stabilisers 111 and 112 extended to improve stability of the lift.

In a highly preferred form, the actuator for first stabiliser 111 is coupled with the elevation system so that the stabilisers are automatically extended when the work platform is raised. Preferably the stabilisers may reach the extended position by the time the work platform has been elevated by 1 metre. Conversely, coupling may provide that if the stabilisers are unable to fully extend, the elevation system does not allow the work platform to be raised higher.

In this preferred embodiment, chassis 101 is also provided with a lock mechanism 201 for releasably engaging chassis 101 with the elevation system.

As shown in Figures 5 to 8, lock mechanism 201 on the chassis provides a first pin 210 slidingly engaged with a first pin guide 212, which is fixed in position on the chassis. First pin 210 is rotatably connected via first pin connector 224 with a first pin actuating arm 214. First pin actuating arm 214 includes a first actuating arm guide engager 218 slidingly engaged with a first actuating arm guide 216, which is fixed in position on the chassis. An end of first pin actuating arm 214, distal from first pin connector 224, is rotatably coupled, via first actuator arm connector 222, with a first end of bolt engagement lever 220. Bolt engagement lever 220 is rotatably engaged with central pivot 221, which is fixed in position on the chassis. Bolt engagement lever 220 is provided with a handle 226, which allows it to be rotated about central pivot 221 between the "closed" position shown in Figures 5 & 6, and the "open" position shown in Figures 7 & 8.

A second end of bolt engagement lever 220, distal to the first end, is rotatably connected to a second pin actuating arm 215 via second actuation arm connector 223. Second pin actuating arm 215 includes second actuating arm guide engager 219, which is slidingly engaged with a second actuating arm guide 217, which is fixed in position on the chassis. At an end distal to second actuation arm connector 223, second actuation arm 215 is rotatably connected to second pin 211 via a second pin connector 225. Second pin 211 is slidingly engaged with a second pin guide 213, which is fixed in position on the chassis.

The lift mechanism (schematically indicated in outline) is provided with a first pin engager 231 and a second pin engager 232, dimensioned and spaced so as to receive respectively the first pin 210 and the second pin 211 when the lock mechanism 201 is in the closed position shown in Figures 5 and 6. Each pair of pin engager and pin may be alternatively be configured for a complementary engagement, for example by the pin engager included a tapered cavity to receive a tapered end of the pin in a mating engagement.

When in the closed position shown in Figures 5 and 6, the lock mechanism 201 locks together the chassis and the lift mechanism. It will be appreciated by one skilled in the art that more than one lock mechanism 201 may be provided between the chassis and the lift mechanism. Furthermore, one or more corresponding lock mechanisms may be provided on the work platform to removably lock it to the top of the lift mechanism.

The lock mechanism 201 allows the chassis to be decoupled from the lift mechanism. In order to achieve this, handle 226 is rotated from the "closed" position shown in Figures 5 and 6 to the "open" position shown in Figures 7 and 8. A safety pin 227 locks bolt engagement lever 220 into the closed position, and must be released to allow rotation to occur. In a preferred embodiment, safety pin 227 is spring loaded. Rotation of the handle 226 rotates the bolt engagement lever 220 about central pivot 221. The angular movement of the bolt engagement lever 220 is translated by first pin actuation arm 204 (by rotation about first actuation arm connector 222, sliding along the first actuating arm guide 216, and rotation about first pin connector 224) into sliding of first pin 210 through first pin guide 212 until it has disengaged with first pin engager 231. Correspondingly, the angular movement of bolt engagement lever 220 is translated by second pin actuation arm 215 (by rotation about second actuation arm connector 223, sliding along the second actuating arm guide 217, and rotation about second pin connector 225) into sliding of second pin 211 through second pin guide 213 until it has disengaged with second pin engager 232.

Once the or each locking mechanism 201 has been switched to the "open" configuration, the lift mechanism can be lifted off the chassis for separate transportation or storage. The lift mechanism and/or the chassis may be fitted, permanently or removably, with handles to facilitate this removal. Preferably the safety pin 227 re-engages when the open configuration is reached, to prevent rotation of the bolt engagement lever 220 during transport.

As a safety feature, the lock mechanism 201 can be interlocked with the activation system of the lift mechanism, and/or the drive system of the chassis, so that the lift cannot be used unless the sections are securely connected. This may be achieved by the inclusion of an activation sensor (not shown) in first actuating arm guide 216 at the point reached by first actuating arm guide engager 218 in the fully closed position shown in Figure 5. When first actuating arm guide 216 reaches this position, the first pin 210 is fully engaged with first pin engager 231, and the lift components are securely held together by the lock mechanism.

Figures 9 and 10 show the assembled lift, including chassis 101, lift mechanism 301 and work platform 302. In Figure 9, lift mechanism 301 is fully compressed, so that work platform 302 is in a lowered position. First stabiliser 111 and second stabiliser 112 are substantially enclosed within the frame 130 of chassis 101, as described in detail with reference to, and shown in, Figure 2. In Figure 10, lift mechanism 301 is fully extended, so that work platform 302 is in a raised position. First stabiliser 111 and second stabiliser 112 are fully extended and lowered, as described in detail with reference to, and as shown in, Figure 3.

Work platform 302 is shown as a cage suitable for holding at least one person. Such a cage may be collapsible for ease of transport. However, work platform 302 can be any work platform suitable for the desired task, including a flat work platform for people, a platform for freight, or a customised platform for a specific application, such as the lifting of one section of a roller door. The chassis and lift mechanism can be provided with a selection of interchangeable work platforms. Through the use of the locking mechanism of the present invention, the appropriate work mechanism for each job can be locked into place, then removed and replaced before the next job. To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting. This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements and features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

List of Reference Numerals

101 chassis

102 chassis body

103 wheel spaces

111 first stabiliser

112 second stabiliser

113 stabiliser coupler

114 primary first engagement means

115 secondary first stabiliser guide

116 primary second engagement means

117 secondary second stabiliser guide

118 holes

119 feet

130 frame

133 secondary guide slide section

134 secondary guide rest section

161 first stabiliser body

162 first engagement sidewall

163 primary first engagement guide

164 secondary first engagement means

165 primary guide ramp section

166 primary guide drop section

171 second stabiliser body

172 second engagement sidewall

173 primary second engagement guide

174 secondary second engagement means

201 lock mechanism

210 first pin

211 second pin

212 first pin guide

213 second pin guide

214 first pin actuating arm

215 second pin actuation arm

216 first actuating arm guide 217 second actuating arm guide

218 first actuating arm guide engager

219 second actuating arm guide engager

220 bolt engagement lever

221 central pivot

222 first actuating arm connector

223 second actuating arm connector

224 first pin connector

225 second pin connector

226 handle

227 safety pin

231 first pin engager

232 second pin engager