JPH026068Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is designed to prevent overloads in traction devices used when towing lifeline main ropes at construction sites or when tightening ropes for securing loads during truck transport. This invention relates to a prevention device.

[Prior art]

Conventionally, as a traction device, as disclosed in Japanese Utility Model Publication No. 43-25242, a support shaft is integrally connected to one side of a load sheave around which a chain is wound, and a support shaft is attached to the other side of the load sheave. A ratchet wheel, a support shaft, and a rotary tool engagement shaft are sequentially arranged in series and connected integrally, and the support shafts on both sides of the load sheave are rotatably supported by a frame, and the frame includes:
A claw metal fitting to be engaged with the ratchet wheel is pivotally connected by an engagement spring, and the other end of a locking chain having a hook at one end is connected, and the load sheave is provided with a hook at one end. There is known a structure in which a traction chain equipped with a hook is wound around, and a rotary tool such as a lever is removably fitted to the rotary tool engagement shaft.

[Problem that the invention attempts to solve]

However, in the case of the conventional traction device, if an excessive rotational force is applied to the rotating tool and the load sheave is rotated, an overload is applied, which causes excessive tension to be applied to the traction chain, causing the chain to break. Otherwise, excessive binding force may be applied to the baggage, causing damage to the baggage.

[Purpose of the invention, structure]

The purpose of this invention is to provide an overload prevention device for a traction device that can advantageously solve the above-mentioned problems. 2 and a ratchet wheel for preventing reverse rotation.
is rotatably supported by a frame 4, and a claw metal fitting 6 which is pressed by an engagement spring 5 and engaged with the ratchet wheel is pivotally attached to the frame 4, one end of the rotating body 3 A boss 7 is integrally provided on one of the square shaft portions 9 for engaging a rotating tool, and a connecting shaft 10 is integrally provided on the other, and the connecting shaft 10 is fitted into the boss 7 and This overload prevention device for a traction device is characterized in that a shear pin 11 made of a split pin is inserted across a connecting shaft 10.

〔Example〕

Next, this invention will be explained in detail using illustrated examples.

The drawing shows an embodiment of this invention, in which a large number of inclined engagement teeth 12 are provided at a constant pitch on both sides of a load sheave 2, which is provided with a chain-fitting recess around its periphery. A ratchet-cum-support shaft 14 having an arcuate bearing surface 13 located at the top of the teeth 12 is integrally provided, and each of the arcuate bearing surfaces 13 is arranged on the same circumference, and one ratchet wheel A boss 7 is integrally provided on the side of the supporting shaft 14,
Furthermore, the load sheave 2 and the ratchet wheel/support shaft 14
A shaft insertion hole 8 with a circular cross section is provided across the center of the rotating body 3 and the boss 7. Connecting shaft 1 with a circular cross section connected to the square shaft portion 9 for engaging a rotating tool
0 is rotatably fitted into the shaft insertion hole 8, and is provided with a pin hole extending across the boss 7 and the connecting shaft 10 in the diametrical direction thereof.
A shear pin 11 made of a JIS standard cotter pin is inserted, and the shear pin 11 connects the boss 7 and the connecting shaft 10.
are connected so that they do not rotate relative to each other.

A pair of frame constituent units 15 and 16 formed by pressing a steel plate have a chain entry/exit opening 17 located at the center of the lower part, and a groove-shaped chain guide 18 located at the upper part of the opening 17. , a chain stripper 19 located at the lower part of the opening 17, a semi-cylindrical part 20 located on both sides of the lower part, an end plate 21 connected to the end of the semi-cylindrical part 20, and an upper storage part. It has a recess 22, a lower end flange 23, a side flange 24, and an upper end flange 25 of double folded structure, and the lower end flange 23 and side flange 24 of each frame component unit 15, 16 are overlapped and riveted. The frame 4 is configured by being connected by 26.

The ratchet wheel/support shaft 14 on both sides of the rotating body 3
is rotatably fitted into a cylindrical portion constituted by a semi-cylindrical portion 20 of a pair of frame constituent units 15 and 16, and the boss 7, the rotary tool engaging square shaft portion 9 and the shear pin 11 are connected to the frame 4.
a pair of claw pieces 27 disposed on the outside of the wheel and engaged with the engaging teeth 12 of each of the ratchet wheels and support shafts 14; a presser plate 28 that connects the base end of each claw piece 27; and each claw piece 27. The claw metal fitting 6 consisting of a reinforcing connecting plate 29 that connects the side edges of the metal plate 6 is formed by pressing a steel plate, and the middle part of each claw piece 27 in the claw metal fitting 6 is rotatably fitted. Both ends of the support shaft 30 for the claw metal fittings are made from a round steel bar, and each frame component unit 15,
It is rotatably fitted into the circular hole formed by the semicircular hole provided in the side flange 24, and the end face of the claw metal support shaft 30 is fitted into the bottom of the notched recess 31 provided in the side flange 24. Opposed to each other, this bottom portion functions as a stopper for restricting movement of the support shaft 30 in the axial direction.

The engagement spring 5 fitted to the support shaft 30 is engaged with the frame 4 and the claw metal fitting 6, and the engagement spring 5 is engaged with the frame 4 and the claw metal fitting 6.
The pawl fitting 6 is rotated so that the pawl piece 6 is engaged with the engagement tooth 12. A square shaft portion 33 and a small diameter shaft portion 3 are provided at one end of the operating shaft 32 extending in a direction perpendicular to the support shaft 30 at the upper part of the claw metal fitting 6.
4 are integrally connected, the small diameter shaft portion 34 of which is rotatably fitted into a small diameter hole provided in one frame component unit 15, and a large diameter shaft is provided at the other end of the operating shaft 32. portion 35 and a square shaft portion 36 for fitting a rotary tool are sequentially and integrally connected to each other, and the large diameter shaft portion 35
is rotatably fitted into a large diameter hole provided in the other frame unit 16, and the square shaft portion 36 projects outward from the frame unit 16.

Inside the frame 4, a cam member 37 for holding the claw metal engaging position and a cam member 38 for holding the claw metal removal position are integrally provided on both sides of the operating shaft 32 in the longitudinal direction, and the cam members 37 and 38 are arranged at an angle of 180 degrees from each other. The cam member 37 for holding the claw fitting engagement position is arranged in different phases and is arranged to face one side of the holding plate 28 of the claw fitting 6 in the longitudinal direction of the operating shaft, and the cam member 37 for holding the claw fitting detachment position The member 14 is arranged to face the other side of the presser plate 28 in the longitudinal direction of the operating shaft.

Spring stopper 39 and pair of shaft holding arms 4
0 is disposed at the upper part of the frame 4, the spring lowering stopper 39 is disposed in contact with or close to the upper part of the square shaft part 33, and each shaft retainer arm 40 The tip of the shaft holding arm 40 is arranged to engage with both sides of the lower part of the square shaft part 33, and each time the operating shaft 32 is rotated by 90 degrees, the shaft presser arm 40 is moved against the slopes on both sides of the lower part of the square shaft part 33. The operating shaft 32 is held by the elastic holding force so as not to rotate unnecessarily.

An engaging fitting 42 consisting of a hook is connected to one end of the traction chain 1 wound around the load sheave 2, and a stopper 43 for preventing slippage is attached to the other end of the chain 1. One end of a connecting chain 44 is interposed between the upper end flanges 25 of the pair of frame constituent units 15 and 16, and a connecting bolt 45 is inserted between one end of the chain 44 and each upper end flange 25, An engaging metal fitting 46 consisting of a hook is attached to the other end of the connecting chain 44. Further, in order to enable the rotating body 3 and the operating shaft 32 to be rotated by a common rotating tool such as a spanner, a box spanner, etc., an angle between the rotating tool engaging square shaft portion 9 and the operating shaft 32 is provided. The shaft portion 36 has the same cross-sectional shape and the same cross-sectional dimensions.

When the towing device of the above embodiment is used to tow a lifeline main rope or a rope for securing cargo, as shown in FIGS. 3 and 4, each cam member 3
7 and 38 away from the presser plate 28 of the pawl fitting 6, and the engaging spring 5 engages each pawl piece 27 of the pawl fitting 6 with the engaging tooth 12 of each pawl/support shaft 14 of the rotating body 3. Next, a suitable general-purpose rotary tool (not shown) is engaged with the square shaft portion 9, and the rotary tool is used to connect the square shaft portion 9, the connecting shaft 10, the shear pin 11, and the boss 7. The rotating body 3 is rotated in the direction of arrow A in FIG. in this case,
Even if the rotational force in the towing direction is released from the square shaft portion 9 during or after towing, the claw piece 27 of the claw metal fitting 6
By the engagement of the engaging teeth 12 on the ratchet and support shaft 14, the rotating body 3 is prevented from reversing, that is, rotating in the loosening direction.

Also, by engaging the rotating tool with the square shaft portion 36 of the operating shaft 32 and rotating the operating shaft 32 by 90 degrees in the direction of arrow B from the state shown in FIGS. As shown in FIG. 10, the pawl fitting position holding cam member 37 can be brought into contact with or close to the front upper surface of the presser plate 28 of the pawl fitting 6 to lock the pawl fitting in the engaged state.

Further, by rotating the operating shaft 32 by 90 degrees in the direction of arrow C from the state shown in FIGS. 3 and 4,
The pawl fitting 6 can be rotated to the disengaging position through the pawl fitting detachment position holding cam member 38 against the force of the engagement spring 5, and the pawl fitting can be locked in the disengaging state as shown in FIG. can. In this state, by pulling the traction chain 1 by hand, the rotating body 3 can be rotated in any direction, and the length of the traction side of the traction chain 1 can be adjusted.

That is, in the case of the above embodiment, simply the operation shaft 3
By rotating 2, it is possible to switch between the claw metal detachment lock state, the claw metal engagement lock state, and the towable state.

As in the above embodiment, a pair of frame constituent units 15, 1 are constructed by press working a steel plate.
6 are connected with rivets 26 etc., and the frame 4 is assembled.
By configuring this, the frame can be made lighter and manufactured at lower cost than a cast iron frame.

In the case of the embodiment described above, the load acting on the frame 4 can be evenly distributed to the left and right and the balance can be maintained, so that the frame 4 can be made thinner and lighter. Furthermore, since the frame 4 has various functions such as a protective cover, bearing, chain guide, and chain stripper, the structure can be simplified and the number of parts can be reduced. It can be manufactured at low cost.

In the case of the above embodiment, the engaging teeth 12 are provided at a constant pitch on the side of the load sheave 2, and the arcuate bearing surface 1 is located at the top of the engaging teeth 12.
Since the rotary body 3 is constructed by integrally providing the ratchet and support shaft 14 with The length of the rotating body 3 can be shortened compared to the case where the rotating body 3 is configured, so the main body of the traction device including the rotating body 3 can be made smaller and lighter, improving the handling of the traction device. can be manufactured at low cost.

When implementing this invention, the ratchet/support shaft 14 may be provided on one side of the load sheave 2, and a support shaft with a circular cross section without engaging teeth may be provided on the other side of the load sheave 2. In this case, a claw metal fitting having one claw piece is used. Further, the engaging fitting 46 may be attached to the upper part of the frame 4 via a connecting fitting such as a universal joint.

As the engaging metal fittings 42 and 46, any other engaging metal fittings may be used instead of the hooks, and the connecting chain 44 and the engaging metal fitting 46 may be omitted and , an engaging tool made of a wire rope having an annular portion may be attached.
Furthermore, the handle is fixed to the outer end of the operating shaft 32 without providing the square shaft portion 36 for fitting a rotary tool,
The operating shaft 32 may be rotated by holding the handle by hand.

In the case of the above embodiment, the boss 7 is connected to one end of the rotating body 3, and the connecting shaft 10 is connected to the rotating tool engaging square shaft part 9. The connecting shaft 10 may be connected to one end of the rotary tool, and the boss 7 may be connected to the rotating tool engaging square shaft portion 9.

[Effect of idea]

According to this invention, one of the load sheave 2 around which the traction chain 1 is wound, one end of the rotating body 3 equipped with a claw wheel for preventing reverse rotation, and the square shaft part 9 for engaging a rotary tool. , the boss 7 is integrally provided,
A connecting shaft 10 is integrally provided on the other side, and the connecting shaft 10 is fitted into the boss 7, and the boss 7 and the connecting shaft 1
0, the shear pin 11 is inserted through the rotary tool engaging square shaft portion 9, so an excessive rotational force is applied to the rotary tool engaged with the rotary tool engaging square shaft portion 9 to rotate the rotary body 3 having the load sheave 2. In this case, the shear pin 11 is sheared and rotational force is not transmitted, and as a result, the traction chain 1 may be subjected to excessive tension and break, or an excessive binding force may be applied to the cargo, causing damage to the cargo. can be prevented from
Furthermore, since the shear pin 11 is a cotter pin that is normally used for machinery and appliances, it is easy to attach and remove it and replace it, and it is also easy to procure it if it is sheared.

[Brief explanation of the drawing]

The drawings show one embodiment of this invention, with FIG. 1 being a front view of the traction device and FIG. 2 being a side view thereof. Figure 3 is a longitudinal sectional front view showing the traction device main body when the cam member is rotated to the neutral position;
The figure is a vertical side view of the same, Figure 5 is a vertical front view showing the relationship between the shaft pressing spring, the square shaft of the operating shaft, and the frame, and Figure 6 is a rotating body provided with a square shaft for engaging a rotary tool. FIG. 7 is a sectional view taken along line D--D in FIG. 6. Fig. 8 is a longitudinal sectional front view showing the traction device main body when the pawl is locked in the engaged state; Fig. 9
The figure is a longitudinal side view of the central part of the load sheave part and other parts in Fig. 8, and Fig. 10 is a longitudinal side view showing the side part of the lower part and the central part of the upper part in Fig. 8 cut away. FIG. 11 is a longitudinal sectional side view showing the main body of the traction device when the claw metal fitting is locked in the detached state. In the figure, 1 is a traction chain, 2 is a load sheave, 3 is a rotating body, 4 is a frame, 5 is an engagement spring, 6 is a claw metal fitting, 7 is a boss, 8 is a shaft insertion hole, 9
10 is a connecting shaft, 11 is a shear pin, 12 is an engaging tooth, 13 is an arcuate bearing surface,
14 is a ratchet and support shaft, 15 and 16 are frame constituent units, 18 is a chain guide, 19 is a chain stripper, 20 is a semi-cylindrical portion, 26 is a rivet, 27 is a claw piece, 28 is a presser plate, 30 is a Support shaft for the pawl fitting, 32 is an operating shaft, 33 is a square shaft portion, 36 is a square shaft portion for fitting a rotary tool, 37 is a cam member for holding the pawl fitting engagement position, 38 is a cam for holding the pawl fitting detachment position. Members: 40 is a shaft presser arm, 41 is a shaft presser spring,
42 and 46 are engaging metal fittings.

Claims (1)

[Scope of utility model registration request] A rotating body 3, which includes a load sheave 2 around which a traction chain 1 is wound, and a ratchet wheel for preventing reverse rotation, is rotatably supported by a frame 4, and is supported by an engagement spring 5.
a pawl metal fitting 6 that is pressed by and engaged with the ratchet wheel;
is pivotally attached to the frame 4, a boss 7 is integrally provided on one end of the rotary body 3 and a rotating tool engaging square shaft portion 9, and a connecting shaft 10 is provided on the other. Overload prevention in a traction device characterized in that the connecting shaft 10 is fitted into a boss 7, and a shear pin 11 made of a split pin is inserted between the boss 7 and the connecting shaft 10. Device.