JPH0259901B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an emergency stop device for an elevating work platform.

For example, as shown in the perspective view of FIG. 1, a casing stamping board installed in an oil drilling derrick projects horizontally from a vertical guide rail 1, and has a slide frame 2 at its base end. is raised and lowered along the guide rail 1 by winding up and unwinding the chain 3 that suspends it.

Here, 4 is a platform, 5 is a support, 6 is a chain handrail, and 7 is a hook.

However, this type of casing stabbing board is not conventionally equipped with an emergency stop device, so if an accident such as chain hoist brake failure or chain breakage occurs during operation of the casing stabbing board, the casing stabbing board will stop. If a derrickman is on the board, it may fall and break, which not only makes it impossible to carry out excavation work, but also poses a risk of personal injury.

The present invention was proposed in view of the above circumstances, and an object of the present invention is to provide a safe emergency stop device for a lifting work platform that prevents falling accidents.

To this end, the present invention provides an elevating work platform in which a work platform is slidably mounted along a pair of parallel guide rails in the vertical direction, and the work platform is suspended via a chain or a wire rope to be raised and lowered. A plurality of inward stopper members protruding from opposing inner surfaces of the guide rail at regular intervals in the longitudinal direction, and a slide frame constituting the suspension sliding part of the workbench, with the center part above the The lower end of a chain or wire rope that suspends the slide frame is latched to a hook, and both ends are wrapped around pulleys pivotally attached to the lower left and right ends of the slide frame, respectively, and the lower ends of the slide frame are connected via springs respectively. A wire rope fixed to and stretched in an isosceles triangular shape, the center portions of which are pivoted near both lower ends of the slide frame, outer ends of which extend to the opposite side of the guide rail, and springs at both ends of the wire rope. A pair of left and right stopper levers are engaged with the engaging portion of the wire rope and each has a free inner end and extends in a direction substantially opposite to the outer end. The free ends of the stopper levers rotate toward the inner surfaces of the opposing guide rails and come into contact with the inward stopper members, thereby stopping the workbench from falling.

An embodiment in which the present invention is applied to a casing stabbing board for an oil drilling derrick will be explained with reference to the drawings. FIG. 2 is a perspective view thereof, and FIG.
Figure 4 is a partially exploded enlarged view showing the slide frame of the platform in Figure 2;
6, 7, and 8 are partial horizontal sectional views taken along the lines --, --, --, and -- in FIG. 4, respectively.

In the above diagram, the same symbols as those in FIG. 12 is a lower side member 14 of the slide frame 2a, which is suspended from the hook 7 of the chain 3 through
Connecting bars 15 and 15' rigidly connect the center part of the top member 13 to the center part of the top member 13, respectively.
The left and right upper guide sheaves 16 and 16', which are pivoted symmetrically near the center of the lower side member 14, are
The left and right lower guide sheaves 17 and 17', which are pivotally mounted symmetrically near both ends of the lower member 14, have one end engaged with an eye protruding from the right end and left end of the lower member 14, respectively, and the other end thereof Left and right springs 18 extending in parallel to the left and right ends of the lower side member 14 are wire ropes stretched in a substantially isosceles triangular shape, the apex of which is hung around the hook 7 of the chain 3, and the left and right hypotenuses are respectively The upper guide sheaves 15, 15' are passed around the left and right lower guide sheaves 16, 16', and then the lower ends are the left ends of the left and right springs 17, 17', respectively.
It is locked on the right end. Reference numerals 19 and 19' denote left and right guide pipes which are installed obliquely in an eight-figure shape between the upper side member 13 and the lower side member 14, respectively, and into which the wire rope 18 is inserted, and 20 and 20' have left and right vertical pins 21 and 21 in the center, respectively. The left and right stopper levers are rotatably supported in a horizontal plane which are pivotally mounted near the left and right ends of the lower side member 14 through the stopper levers 20 and 20'. The left and right ends and the left and right ends of the left and right springs 17, 17' form connecting portions, and the tips of the long inward arms extend as free ends in the opposite direction to the outward arms. 22 is a stopper provided protruding from the upper surface of the center part of the lower side member 14 to regulate the position of the left and right stopper levers 20, 20' during normal operation; 23, 23' are longitudinally provided on the inner facing surfaces of the guide rails 1a, 1a', respectively. These are a plurality of left and right stoppers protruding from each other and facing each other at regular intervals.

In such a device, when normal operation is performed, the wire rope 18 is held by the springs 17 and 1 by the hook 7, as shown in FIG.
7' and tensioned into a substantially isosceles triangular shape, the stopper levers 20, 20' being pulled at the outer ends of their outward arms by the lower ends of the wire ropes 18, as shown in FIG. The inward arm of the lever rotates to position Q and abuts against the stopper 22 in a figure eight shape.

However, if an accident occurs such as the chain 3 breaking or the brake of the chain hoist not working, the wire rope 18 will loosen and the springs 17 and 17' will each elastically contract.
Since the outward arm ends of the stopper levers 20, 20' are pulled, the stopper levers 20, 20' rotate around the vertical pins 21, 21', and their inward arm ends move from position Q to position P, respectively, and move toward the guide rail 1a. .

According to such a device, in the event of chain breakage, brake failure of the chain hoist, etc., the falling of the platform is automatically and immediately stopped, thereby preventing loss of human life and damage to machinery.

In short, according to the present invention, in an elevating work platform in which a work platform is slidably attached along a pair of parallel guide rails in the vertical direction and the work platform is lifted and lowered by suspending the work platform via a chain or a wire rope, A plurality of inward stopper members protrude from opposing inner surfaces of the parallel guide rails at regular intervals in the longitudinal direction, and a central portion attached to the slide frame constituting the suspension sliding portion of the workbench. The lower end of a chain or wire rope that suspends the slide frame is locked to a hook, and both ends are engaged with pulleys pivoted to the lower left and right ends of the slide frame, respectively, and then attached to the lower end of the slide frame via springs. A wire rope is fixed and stretched in a substantially isosceles triangle shape, and the center portions are pivoted near both ends of the lower part of the slide frame, and the outer ends extend to the opposite side of the guide rail, and the wire ropes are connected to springs at both ends of the wire rope. A pair of left and right stopper levers are engaged with the engaging portion of the wire rope, and each of the inner ends is a free end and extends in a direction substantially opposite to the outer end. The free ends of the stopper levers rotate toward the inner surfaces of the opposing guide rails and come into contact with the inwardly facing stopper members, thereby stopping the workbench from falling, thereby enabling a safe emergency stop of the elevating workbench. The present invention is industrially extremely useful because it provides a device.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a casing stabbing board in a known oil drilling derrick, and FIG. 2 is a perspective view showing an embodiment in which the present invention is applied to a casing stabbing board for an oil drilling derrick.
Figure 3 is a front view of Figure 2, Figure 4 is a partially exploded enlarged view showing the slide frame of the platform in Figure 2, and Figures 5, 6, 7, and 8 are respectively FIG. 4 is a partial horizontal sectional view taken along lines --, --, --, -- in FIG. 4. 1a, 1a'...Guide rail, 2a...Slide frame, 3...Chain, 4...Platform,
5... Post, 6... Chain handrail, 7... Hook,
10...Eye plate, 11...Shackle, 12...
Connection bar, 13... Upper side member, 14... Lower side member, 1
5, 15'... Upper guide sheave, 16, 16'... Lower guide sheave, 17, 17'... Spring, 1
8...Wire rope, 19,19'...Guide pipe, 20,20'...Stopper lever, 21,2
1'... Vertical pin, 22... Stopper, 23, 23'... Stopper.

Claims (1)

[Claims] 1. In an elevating workbench in which a workbench is slidably mounted along a pair of parallel guide rails in the vertical direction and the workbench is raised and lowered by suspending the workbench via a chain or wire rope, the parallel guide rails are opposite to each other. a plurality of inward stopper members protruding from opposite sides at regular intervals in the longitudinal direction on the inner surface of the workbench; The lower end of the chain or wire rope is hooked to the hook, and both ends are looped around pulleys pivoted to the lower left and right ends of the slide frame, respectively, and then fixed to the lower end of the slide frame via springs. Wire ropes stretched in an equilateral triangle shape, the center portions of which are pivoted near both ends of the lower part of the slide frame, and the outer ends of which extend to the opposite side of the guide rail and engage with the springs at both ends of the wire rope. It is provided with a pair of left and right stopper levers that are locked and each has a free inner end and extends in a direction substantially opposite to the outer end, and when the wire rope is loosened, the free ends of the pair of stopper levers are respectively biased by the spring. An emergency stop device for an elevating work platform, characterized in that the work platform is stopped from falling by rotating toward the inner surfaces of opposing guide rails and abutting against inward stopper members thereof.