JPH0547140Y2 - - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention The present invention relates to a mechanism for preventing the loading platform from falling when the loading platform is raised and lowered by a scissor link.

Conventional Technology and Problems Mechanisms such as so-called down safety circuits that prevent falls on hydraulic circuits are known for this type of purpose, but there are few safety devices based on mechanical mechanisms, and only a single system safety device is available. Mostly,
There is a drawback that it cannot be trusted 100%, which is especially problematic when it affects human life.

Means for Solving the Problems This invention is a mechanical safety device other than a hydraulic circuit to solve the above-mentioned conventional problems, and uses a lock and claw system to easily prevent any change in the stopping position of the loading platform. This is an innovative safety device in which the entrance angle of the claw is the same, and by using it in parallel with the hydraulic circuit safety device, it can be used as a dual safety device with two systems.

Configuration The configuration of the present invention is that in a mechanism that raises and lowers a loading platform using scissor links, the center pin of the safety device is arranged on the same center line as the lower end slide pin of the scissor link, and the guide integrated with the center pin is connected to the guide rail. They are connected so that they slide while maintaining a constant angle, and this fixes the main center pin without rotating it.By sliding in the same way as the slide pin of a scissor link, a locking claw that uses the main center pin as the rotation axis can be attached. The safety of the lifting platform is characterized by the fact that the engagement angle of the rack and the positional relationship with the release solenoid remain unchanged, so that the safety device operates under the same conditions when the loading platform is stopped at any lifting position. It is a device.

Embodiment To explain the embodiment shown in the attached drawings, 1 is a loading platform, 2 is
3 is a scissor link, and 4 is a piston. As the piston 4 expands and contracts, the scissor links 2 and 3 also expand and contract, moving the loading platform 1 to the upper position A and the lower contracted position B (dotted line) in Figure 1. and is displaced.

Slide pins 5 and 6 provided at one end of each of the left and right scissor links 2 and 3 (the right end in FIG. 1) roll and slide on the respective guide rails 7a and 7b. The other ends of the scissor links 2 and 3 are pivotally fixed to an underframe or a loading platform, respectively.

Reference numeral 8 denotes a safety stop rack, and a claw 9 opposite to this is supported by a center pin 10.
is supported by a bracket 12 connected to a horizontal bar 11 of the scissor link 2.

The center pin 10 is integrated with a guide rod 13, and the guide rod 13 has upper and lower rollers 14 at its lower end.
The center pin 10 is guided in a fixed direction with the guide rails 15 (side mounting edges of the rack base) in between, and the center pin 10 does not rotate. Claw 9 is spring 16
It engages with rack 8 due to its own weight. Therefore, by aligning the center line of the center pin 10 with the center line of the slide pin 5 of the scissor link, the claw 9 can be kept at a constant angle with respect to the rack 8 no matter how the scissor links 2 and 3 are slid into any inclined arrangement. The bite will be restrained.

The engagement of the pawl 9 with the rack 8 can be disengaged by operating a solenoid 17 provided inside the bracket 12 opposite the pawl 9. 18 is a limit switch.

Function Normally, the claw 9 whose rotation axis is the center pin 10 of the safety device located on the same center line as the scissor slide pin 5 bites into the rack 8 due to the weight of the spring 16 and the claw 9 and acts as a safety device. It becomes a state of being.

When the lifting platform 1 is raised or lowered, a solenoid 17 incorporated in a bracket 12 supporting the center pin 10 is energized and the claw 9 is released from the rack 8. At this time, the limit switch 18 senses that the claw 9 has been reliably released.

After that, the lifting platform is raised and lowered normally for the first time.
When the lifting platform stops at an appropriate position, the power to the solenoid 17 is turned off and the claw 9 is released again.
It works as a safety device.

Effects of the invention The present invention is a mechanical lock device that can safely prevent the loading platform from falling in any position when the loading platform is moved up and down via a scissor link, and is effective when used in conjunction with a hydraulic control circuit safety device. In other words, this safety device becomes a two-system dual safety device that operates against the fall of the loading platform due to a leak in the hydraulic circuit, or a fall due to an unexpected accident in the hydraulic circuit, resulting in extremely high safety.

[Brief explanation of the drawing]

The attached drawings show an embodiment of the present invention, and Fig. 1 is an explanatory diagram of lifting and lowering the loading platform as seen from the side of the vehicle body, and Fig. 2 A, B, and B.
C and D are a perspective view, a view in the direction of arrow A, a side view, and a partially enlarged view of the side view, respectively, of the safety device section consisting of a rack and a claw. FIG. 3 is a perspective view of the scissor link. 1... Loading platform, 2, 3... Scissor link, 4...
...Piston, 5, 6...Slide pin, 7 (7
a, 7b)... Guide rail, 8... Rack, 9
...Tlaw, 10...Center pin, 11...Horizontal bar, 1
2... Bracket, 13... Guide rod, 14...
Roller, 15... Guide rail, 16... Spring, 17... Solenoid, 18... Limit switch.

Claims (1)

[Scope of utility model registration request] In a mechanism that raises and lowers a cargo platform using a scissor link, a center pin that supports a safety lock tab is placed on the same center line as the slide pin at the lower end of the scissor link, and a guide rod integrated with the center pin is aligned with the guide rail. A safety device for a lifting/lowering platform, characterized in that the locking rack is connected so as to slide while maintaining an angle, and a locking rack is provided parallel to the guide rail and opposite to the safety locking claw.