Remote activation of scissor lift cylinder prop

Abstract

A cylinder prop assembly is cooperable with a lift cylinder for a scissor lift and includes a cylinder prop displaceable between a disengaged position, in which the cylinder rod is movable relative to the cylinder housing, and an engaged position in which the cylinder rod is locked from displacement relative to the cylinder housing. An actuation lever is coupled with the cylinder prop and is accessible to displace the cylinder prop between the disengaged position and the engaged position.

Claims

1. A cylinder prop assembly acting between a cylinder rod and a cylinder housing, the cylinder prop assembly comprising: a retaining plate securable to a distal end of the cylinder rod and pivotable relative to the cylinder rod; an actuation lever coupled with the retaining plate; and a cylinder prop coupled with the retaining plate, wherein the cylinder prop is connected with the actuation lever via the retaining plate such that the cylinder prop is displaceable via operator engagement of the actuation lever between a disengaged position in which the cylinder rod is unlocked for displacement relative to the housing and an engaged position in which the cylinder rod is locked from displacement relative to the housing, wherein the actuation lever is pivotable relative to the retaining plate to pivot the retaining plate relative to the cylinder rod, wherein an end of the cylinder rod comprises a bushing having an opening therein, and wherein the cylinder prop includes an axle positionable and rotatable in the opening, the cylinder prop assembly further comprising a locking mechanism cooperable with the bushing to lock the cylinder prop in the disengaged position, wherein the locking mechanism comprises a spring-loaded plunger engageable with a hole in the bushing, wherein the spring-loaded plunger is disposed through the retaining plate and connected to the actuation lever, and wherein the actuation lever is pivotable relative to the retaining plate to retract the spring-loaded plunger.

2. A cylinder prop assembly according to claim 1, wherein the cylinder housing defines a shoulder relative to the cylinder rod, and wherein in the engaged position, the cylinder prop is disposed adjacent the shoulder.

3. A cylinder prop assembly cooperable with a lift cylinder for a scissor lift, wherein the lift cylinder includes a cylinder rod and a cylinder housing, the cylinder prop assembly comprising: a cylinder prop displaceable between a disengaged position in which the cylinder rod is movable relative to the cylinder housing and an engaged position in which the cylinder rod is locked from displacement relative to the cylinder housing; an actuation lever operatively coupled with the cylinder prop and accessible to displace the cylinder prop between the disengaged position and the engaged position; a retaining plate pivotably secured to a distal end of the cylinder rod, wherein the actuation lever and the cylinder prop are connected to and movable with the retaining plate; and a locking mechanism that is constructed to lock the cylinder prop in the disengaged position, wherein the actuation lever is cooperable with the locking mechanism to selectively disengage the locking mechanism.

4. A cylinder prop assembly according to claim 3, wherein an end of the cylinder rod comprises a bushing having an opening therein, and wherein the cylinder prop includes an axle positioned in the opening and rotatable in the opening.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects and advantages will be described in detail with reference to the accompanying drawings, in which:

(2) FIG. 1 is a perspective view of a scissor type aerial work platform;

(3) FIG. 2 shows a machine operator remotely engaging/disengaging the cylinder prop assembly while remaining clear of all pinch/crush hazards;

(4) FIG. 3 is a cut-away view showing the cylinder prop assembly in a disengaged position; and

(5) FIG. 4 is a cut-away view showing the cylinder prop assembly in an engaged position.

DETAILED DESCRIPTION OF THE DRAWINGS

(6) FIG. 1 is a perspective view of a scissor lift 10 including a scissor arm assembly 12 displaceable between a raised position and a lowered position by a lift cylinder 14 such as a hydraulic lift cylinder or the like. The scissor arm assembly 12 includes a left side arm stack and a right side arm stack connected to each other across a middle area as shown. A platform 16 is supported by the scissor arm assembly 12. The scissor lift 10 also includes a base support 18 including wheels and driving structure. Scissor lift controls are accessible to an operator on the platform 16.

(7) A cylinder prop assembly 20 acts between the scissor arm assembly 12 and the lift cylinder 14. As shown in FIG. 2, the cylinder prop assembly 20 is positioned in the middle area between the left side and right side arm stacks of the scissor arm assembly 12. In this position, an operator can safely and remotely engage and disengage the cylinder prop assembly 20.

(8) FIGS. 3 and 4 are cut-away views showing the cylinder prop assembly in a disengaged position and an engaged position, respectively. The lift cylinder 14 includes a housing 22 and a cylinder rod 24 displaceable relative to the housing 22 by hydraulic fluid. The cylinder prop assembly 20 serves to lock the cylinder rod 24 from displacement relative to the housing 22.

(9) The cylinder prop assembly 20 includes a retaining plate 26 secured to a distal end of the cylinder rod 24 and pivotable relative to the cylinder rod 24. An actuation lever 28 is coupled with the retaining plate 26, and a cylinder prop 30 is coupled with the retaining plate and displaceable via the actuation lever 28 between the disengaged position (FIG. 3) and the engaged position (FIG. 4). The cylinder housing 22 defines a shoulder 32 relative to the cylinder rod 24. As shown in FIG. 4, in the engaged position, the cylinder prop 30 is disposed adjacent the shoulder 32. An opposite end of the cylinder prop 30 includes an axle 34 that is positionable and rotatable in an opening 36 in a bushing 38 at a distal end of the cylinder rod 24. A locking mechanism 40 is cooperable with a hole 41 in the bushing 38 to lock the cylinder prop 30 in the disengaged position. Preferably, the locking mechanism includes a spring-loaded plunger 42 engageable with the hole in the bushing 38. The spring loaded plunger 42 is disposed through the retaining plate 26 and connected to the actuation lever 28. The actuation lever 28 is pivotable relative to the retaining plate 26 at pivot 44 to retract the spring loaded plunger 42 as the cylinder prop 30 is displaced from its disengaged position to its engaged position via the actuation lever 28. Thus, the actuation lever 28 is cooperable with the locking mechanism 40 to selectively disengage the locking mechanism 40.

(10) Components of the cylinder prop assembly are made of suitably strong materials such as steel or a material of similar strength and durability. The cylinder prop assembly provides a safe and effective mechanism for preventing inadvertent retraction of a scissor arm assembly during inspection and routine maintenance. The structure can be retrofit for existing machines and provides an effective solution for operator pinch/crush hazards.

(11) While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.