WO2015170261A1

WO2015170261A1 - A stabilizer mechanism for aerial work platform

Info

Publication number: WO2015170261A1
Application number: PCT/IB2015/053296
Authority: WO
Inventors: Atul Chandra TRIPATHI; Tinu Thomas MEPPRATH; Amit KAMBOYA
Original assignee: L&T Technology Services Ltd
Current assignee: L&T Technology Services Ltd
Priority date: 2014-05-06
Filing date: 2015-05-06
Publication date: 2015-11-12
Anticipated expiration: 2016-11-06

Abstract

According to embodiments of the disclosure, a stabilizer arrangement 100 for a self- propelled aerial work platform vehicle 10 having a work platform 18, a lifting section 16 for elevating and lowering the work platform 18 and a chassis 12 for supporting lifting section 16 and at least two safety plates 24 is disclosed. The stabilizer arrangement 100 may include a pushing element 102, at least two linkage mechanism 104 and an arc shaped resilient member 110 supported on an actuator frame 22. A first end 106 of each linkage mechanism 104 may be coupled to each safety plate 24. Each end 112 of the arc shaped resilient member 110 may be hinged to a second end 114 of each linkage mechanism 104, such that downward vertical movement of the work platform 18 may result in imparting a downward vertical movement to a center part 116 of the arc shaped resilient member 110 by the pushing element 102.

Description

A STABILIZER MECHANISM FOR AERIAL WORK PLATFORM

FIELD OF INVENTION

The invention generally relates to a stabilizer arrangement for aerial work platforms and particularly an anti-tipping or anti-toppling arrangement for Scissors lift,

BACKGROUND

Aerial work platform devices are well known in the art and are extensively used for raising material and/or workers to elevated locations. The principal purpose of such devices is to provide a safe and efficient means for supporting a working platform at any desired elevation and they work on various lifting mechanisms. Scissors lift is one of the known lifting machine used as a self-propelied type aerial work platform devices. The scissors lift comprises a pair of vertically extensible scissors linicages mounted on a chassis in laterally spaced, parallel relationship, and a workin platform mounted on top of the linkages. Typically each of the scissors linkages comprises pairs of arms plvotaliy connected to one another at their ends and at their centres. The lowermost pairs of arms of the linkages are pivoially mounted at one end to the chassis. A hydraulic drive, or lift, cylinder mechanism may be pivoially attached to the cross-bars extending between the lowermost pairs of arras of the linkages. The hydraulic mechanism serves to turn the arms of the lower most pair about their pivotal axis to extend or retract the linkages and thereby to raise, or lower the working platform.

The chassis is mounted on wheels in most of the known aerial working platform, and a drive arrangement may be provided to move the lift from one location to another. The chassis may further have an anii-tipping or anti-toppling arrangement for supporting the aerial work platform in the event one or more wheel is on an uneven surface or is driven into a pot hole. Such an apparatus works normally by reducing the ground clearance to less than one inch, b deploying safety plates, when the platform of the aerial work equipment is elevated beyond a certain height.

The known anti-tipping or anti-toppling arrangement, typically have one or more safety plates or bars, attached to the chassis of the aerial work platform devices. The safety plates may be switched between a deployed and stowed position. The safety plates are in deployed position when the aerial work platform device is in elevated position to reduce the ground clearance. However the safety plates remains in stowed position when the aerial work platform device is in folded or resting position. Typically arrangements for switching the safety plates between deployed and stowed position are complex and have various parts that in turn results in high cost and low reliability.

The present invention is directed to overcoming one or more of the problems as set forth above.

SUMMARY OF THE INVENTION

According to embodiments, a stabilizer arrangement for a self- propelled aerial work platform vehicle having a work platform, a lifting section for elevating and lowering the work platform and a chassis for supporting the lifting section and at least two safety plates. The safety plates may be provided for inhibiting tipping over of the aerial work platform vehicle is disclosed. The stabilizer arrangement includes a pushing element extending downward from the lifting section, at least two-linkage mechanism and an arc shaped resilient member. A first end of each linkage mechanism is coupled to each safety plate. Each end of the arc shaped resilient member is hinged to a second end of each linkage mechanism, such that downward vertical movement of the work platform results in imparting a downward vertical movement to a center part of the arc shaped resilient member by the pushing element. The arrangement being such that the vertical movement of the center part of the arc shaped resilient member results in hinged movement of the safety plates.

According to yet another embodiment, a stabilizer arrangement for a self- propelled aerial work platform vehicle having a work platform, a lifting section for elevating and lowering the work platform for supporting the lifting section and at least two safety plates for inhibiting tipping over of the aerial work platform vehicle is disclosed. The stabilizer arrangement includes a pushing element extending downward from the lifting section for vertically moveable up on rise of the work platform and down in response to lowering of the work platform. The stabilizer arrangement further includes at least two linkage mechanism and an arc shaped resilient member. A first end of each linkage mechanism is coupled to each safety plate. Each end of the arc shaped resilient member is hinged to a second end of each linkage mechanism, such that downward movement of the pushing element, beyond a predefined height, pushes a center part of the arc shaped resilient member to actuate the linkage mechanisms thereby imparting a hinged movement to the safety plates.

BRIEF DESCRIPTION OF DRAWINGS

Other objects, features, and advantages of the invention will be apparent from the following description when read with reference to the accompanying drawings. In the drawings, wherein like reference numerals denote corresponding parts throughout the several views:

Figure 1 illustrates an isometric view of an exemplary aerial work platform;

Figure 2 illustrates a cross section view of an exemplary stabilizer arrangement for a self- propelled aerial work platform according to an embodiment of the invention; Figure 3 illustrates a cross section view of the exemplary stabilizer arrangement for a self- propelled aerial work platform according to another embodiment of the invention; and Figure 4 illustrates a partial isometric view of the exemplary stabilizer arrangement for a self- propelled aerial work platform according to an embodiment of the invention.

DETAILED DESCRD7TION OF DRAWINGS

Figure 1 illustrates an isometric view of an exemplary aerial work platform 10 that may accommodate disclosed stabilizer arrangement according to an embodiment of the invention. Although the disclosed arrangement may be applicable to other types of lifting devices/arrangements, the aerial work platform 10 shown in Figure 1 is only for illustration purpose. The aerial work platform 10 may include chassis 12 supported on a plurality of wheels 14. A lifting section 16 is provided on the chassis. According to an exemplary embodiment, the lifting section 16 may include a plurality of scissor members arranged in a conventional criss-cross manner to elevate and support a work platform 18. A lifting element 20 such as, but not limited to a hydraulic cylinder may be pivotally attached to a lower in board arm scissor member and pivotally attached to one of upper in board arm scissor member at the other end. The lifting element 20 may raise or lower the work platform 18. The aerial work platform 10 may further have an actuator frame 22 connected to the chassis 12 and a plurality of safety plates 24.

Figure 2 and Figure 3 illustrates a cross sectional view of an exemplary stabilizer arrangement for a self- propelled aerial work platform in deployed and stowed positions respectively according to an embodiment of the invention. The disclosed stabilizer arrangement 100 may include a pushing element 102 extending downward from the lifting section 16. According to an embodiment, the pushing element 102 may be a cylindrical member with a contact surface mechanically connected to one of the scissor members. The stabilizer arrangement 100 may further include at least two linkage mechanism 104. According to an embodiment, one linkage mechanism 104 may be provided in proximity to each safety plate 24 and a first end 106 of each linkage mechanism 104 may be coupled to each safety plate 24 as illustrated.

Figure 4 illustrate a partial isometric view of the exemplary stabilizer arrangement according to an embodiment of the invention. As illustrated, each linkage mechanism 104 may have a plurality of linkage bars such that each bar may be hinged to the other bar and at least one of the linkage bars from the plurality of linkage bars may be connected to the actuator frame 22 through sliding pin joint 108. According to yet another embodiment, each linkage mechanism 104 has at least two linkage bars 104a, 104b.

The disclosed stabilizer arrangement 100 may further include an arc shaped resilient member 1 10. Each end 1 12 of the arc shaped resilient member 1 10 may be connected to a second end 1 14 of each linkage mechanism 104 through a sliding pin joint. According to an exemplary embodiment the arc shaped resilient member 110 may be a leaf spring. According to yet another embodiment, a guiding member 122 may be provided to guide the vertical movement of the arc shaped resilient member 1 10 as illustrated in figure 4. The guiding member 122 may be supported on the actuator frame 22 and may pass through an opening provided in the arc shaped resilient member 1 10.

According to another embodiment, the downward vertical movement of the work platform 18 may result in imparting a downward vertical movement to a centre part 1 16 of the arc shaped resilient member 1 10 through the pushing element 102. According to yet another embodiment, the disclosed stabilizer arrangement 100 being such that the vertical movement of the centre part 1 16 of the arc shaped resilient member 1 10 results in hinged movement of the safety plates 24.

According to another embodiment, the disclosed stabilizer arrangement 100 may include a pushing element 102 extending downward from the lifting section 16. According to an embodiment, the pushing element 102 may be a cylindrical member with a contact surface mechanically connected to one of the scissor members. The pushing element 102 may vertically moveable up on rise of the work platform 18 and down in response to lowering of the work platform 18.

The stabilizer arrangement 100 may further include at least two linkage mechanism 104. According to an embodiment, one linkage mechanism 104 may be provided in proximity to each safety plate 24 and a first end 106 of each linkage mechanism 104 may be coupled to each safety plate 24 as illustrated. According to yet another embodiment, each linkage mechanism 104 may have a plurality of linkage bars such that each bar may be hinged to the other bar and at least one of the linkage bars from the plurality of linkage bars may be connected to the frame 22 through a sliding pin joint 108. According to yet another embodiment, each linkage mechanism 104 has at least two linkage bars 104a, 104b.

The disclosed stabilizer arrangement 100 may further include an arc shaped resilient member 1 10. Each end 1 12 of the arc shaped resilient member 1 10 may be connected to a second end 1 14 of each linkage mechanism 104 through a sliding pin joint. According to an exemplary embodiment the arc shaped resilient member 110 may be a leaf spring. According to another embodiment, the downward vertical movement of the work platform 18 beyond a predefined height, pushes a centre part 1 16 of the arc shaped resilient member 1 10 to actuate the linkage mechanisms 104 thereby imparting a hinged movement to the safety plates 24.

According to yet another embodiment the hinged movement of the safety plates 24 results in moving the safety plates 24 from a deployed position 1 18 to a stowed position 120 when the work platform 18 is lowered beyond a predefined height. According to an embodiment, the safety plates 24 is preferably pivoted through an arc that is limited to 90 degree between deployed position 1 18 and stowed position 120. According to an exemplary embodiment, the predefined height may be approximately 5 to 6 inch more than platform height in stowed position.

In the foregoing detailed description of embodiments of the invention, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description of embodiments of the invention, with each claim standing on its own as a separate embodiment.

It is understood that the above description is intended to be illustrative, and not restrictive. It is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined in the appended claims. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein," respectively.

Claims

We claim:

1. A stabilizer arrangement for an aerial work platform vehicle having a work platform, a lifting section for elevating and lowering the work platform and a chassis for supporting the lifting section and at least two safety plates, the safety plates being provided for inhibiting tipping over of the aerial work platform vehicle, the stabilizer arrangement comprising:

a pushing element extending downward from the lifting section;

at least two linkage mechanism, such that a first end of each linkage mechanism is coupled to each safety plate; and

an arc shaped resilient member, wherein each end of the arc shaped resilient member is hinged to a second end of each linkage mechanism, such that downward vertical movement of the work platform results in imparting a downward vertical movement to a center part of the arc shaped resilient member by the pushing element, the arrangement being such that the vertical movement of the center part of the arc shaped resilient member results in hinged movement of the safety plates.

2. A stabilizer arrangement for an aerial work platform vehicle having a work platform, a lifting section for elevating and lowering the work platform and a chassis for supporting the lifting section and at least two safety plates, the safety plates being provided for inhibiting tipping over of the aerial work platform vehicle, the stabilizer arrangement comprising:

a pushing element extending downward from the lifting section for vertically moveable up on rise of the work platform and down in response to lowering of the work platform; at least two linkage mechanism, such that a first end of each linkage mechanism is coupled to each safety plate; and

an arc shaped resilient member, wherein each end of the arc shaped resilient member is hinged to a second end of each linkage mechanism, such that downward movement of the pushing element, beyond a predefined height, pushes a center part of the arc shaped resilient member to actuate the linkage mechanisms thereby imparting a hinged movement to the safety p ates.

3. The stabilizer arrangement as claimed in claim I or 2, wherein the hinged movement of the safety plates results in moving safety plates from a stowed position to a deployed position when the work platform is elevated beyond a predefined height.

4. The stabilizer arrangement as claimed in claim 1 or 2, wherein the hinged movement of the safety plates results in moving safety plates from a deployed position to a stowed position when the work platform is lowered beyond a predefined height.

5. The stabilizer arrangement as claimed in claim 1 or 2, wherein the arc shaped resilient member is supported on an actuator frame.

6. The stabilizer arrangement as claimed in claim 5, wherein the each linkage mechanism having a plurality of linkage bars being hinged to each other, such that at least one of the linkage bars from the plurality of linkage bars being hinged to the actuator frame.

7. The stabilizer arrangement as claimed in claim 1 or 2, wherein the arc shaped resilient member is a leaf spring. The stabilizer arrangement as claimed in claim 6, wherein the each linkag mechanism have at least two linkage bars.