GB2201138A

GB2201138A - Self-propelled articulating and elevating apparatus

Info

Publication number: GB2201138A
Application number: GB08728312A
Authority: GB
Inventors: Azam Sajjad Qureshi; James Lawrence O'hanlon
Original assignee: CALAVAR CORP
Current assignee: CALAVAR CORP
Priority date: 1987-02-10
Filing date: 1987-12-03
Publication date: 1988-08-24
Anticipated expiration: 2007-12-03
Also published as: JPS63196498A; GB8728312D0; GB2201138B; FR2610614A1; FR2610614B1; DE3742508A1

Description

220 11 -- L 6 n U ry SELF-PROPELLED ARTICULATING AND ELEVATING APPARATUS

FIELD OF THE INVENTION

This invention relates to improvements in platform elevating apparatuses. which are self-propelled. and are useful to carry an operator on a level platform to predetermined heights with an envelope of operation greater than the outside dimension of the apparatus.

BACKGROUND OF THE INVENTION

It has long been established that there is a need in plants. warehouse facilities and construction sites for selfpropelled platform elevating devices which can safely lift an operator to a height of approximately twenty feet or more from a starting height of approximately four to five feet. It is desirable that these types of devices be self-propelled to afford the operator great mobility in the job e nvironment in which the device is operating. it is also desirable that these types of devices have a collapsed height of less than six feet and six inches to permit passage through doors and passageways within a warehouse.or plant facility. it is further desirable that these types of devices have an 91overreach11 to permit the operator a greater envelope of operation than simply the outside dimension of the base of the elevating device or the platform. In this manner the device may be pulled up to a wall or relatively low 2.1 structure and the platform may be extended over the structure to permit unimpeded work above the wall or structure.

In simpler forms of these devices there is a scissor configuration in which a flat platform is attached to a criss cross structure in which the criss-cross members are pivotally attached to each other and a power element is provided to lift the platform. The criss-cross members maintain the platform in a level state and also provide for extended height of the platform depending upon the amount of power applied to the scissor & members. Such devices have the inherent limitation in that they do not provide for "overreach" of the platform. Such devices may also be provided with platforms capable of limited travel on rails to achieve some reach. In such devices the extended platform has reduced load capacity.

Another type of device is that illustrated by United States Letters Patent No. 3,807,575 to Merrick in which an elevating device is shown which comprises three vertically extending post members arranged in two pairs with a motor operated parallelogram linkage between each pair. Important to the operation of the Merrick device is that the center post is skewed in shape and the two linkages extend in opposite directions to be moveable alongside each other in the lower or stored configuration of the device. In this manner an extremely compact configuration is possible in a stored position yet the height of the vertically extending post members and the length of the linkages provide that the platform can extend in operation to substantial heights.

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Another such device is illustrated in United States Letters Patent No. 4,, 019,,604 to Benson, wherein an apparatus is disclosed for elevating a platform to permit workers, tools and equipment to be raised to a predetermined level. In Benson parallelogram boom assemblies support the platform from a mobile frame to permit the platform to be raised and lowered in a level attitude. Each of the boom assemblies comprises a compression arm and a tension arm. The boom assemblies are interconnected by means of a floating frame and a rigid tension member which is a arranged to raise and lower the upper boom assembly relative to the floating frame as the lower boom assembly is raised and lowered relative to the mobile frame. Various configurations are provided in Benson and in one embodiment an upstanding support carries the lower boom assembly which inclines downwardly in the retracted position and connects through a floating frame with an upward boom assembly which is formed with a zigzag shape.

Another such device is shown by United States Letters Patent No. 3,828, 939 to Trancherp in which a crane is provided with a principal or first hydraulic lift stage and cooperates with a first lever system and with two secondary hydraulic stages for controlling the movement of two further lever systems that are mutually pivoted with respect to each other and with respect to the first stage through intermediate lever mechanisms which do not have their own hydraulic plunger and which are actuated in movement by the movemqnt of the first lifting stage.

Reference is also made to United States Letters Patent No. 4.,429,763 to Houck and United States Letters Patent No.- 4,185,426 to Prescott, which illustrates further embodiments of boom type assemblies which have lever arms controlled by hydraulic motors to permit a platform to be elevated.

It is also known that such types of assemblies are commercially available from companies such as J.L.G., Hyster, formally known as Fabtek, Genie Industries,, Reach It Systems, Inc., Stratolift, Inc., Platforms Fabrication, Inc., Anthes High Reach, Inc., Simon Aerials, and various subsidiaries of Simon Aerials.

In prior devices, limited reach is provided by a crisscross configuration wherein the arm members are permitted to criss-cross in the stored position yet when fully extended permit elevated heights of operation. This is achieved by a skewing of the post members with respect to each other resulting in inherent instability caused by assymetrical weight distribution. Further, eccentric column loading exists in-these devices which must be compensated for by greater structure and corresponding weight. In other prior devices no reach is provided because of the configuration of the arm members. Further, in other devices a complicated pattern of linkages and arm assemblies is provided which requires considerable maintenance and increases the costs of manufacture.

OBJECT AND SU MR Y OF THE INVENTION It is a general objective of the present Invention to provide a new and improved self-propelled apparatus for elevating a platform, wherein the apparatus provides for overreach of the 4 1 S platform outside the dimensions of the base in either direction of operation.

Another object of the present invention is to provide an apparatus which is simple in construction and requires little maintenance.

Another object of the pres ent invention is to provide an apparatus which ha's inherently greater stability because of a construction wherein the extending arm members are stacked one upon the other as opposed to skewed.

a It Is another object of the present invention to provide a self-propelled moveable base with multiple post means operative to provide pivotal points for a plurality of arms which are operated by power assemblies to extend the arms and provide for a raising of a platform for operation. wherein the arms have' assemblies to maintain the platform in a level operating condition.

The self-propelled articulating and elevatingapparatus of the present invention includes, in slimmary, a moveable base carrying power equipment to permit movement of the base wherein the power equipment may comprise either an internal combustion engine or batteries. The moveable base has attached at one end a first post member which extends upwardly from the edge of the base and is provided with a pivotal attachment point at Its uppermost end. A first arm is pivotally attached to the first post member and extends to a second post member wherein it is also pivotally attached. A first linkagerember extends parallel to the first arm and is also attached to the first post member 6 and the second post member. -A first hydraulic motor is attached to the first arm and also to the first post member or to the base to provide for independent articulated movement of the first arm and elevation of the platform. The second post member has attached to it a second arm which is pivotally attached to a portion of the second post member opposite the attachment of the first arm. The second arm is attached to a third post member which is rigidly affixed to a platform. A second linkage member extends parallel to the second arm and is also attached to the second post member and-also to the third post member, and provides for leveling of the platform. A second hydraulic motor is attached to the second arm and also to the second post member to provide for independent articulated movement of the-second arm and elevation of the platform.

It should be observed that in this configuration the first arm and second arm are stacked one upon the other and not skewed which increases the stability of the platform.

The foregoing and additional objects and features of the present invention will become apparent from the following description in which the preferred embodiment has been set forth in detail in conjunctio n with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 Is a top view of the self-propelled base illustrating the steering capability of the base; Figure 2 is a side elevation view showing the self- 1 propelled articulating and elevating apparatus of the present invention in a stored configuration; Figure 3 Is a side elevation view of the self-propelled articulating and elevating apparatus of the present invention Illustrating articulated movement of the first arm of the apparatus to raise the platform to a predetermined level with overreach achieved; Figure 4 is a side elevation view of the self-propelled articulating and elevating apparatus of the present invention illustrating articulated movement of the second arm without articulated movement of the first arm to elevate the.platform to a predetermined height with overreach achieved; Figure 5 is a side elevation view of the self-propelled articulating and clevating.apparatus of the present invention in a fully extended configuration.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings. a self-propelled articulating and elevating apparatus 10 made in accordance with the present invention is shown in Figure 2. The articulating and elevating device 10 includes a base 12. also shown in Figure 1, which has a forward section 14 to which is pivotally attached wheels 16 which are actuated by a hydraulic Steering piston is to rotate the wheels 16 and Steer the device 10. The rear wheels 20 are born on an axle and propel the device 10.

Referring again to Figure 2. the base 12 has a power plant 30 In which Is contained either a self-contained internal (T combustion engine or a-plurality of rechargeable batteries. The use of an independent power system permits flexibility in the operation of device 10, wherein it can be controlled independently by an operator for movement around a plant,, warehouse or job location. Suitable controls are provided with the device 10 to permit actuation of the power plant 30 for independent movement of the device 10.

At the forwardmost portion of the base 12,, a first post member 32 extends upwardly from the base 12 and is provided with a pivot 34 at its uppermost portion. Attached to the post member 32 is a plate 36 which is shaped to extend Inwardly from the post member 32. A first arm 40 is pivotally attached to the post member 32 at the pivot 34. The first arm 30 is sized such that when articulated to its lowermost position it fits in an angular relationship to the base 12 and does not extend past the outwardmost dimension of the-base 12 and wheel 16 assembly. Attached substantially to the middle of the first arm 40 is a plate 42 which is shaped such that a pivot 44 is located a selected distance from-the arm 40. Extending between the pivot 44 and another pivot 46 located along the plate 36 is a hydraulic motor 50 which is actuated by the supply of hydraulic fluid under the control of the power'plant 30 and the operator controls (not shown). It should be appreciated that although-the hydraulic motor 50 is shown in the preferred embodiment other power sources may be used which achieve equivalent results.

A second post member 52 has a plate 54 attached to its lowermost portion to provide a pivot 56 removed a selected 11 4 9 - distance from the post member 52. The first arm 40 is pivotallyattached to the pivot 56 and provides for articulated movement of the am 40 with respect to the post member 52. A linkage assembly 58,, one side of which is not shown,, is attached-to a pivot 60 located along the plate 54 and post member 52 wherein the linkage assembly 58 extends parallel to the first arm 40 to a position where the linkage 58 is attached to the plate 36 at the pivot 46. This linkage assembly 58 provides for vertical orientation of the second post member 52,, as will be discussed in greater detail hereinafter.

Attached to an uppermost section of the second post member 52 is a plate 62 which is provided with a pivot 64 to place the pivot 64 a predetermined distance from the second post member 52. At the top oi'the plate 62 there La a second pivot 66 which also extends through the post member'52. A second arm 70 is pivotally attached to the second post =ember 52 at the pivot 66 and is sized such that the---second arm 70 when the device is in the contracted or stored position lies on top of the first arm 40 and in an angular orientation with respect to the base 12. The second arm 70As sized such that the platform will not extend past the outside dimension of the base 12 and wheel assembly.

A third post member 72 has a plate 74 which is rigidly attached to the post 72 wherein the plate 74 has a pivot 76 located a selected distance inside of the post member 72 and further includes a second pivot 78 which extends through the plate 74 and the third post member 72. The second arm 70 extends between the pivot 66 and the pivot 76. A second linkage assembly to 80, one side of which is not shown, is pivotally attached to the plate 62 and the plate 74 at the pivots 64 and 78 respectively. The second linkage assembly 80 is parallel to the second arm 70 and provides for leveling of the platform, as will be described hereinafter. A second hydraulic motor 82 is located between the pivot 64 and a pivot 84 located in a plate 86 which is attached substantially in the middle of the second arm 70. Actuation of the second hydraulic motor 82 causes articulated movement of the second arm 70 to lift the platform.

A platform 90 i%,a-ttached to an uppermost section of the third post member 72 and provides a work station for an operator. The platform 90 may include a ladder assembly 92 and sufficient railing assemblies 94 toprotect the operator. It should be appreciated that although In the preferred embodimentshown herein a rail and ladder assembly is illustrated, other protective and access assemblies may be provided to achieve the same result. Suitable controls 96 are provided on the platform 90 to permit propelling and steering of the device 10 by an operator while on the platform 90 as well as control of the articulated movement of the arms 40, 70.

In Figure 3 the forward "overreach" of the device 10 of the present invention is illustrated. In this configuration the hydraulic motor So has been actuated to cause articulated movement of the first arm 40 away from the base 12 around the pivot 34. The operation of the first linkage assembly 58 and the first arm 40 maintains the second post member 52 in a substantial,ly vertical orientation. By rotating the first arm 40 101 z 1 R X 1 in the manner shown in Figure 3 the platform 90 is positioned over the front of the base 12 and facilitates use of the device 10 In a operation which requires forward overreach. Suitable weights (not shown) in addition-to the weight of the base 12 may be placed upon the base 12 to prevent any forward tipping of the platform 90. By selective articulation of the first arm 40 various heights and overreach can he achieved. in Figure 4 the device is shown in a configuration which permits rearward "overreach". In this configuration the first arm 40 is maintained in a lowered state and the second arm 70 Is articulated around the pivot 66 located at the top portion of the second post member 52 to lift the platform 90. The articulation of the second arm 70 about the pivot 66 is facilitated by the hydraulic motor 82 which acts through the pivot 64 and pivot 84 to articulate the second arm 70. The second linkage assembly 80 operates with the second arm 70 to maintain the platform 90 in a horizontal position. In this manner rearward "overreach" is achieved whereby the platform 90 extends over the rear of the base 12 to permit operations to occur past the outside dimension of the base 12. Again. suitable weights may be provided on the base 12 to prevent rearward tipping of the device 10.

In Figure 5,, the device 10 of the present invention is shown inits fully extended configuration. In this configuration the first arm 40-has been articulated to its maximum position with respect to the base 12 by the hydraulic motor 50. The second arm 70 has also been articulated to its maximum position ("L by the hydraulic motor 82. In this configuration the platform 90 Is at Its maximum height. At its maximum height the platform 90 is located substantially over the base 12. The combined action of the first arm 40 with the first linkage assembly 58 and the second arm 70 when second linkage assembly 80 provides for horizontal orientation of the platform 90.

Significant advantages flow from use of the present device. By providing arms 70. 40 which are in a stacked relationship to one anotherf greater stability Is achieved for the device 10. In addition, the device 10 in much simpler to operate and repair. Furthermore. the nested location of the hydraulic motors between the linkage assemblies and the arms protect the motors from damage. Alsoi the coterminous location of the motors and th--,a linkage members about pivots reduce the number of moving parts which simplifies the construction and maintenance of the device 10. It should be appreciated that although linkage assemblies are shown in the preferred embodiment. other forms of platform laveling assemblies may be used. Also, the second arm 70 may be telescoping in operation to achieve oven greater overreach.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention,, and therefore the invention is not limited to what is shown In the drawings and described in detail in the specification, but only as indicated in the appended claims.

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Claims

C L A I M S

1.

comprising:

An articulating and elevating apparatus, a moveable base; first post =cans attached to said base; a first arm pivotally attached to maid first post means; second post means, said first arm pivotally attached to said second post means at a lower portion thereof; a second arm, said second arm pivotally attached to said second post means at an upper portion thereof; third post means, said second arm pivotally attached to said third post means; said third post means fUrther attached to a platform; leveling means operative with said first and second arms for maintaining said platform substantially horizontal; power means adapted to articulate said first and second arms to achieve selected overreach of said platform.

2. The articulating and elevating apparatus of claim l# including a self contained power plant operative to provide,for,independent movement of said apparatus.

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3. The articulating.and elevating apparatus of claim 2, including control means operative to selectively provide for independent articulation of said first arm and said second arm.

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4. The articulating and elevating apparatus of claim 1, wherein said power means Is a hydraulic motor assembly.

5. A self-propelled articulating and elevating 1 apparatus, comprising: a independently powered moveable base; first arm means pivotally attached to said base; second arm means pivotally attached to said first arm means; power means operative with maid first and second arm means to articulate maid first and second arm means with respect to each other; a platform attached to maid second arm means; leveling means for maintaining said platform in a substantially parallel orientation with respect to said base; and means for providing overreach of maid platform.

6. The self-propelled articulating and elevating apparatus-of claim 5 wherein said leveling means consists of a first and second linkage assembly wherein said first linkage Z.

A p assembly is operative with said first arm means and said second linkage assembly is operative with said second arm means.

7. The self-!propelled articulating and elevating apparatus of claim 5 which Includes hydraulic control means operative to Independently control articulation of maid first arm means and said second arm means.

8. An articulating and elevating apparatus constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

0 AA Published 1988 at The Patent Office, State House, 65171 High Holborn, London WCIR 4TP. Further copies maybe obtained from The Patent Office, Sales Branch, St Maxy Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1/87.