Vehicles and vehicle lifts

Abstract: A vehicle lift for stowing beneath the floor of a vehicle includes rails (83, 84) in which can move structure (11). A platform (27) is pivoted to the outer pivots (23a, 24a) of two parallelogram arrangements (20) whose inner pivots (23, 24) are with structure (11). A ram (34) is pivoted between the structure (11) and structure including plates (30, 31) pivoted at (32, 33) on axis (34) to the structure (11). The pivots (32, 33) are coaxial with pivots (23) and the ram is pivoted to plates (30, 31) at a location spaced from axis (34). The platform can be raised and lowered when the lift is not stowed. Arrangements are described in which the lift is stowed in an inclined position; in which the platform can form a step; in which the parallelograms are modified to alter the inclination of the platform.

Description: THIS INVENTION relates to vehicles and vehicle lifts, according to the characteristics of the preambles of independent claims 1 and 10. US-A-3498481 shows a lift for a truck which comprises an inner mounting structure and an outer lift platform, the outer lift platform being deployable for operation between a raised position and a lowered position by means comprising a parallelogram arrangement, said parallelogram arrangement having a first upper side element and a second lower side element, said first and second side elements having an inner pivotal connection with said platform, said parallelogram arrangement being modified such that said inner pivotal connection and outer pivotal connection define unequal spacing therebetween. This provides for the platform to be upwardly inclined towards its outer end in the raised position and downwardly inclined towards its outer end in the lowered position. DE-A-3531853 is considered to disclose the closest prior art and discloses a vehicle lift having a platform slidably movable between inner and outer positions with respect to the vehicle and capable also of being raised and lowered on pivotal elements with respect of the vehicle. However, the platform consists of inner and outer pivotally connected parts which are folded in superimposed relationship in an inner stowed position and must be unfolded before the platform can be raised or lowered. This arrangement requires a complex and expensive structure from the point of view of manufacture and maintenance. Also strength and rigidity are reduced when compared to a single rigid platform, and there may be a tendency for small undesirable movements between the inner and outer platform parts when under load. Other devices are known in which a manoeuvrable platform includes means acting as a roll stop to prevent articles from rolling off the platform when it is raised above the ground. Such means are not disclosed in the aforementioned documents. According to the present invention there is provided a vehicle lift mounted to a vehicle for transporting a person having limited mobility comprising an inner mounting structure and an outer lift platform, the inner mounting structure being coupled to an outer support structure, the platform being deployable for operation between a raised position and a lowered position by means comprising a parallelogram arrangement having first upper side elements and second lower side elements, said first upper side elements and said second lower side elements having inner pivotal connections with said inner mounting structure, and a pivotal part hingedly attached to said platform and acting as a roll stop movable between an upright safety position and a lowered deployment position; characterised in that said outer support structure is comprised of elongated members attached to the vehicle wherein the inner mounting structure is movable in a horizontal sliding movement within said outer support structure between an inner position and an outer position and the movement of the pivotal part being activated by engagement of at least one ground engaging means with the ground surface. Further according to the present invention there is provided a vehicle lift mounted to a vehicle for transporting a person having limited mobility comprising an inner mounting structure and an outer lift platform, the inner mounting structure being coupled to an outer support structure, the platform being deployable for operation between a raised position and a lowered position by means comprising a parallelogram arrangement having first upper side elements and second lower side elements, said first upper side elements and said second lower side elements having inner pivotal connections with said inner mounting structure, and a pivotal part hingedly attached to said platform and acting as a roll stop movable between an upright safety position and a lowered deployment position; characterised in that the outer support structure is comprised of elongated members attached to the vehicle wherein the inner mounting structure is movable in a horizontal sliding movement in said elongated members and said parallelogram arrangement is modified to define an unequal parallelogram whereby to carry the platform so as to change the inclination of the platform as it moves between the upper and lower positions and whereby the platform moves in a substantially horizontally inclined movement during deployment of the platform. The invention may be performed in various ways and some specific embodiments with possible modifications will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a side view of a vehicle with lift; Fig. 2 is a perspective view of part of a lift; Fig. 3 is a perspective view of another part of the lift; Fig. 4 is a section through part of Fig. 3; Fig. 5 is a plan view of the lift; Fig. 6 is a rear view of another arrangement; Fig. 7 is similar to Fig. 3; Fig. 8 shows operation of the lift; Fig. 9 shows a modified platform; Figs. 10A, 10B show a modified lift; Fig. 11 shows a drive system; Fig. 12 is an enlarged view of part of Fig.10A; Fig. 13 shows operation of a lift; Fig. 14 shows a modification; Fig. 15 shows a rail arrangement; Figs.16, 16A show a modification; Fig. 17 shows a vehicle with rear lift; Fig. 18 is a side view of a platform ramp; Fig. 19 is an end view of part of Fig. 18; and Fig. 20 shows a platform. Referring to Figs. 1 to 5, a vehicle lift 10 comprises a mounting structure 11 comprising fabricated side members 12, 13 fixed to cross-members 14, 15 with bracing 16. Parallel plates 17, 18 are fixed to the cross members parallel to members 12, 13. A parallelogram arrangement 20 comprises two pairs of upper and lower side elements 21, 22 and 21a, 22a. The elements in each pair at one end are pivoted at 23, 24 between the sides of members 12, 13 with cut-out 25. At their other ends the elements 21, 22 are pivoted at 23a, 24a to the front of a rear part 26 of a flat platform 27 having a front part 28 which is pivoted to the front of the part 26 so as to be movable between an open position (Fig. 3) and a closed position (A in Fig. 1). The platform is shown open in full line in Fig. 1. The elements in each pair 21, 22 and 21a, 22a nest within each other at all times so that no gap exists between them as viewed sideways; this is a safety feature. Towards their rear ends the upper elements 21, 21a are connected by a cross-member 29 to which are fixed two arms 30, 31 respectively pivoted to plates 17, 18 at 32, 33 on a common transverse axis 34a which is in line with pivots 23. A hydraulic piston/cylinder ram 34 is located between plates 17, 18 and the piston 35 is pivoted at 36 to cross member 29 and the cylinder is pivoted at 37 to cross member 14. Pivot 36 is spaced from axis 34. When the ram 34 is energised and de-energised, the parallelogram arrangement 20 is pivoted up and down (see Fig. 1). In use, the platform is horizontal or inclined as described later. The mounting structure 11 is movable between side rails or supports 40, 41 between an outer or operative position (Fig. 2) and an inner or inoperative position, shown dotted at B in Fig. 1. Any suitable means may be used, but as shown, the outer faces 42 of members 12, 13 are provided with two or more spaced bosses 43 having upper and lower plastics pieces 44, 45 in sliding engagement with plastics liners 46, 47 on the confronting faces of the upper and lower arms of the rails 40, 41. Brackets 48 (only one shown) are respectively fixed to the members 12, 13 and are secured to respective chains 49 extending round sprockets 50, 51 secured to the rails 40, 41. A motor 52 e.g. electric, can rotate the sprockets 51 on a common axle to move the structure 11 in and out on the rails. It will be understood that because the elements 21, 22 and 21a, 22a are inwards of rails 40, 41 the ram 34 can be operated to raise or lower the platform at all positions of the structure in relation to the rails 40, 41. The lift 10 is intended primarily for use by the disabled and handicapped, in particular with wheelchairs, and for mounting beneath the floor 60 of a vehicle. Fig. 1 illustrates a mounting beneath the rear of a vehicle having a rear door, and rear bumper 61. If there is sufficient room beneath the vehicle the lift can be mounted with rails 40, 41 horizontal. However, it is often the case that the vehicle structure beneath the floor 60 would prevent this unless the lift structure undesirably enters into the space 62 beneath the minimum angle of departure 63 which normally extends upwards and rearwards from the point of contact between the rear wheels 64 and ground 65. Thus in the example of Fig. 1, brackets 70 are fixed to spaced fore-and-aft chassis members 71 of a monocoque body 72, and act as rear mounting for leaf springs 73. In the present lift, the rails 40, 41 can be mounted on the vehicle so as to be inclined upwards as they extend rearwards so that the inner ends C of the rails are below the springs 73 but the outer ends D are not beneath the angle of departure but are still beneath the bumper. The pivots 23, 24 and 23a, 24a are vertically spaced. The parallelogram is modified so that the separation between pivots 23, 24 is slightly (e.g. 2mm) less than the separation between pivots 23a, 24a so that in the down position the platform inclines slightly downwards as it extends outwards and in the top position the platform is inclined slightly upwards as it extends outwards. This is a safety feature. See also Fig. 13. The term parallelogram arrangement should be understood as including such an arrangement. In the withdrawn position the platform can be raised between the rails to be parked between the chassis members 71, subject to their spacing, and lightly held in contact with the body to resist rattle. The lift can be mounted to extend sideways and as shown in Fig. 6 the rails may in some cases incline downwards enabling the lift to be mounted in cases where the prop shaft 80 would effectively prevent horizontal mounting. Fig. 7 is generally similar to Figs. 2 and 3 but the motor 52 is central. Figs. 8 shows operation of a lift in association with a rear door of a vehicle. The platform may have a pivoted flap 76 to bridge any gap between the platform and the floor 76a of the vehicle. As shown in Fig. 9 the platform can be in two parts 110, 111 which are slidably cooperable. In this way the platform can be manually extended. The arrangement of Figs. 10A, 10B is similar to Figs. 2, 3 but, as shown, is intended for sale as a kit of parts and cross-members 81, 82 are fixed to rails 83, 84. The cross-members 81, 82 can be omitted if the rails are individually fitted to the vehicle. In this arrangement the rails 83, 84 have a vertical web 85, an inwardly directed horizontal arm 86 at the top of web 85 and a downwardly and inwardly inclined web 87 at the bottom of web 85. Spaced along the inner face of web 85 are spacers 88 to which is connected an elongate running rail 89. Each side of the structure 11 is provided with rollers 90, 91, engaging the upper and lower edges of rail 89, and rollers 92, rotating about vertical axes, engaging the inner face 93 of exposed rail 89. This arrangement resists accumulation of dirt as might interfere with proper operation, the dirt tending to wash or fall out of rails 83, 84. The structure 11 is moved in and out by motor 94 driving sprocket 95 engaging chain 96 which extends over sprockets 97 and is connected at its ends to cross members 81, 82 (see Fig. 11). As before the rails 83, 84 could be inclined. Releasable means may hold the structure 11 in a forward and rearward position. These means could be remote controlled, but as shown, the means comprise latches 100 engageable behind or in front of parts of structure 11 and connected to rods 101 which can be rotated, against the bias of springs 102, by handle 103 to move the latches from the path of structure 11, a transverse rotatable rod 104 connecting the latch mechanisms at the two sides. In another arrangement a manually releaseable sneck-type latch hook is mounted on the cross-members 81, 82 cooperable with latches on the front and rear of structure 11. The ram 34 is inclined downwards and pivots on bar 36 fixed to plates 30, 31 at a position spaced from and lower than axis 34a. The plates 30, 31 are fixed to cross member 29 which is fixed to upper parallelogram elements 21. A feature of Fig. 10a, which can be used in the other embodiments in which the platform slightly changes its orientation as it is moved up and down is that the lower arms 22, 22A of the parallelogram can be slightly reduced in length compared with upper arms 21, 21A. This controls (Fig. 13) the position at which the platform is horizontal as it moves between an incline slightly downwards as it extends outwards when in the lowered position and an incline slightly upwards as it extends outwards in the raised position. The term parallelogram arrangement should be understood as including this modification. In a modification Fig. 14 the sprockets 97 are positioned on top of structure 11 for rotation about vertical axes; this is for cases in which there is appropriate room beneath the vehicle, and provides an alternative drive means for the structure 11 which may enable the overall height of the lift 10 to be reduced. In an advantageous embodiment of Figs. 15, 16, 16A the platform has a pivoted part 112 which, in the raised and extended, or an intermediate and extended, position, can be folded inwards to form a step 113. The extent to which the platform is raised by the ram can be adjusted by changing the position of pivot 36. Fig. 17 shows a vehicle with rear door 113 and lift 10 having a platform 115 movable by, for example, a parallelogram lift device between lowered position on the ground and a raised position providing entry to the door. The door could be on the vehicle side. The lift may be stowable, for example beneath the vehicle floor, by a rotary action or sliding action. The platform has an inner part 76 which forms a stop and a bridge plate and an outer part 114, which forms a wheel-chair stop and a ramp. The part 114 automatically moves to a raised (wheel-chair stop) safety position when the platform is raised away from the ground, and automatically forms a ramp when the platform is in contact with the ground. The down ramp provides an upwardly inclined surface as it extends inwards. At the outer end of the main platform 115 is a cross-member 130 having at each end a shoe 131 adapted to engage the ground and biassed downwards by a spring 116. A pin 132 secured to link 133 has a lost motion connection in a slot 134 in an upstanding part 135 of the shoe. The link 133 is pivoted at 136 to a side wall 119 of the platform and has a pin 137 engageable with a tongue 138 on the part 114. When the platform is being lowered, the part 114 is in the dotted position. The shoes 131 engage the ground and are moved upwards relative to the platform 115 against the action of the springs 116 and the links 133 are moved from the dotted to the full line position, taking the links over-centre and the part 114 moves to the full line position under gravity. Upward movement of link 133 is limited by engagement of member 130 in a recess 140 in the structure. The link arrangement provides a mechanical advantage. The ramp part 114 moves under gravity and thus resists damage by engagement with a stone, and if accidentally engaging a user's foot, for example, will not damage the foot. On being raised from the ground, the springs 116 move over centre and move the shoes and links downwards and pivot the part 114 to the up, dotted, safety position. Downwards movement of the links is limited by engagement with stops 141. With ramp 114 up, this acts to resist movement of an article, e.g. a wheel-chair, off the platform away from the vehicle. A pivoted hand rail 150 is provided. As shown in Fig. 15, the rails 89 can be modified so as to have a horizontal outer portion 89a connected by a curved portion 89b to a straight, stowage, portion 89c parallel to supports 83, 84. In this way the structure 11, and the platform, are stowed in an inclined position but on being moved outwards they adopt a horizontal position. The lift may include electric control apparatus, including a hand-held switch box, and including limit switches for controlling the in and out movement of structure 11 and the operation of the ram and the up and down movement of the parallelogram.

Claims: A vehicle lift mounted to a vehicle for transporting a person having limited mobility comprising an inner mounting structure (11) and an outer lift platform (27), the inner mounting structure (11) being coupled to an outer support structure, the platform (27) being deployable for operation between a raised position and a lowered position by means comprising a parallelogram arrangement (20) having first upper side elements (21, 21a) and second lower side elements (22, 22a), said first upper side elements and said second lower side elements having inner pivotal connections (23, 24) with said inner mounting structure (11), and a pivotal part (114) hingedly attached to said platform (27) and acting as a roll stop moveable between an upright safety position and a lowered deployment position; characterised in that said outer support structure is comprised of elongated members (40, 41) attached to the vehicle wherein the inner mounting structure (11) is moveable in a horizontal sliding movement within said outer support structure (40, 41) between an inner position and an outer position and the movement of pivotal part (114) being activated by engagement of at least one ground engaging means (131) with the ground surface. A vehicle lift as claimed in claim 1 characterised in that outer pivotal connections (23a, 24a) connect said parallelogram arrangement (20) to said platform, and the parallelogram is modified such that the space between the inner pivotal connections (23, 24) is shorter than the space between the outer (23a, 24a) pivotal connections. A vehicle lift as claimed in claim 1 or claim 2, characterized in that the first upper side elements (21, 21a) are longer than the second lower side elements (22, 22a). A vehicle lift as claimed in any one of the preceding claims wherein said parallelogram is an unequal parallelogram arrangement (20) whereby to carry said platform structure so as to change the inclination of the platform (27) as it moves between the raised and lowered positions so as to incline the platform (27) downwards when the platform (27) is in the lowered position and to incline the platform (27) upwards when the platform (27) is in the raised position. A vehicle lift in any one of the preceding claims, characterised in that the inner mounting structure (11) includes a hydraulic piston (34) for raising and lowering the parallelogram arrangement (20). A vehicle lift as claimed in any one of the preceding claims, characterised in that the platform (27) can be raised and lowered independent of the position of the mounting structure (11) relative to the outer support structure (40, 41). A vehicle lift as claimed in any one of the preceding claims wherein said elongated members (40, 41) include a curved portion whereby said platform (27) is received in said outer support structure to be stored in an included position with respect to the vehicle. A vehicle lift as claimed in any one of the preceding claims including a motor means for driving said parallelogram arrangement between the upper and lower positions. A vehicle lift as claimed in any one of the preceding claims wherein movement of pivotal part (114) is activated by engagement of ground engaging means (131) of the platform (27) with the ground surface through a link (133) between the pivotal part (114) and ground engaging means (131). A vehicle lift mounted to a vehicle for transporting a person having limited mobility comprising an inner mounting structure (11) and an outer lift platform (27), the inner mounting structure being coupled to an outer support structure, the platform (27) being deployable for operation between a raised position and a lowered position by means comprising a parallelogram arrangement (20) having first upper side elements (21, 21a) and second lower side elements (22, 22a), said first upper side elements and said second lower side elements having inner pivotal connections (23, 24) with said inner mounting structure (11), and a pivotal part (114) hingedly attached to said platform (27) and acting as a roll stop moveable between an upright safety position and a lowered deployment position; characterized in that the outer support structure is comprised of elongated members (40, 41) attached to the vehicle wherein the inner mounting structure (11) is moveable in a horizontal sliding movement in said elongated members and said parallelogram arrangement is modified to define an unequal parallelogram whereby to carry the platform (27) so as to change the inclination of the platform (27) as it moves between the upper and lower positions and whereby the platform (27) moves in a substantially horizontally inclined movement during deployment of the platform (27). A vehicle lift as claimed in claim 10 characterised in that outer pivotal connections (23a, 24a) connect said parallelogram arrangement (20) to said platform (27), and the parallelogram arrangement (20) is modified such that the space between the inner pivotal connections (23, 24) is shorter than the space between the outer (23a, 24a) pivotal connections. A vehicle lift as claimed in claim 10 or claim 11, characterised in that the first upper side elements (21, 21a) are longer than the second lower side elements (22, 22a). A vehicle lift as claimed in claims 10-12, characterized in that said parallelogram arrangement (20) is an unequal parallelogram arrangement whereby to carry said platform structure so as to change the inclination of the platform (27) as it moves between the raised and lowered positions so as to incline the platform (27) downwards when the platform (27) is in the lowered position and to incline the platform (27) upwards when the platform (27) is in the raised position. A vehicle lift as claimed in claims 10-13, characterized in that movement of pivotal part (114) is activated by engagement of at least one ground engaging means (131) with the ground surface. A vehicle lift as claimed in claims 10-14, characterized in that movement of pivotal part (114) is activated by engagement of ground engaging means (131) of the platform (27) with the ground surface through a link (133) between the pivotal part (114) and ground engaging means (131). A vehicle lift as claimed in claims 10-15 including a motor means for driving said parallelogram arrangement between the upper and lower positions

Inventors: FRETWELL PERCY, FRETWELL, PERCY
Applicants: RICON UK LTD, RICON UK LIMITED
Application year: 1989
Main classification: B60P1
IPC codes: A61G3, B60P1