GB2216862A - Winches - Google Patents

Abstract

A portable rescue winch has a main winding drum (46) rotatable substantially continuously by reciprocal movement of a lever (56) so that the person being rescued is less prone to discomfort or injury. Rotation of the main drum is by means of pawls (58, 62) movable by the lever to act on a toothed wheel (54) attached to the drum. One paw (58) is directly connected to the lever and the other (62) is connected to the handle via a linkage system 66-74. Lever 56 is in two separable parts for ease of transport. Part of the drum axle (48 Fig 2 not shown) can be disconnected to allow a few turns of rope to be made directly onto the drum. Rope can be passed on to guide pulley (381 by resiliently parting over-lying arms (42). <IMAGE>

Description

Title: Winches DESCRIPTION The invention concerns winches.

Winches are often used in rescue situations and motorised winches, such as fixed to a vehicle, are available for that. However, there are many situations, particularly at cliff top or mountain rescue situations, where a vehicle cannot be used because of the terrain.

Hand operated winches are also available but these generally have a discontinuous action, which can cause discomfort and possibly further injury to a person being raised, say on a stretcher, by the winch.

Yet another disadvantage of currently available winches is that winding of a rope or wire onto the winding drum has to be commenced from one end of the rope or wire. That can cost valuable time if only a part length of the rope or wire is needed to cover the distance from the winch to the object to be lifted.

The object of this invention is to provide a winch that may overcome one or more of the above-mentioned disadvantages.

According to the invention there is provided a portable winch having a main winding drum rotatable substantially continuously by reciprocal movement of a lever.

Preferably rotation of the main drum is by means of pawls movable by the lever to act on a part of or attached to the drum, such as a toothed wheel. One pawl may be directly connected to the lever so that movement in one direction of the lever causes the pawl to action the toothed wheel to rotate the drum. A second pawl may be connected to the handle via a linkage system whereby movement of the lever in the opposite direction causes the second pawl to act on the toothed wheel to rotate the drum.

The pawls may be pivotable or spring loaded so that the wheel can pass the one pawl whilst the other pawl is acting on the wheel.

The winch of the invention preferably has a frame that is convenient for carrying on a persons back and may have legs with pointed feet for ground penetration and/or grip.

The main drum preferably has a removable axle part, whereby upon removal thereof a rope or wire can be wound around the drum at any point along its length.

The removable axle part may be screw threadedly connected to the remainder of the axle and means for preventing unscrewing thereof may be provided, such as a latch member that engages a part of the winch frame.

The intended front end of the winch may include a secondary guide wheel and a guard therefor to prevent the rope or wire escaping therefrom. The guard preferably has two parts that are normally touching but between which a rope or wire can be forced, say laterally of the intended direction of the rope or wire, so that the rope or wire cannot escape past the guard in use.

The winch of the invention may also have an anti-run device, such as a jamming cleat before or after the main drum to restrain the rope or wire in the event of slippage.

In addition a ratchet type mechanism may be included in the winch of the invention to prevent rotation of the main drum contrary to that for winding a rope or wire thereon. Such a mechanism may include a pivotable, preferably spring-loaded, pawl that abuts the toothed wheel in one direction but past which the wheel can move in the opposite direction.

The lever is operated reciprocally but in order to limit its extent of movement in either direction it may be desirable for the winch to have stops provided.

This invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side view of a winch; Figure 2 is a plan view of the winch of Figure 1; and Figure 3 is a front view of the winch of Figure 1.

Referring to the accompanying drawings, a winch 10 has a supporting frame 12. The frame 12 comprises upper frame member 14 that is generally U-shaped to provide two parallel members 16 that are angled downwards at a distance from the bend to form two front legs 18. Two rear legs 20 are joined to the upper frame member 14 just after the bend. The legs have pointed ends for ground penetration for securement.

Each pair of a front and a rear leg is connected by a lower frame member 22 and the legs of the front pair are connected by upper and lower cross members 24 and 26 and the rear pair of legs are connected by cross member 28. The upper frame members 16 are connected prior to the U-bend by a cross member 30. In addition the angles between the rear legs and the members 16 and the front legs and the members 16 are filled with plates 32 and 34 respectively. The front plates 32 support a front axle 36 that carries a pulley wheel 38 rotatably thereon. On each side of the pulley wheel 38 is a fixed collar 40, each having an upstanding L-shaped arm 42. The arms 42 face inwards so that their horizontal parts overlie each other. The arms are slightly resilient so that a rope can be forced between them onto the pulley wheel 38 but cannot escape.

The rear plates 34 support an axle 44 for a winding drum 46. On one side of the drum the axle is separable so that axle part 48 can be unscrewed from the rest of the axle and withdrawn. That is to allow several turns of a rope to be easily wound round the drum 46. The outer end of the axle part 48 has a transverse arm 50 for rotation thereof and one end of the arm 50 has a rotatable latch member 52 then can be rotated to latch over upper frame member 16 to prevent unscrewing of axle part 48.

Attached to the drum 46 on the opposite to the axle part 48 is a toothed wheel 54 which is pawl driven to rotate the drum 46. The pawl drive mechanism is operated by reciprocating movement of handle 56. The handle 56 carries a first spring loaded pawl 58 that engages a tooth of wheel 54 when the handle is moved rearwards to turn the wheel and hence the drum 46. The handle 56 is also connected by a linkage system 60 to a second spring loaded pawl 62 that engages a tooth of the wheel 54 to turn the wheel when the handle is moved forwards. When the first pawl is operating to turn the wheel 54 the second pawl is not acting against the wheel 54 and vice versa.

The linkage system 60 comprises a first bifircated link 66 fixed at an angle to the handle 56 and pivotally connected to a second link 68. The second link 68 is pivotally connected to a third bifurcate link 70 that is pivotably mounted on front axle 36 and has a depending angled position 72. That position 72 is pivotally connected to a generally horizontal linkage 74 and that is pivotally connected between parallel linkages 76 depending from the axle, the inner of which carries the second pawl 62.

A third spring loaded pawl 78 is mounted on the cross member 30 and operates in a ratchet fashion on the toothed wheel 54 to prevent rotation of the drum in a direction contrary to that imparted by the movement of the handle.

Front and rear stops 80, 82 respectively are provided to limit extent of movement of the handle.

The front stop 80 is mounted on cross member 24 and the rear stop 82 is mounted on an arm 84 extending upwards from cross member 28. At the full extent of movement of the handle the linkage system 60 will actually abut against the stops as indicated by the broken lines in Figure 1.

The winch 10 may also be provided with an anti-run device such as a jamming cleat before or after the main drum 46.

The handle 56 is in two separable parts 56A and 56B, the upper part 56A fitting telescopically into lower part 56B the two parts being held together by a pin 90. That is to facilitate transportation of the winch say as a back pack.

In use the winch will first be secured to a surface. The main axle is then split so that a rope wound several times around the drum and the axle re-connected. The rope is then passed between the arms 42 onto the pulley wheel 38.

The rope is held rearward of the winch to take up slack, whilst the other end is attached to whatever is to be raised by the winch. Reciprocal movement of the handle then turns the main drum continuously and smoothly due to the alternate actions of the first and second pawls in order to pull the rope through the winch. The generally smooth and continous rotation of the drum is particularly advantageous when the winch is being used to raise an injured person, especially one on a stretcher, in limiting jerky movement that might distress or cause further harm to that person.

An advantage arising from being able to split the axle of the main durm is that time is not wasted by -having to put a rope on from one of its ends if only a part of its length is needed. The rope can simply be wound around the drum at whatever point along its length is necessary.

The winch is capable of being carried by one person say on a back pack and so is suitable for use in situations where the terrain dictates that vehicular transport cannot be used so that a motorised winch cannot be used.

Claims (21)

1. A portable winch having a main winding drum rotatable substantially continuously by reciprocal movement of a lever.

2. A winch as claimed in claim 1, wherein rotation of the main drum is by means of pawls movable by the lever to act on a part of or attached to the drum.

3. A winch as claimed in claim 2, wherein said part is a toothed wheel.

4. A winch as claimed in claim 3 having a first pawl directly connected to the lever so that movement in one direction of the lever causes the pawl to action the toothed wheel to rotate the drum.

5. A winch as claimed in claim 3 or 4 having a second pawl connected to the handle via a linkage system whereby movement of the lever in the opposite direction causes the second pawl to act on the toothed wheel to rotate the drum.

6. A winch as claimed in claims 3, 4 or 5, wherein the pawls are pivotable or spring loaded so that the wheel can pass the one pawl whilst the other pawl is acting on the wheel.

7. A winch as claimed in any one of claims 1 to 6 having a frame that is convenient for carrying on a persons back.

8. A winch as claimed in claim 7, wherein the frame has legs with pointed feet for ground penetration and/ or grip.

9. A winch as claimed in any one of claims 1 to 9, wherein the main drum has a removable axle part, whereby upon removal thereof a rope or wire can be wound around the drum at any point along its length.

10. A winch as claimed in claim 9, wherein the removable axle part is screw threadedly connected to the remainder of the axle and means for preventing unscrewing thereof are provided.

11. A winch as claimed in claim 10, wherein the means for preventing unscrewing of the axle parts comprises a latch member that engages a part of the winch frame.

12. A winch as claimed in any one of claims 1 to 12, wherein the intended front end of the winch includes a secondary guide wheel and a guard therefor to prevent the rope or wire escaping therefrom.

13. A winch as claimed in claim 12, wherein the guard has two parts that are normally touching but between which a rope or wire can be forced so that the rope or wire cannot escape past the guard in use.

14. A winch as claimed in claim 13, wherein a rope or wire is forced between said two parts laterally of the intended direction of the rope or wire.

15. A winch as claimed in any one of claims 1 to 14 having an anti-run device before or after the main drum to restrain the rope or wire in the event of slippage.

16. A winch as claimed in claim 15, wherein said anti-run device is a jamming cleat.

17. A winch as claimed in any one of claims 1 to 16 including a ratchet mechanism for preventing rotation of the main drum contrary to that for winding a rope or wire thereon.

18. A winch as claimed in claim 17, wherein said ratchet mechanism includes a pivotable pawl that abuts the toothed wheel in one direction but past which the wheel can move in the opposite direction.

19. A winch as claimed in claim 18, wherein the pawl is spring loaded.

20. A winch as claimed in any one of claims 1 to 19 having stops to limit extent of movement of the lever in either direction.

21. A portable winch substantially as hereinbefore described with reference to and as illustrated in the accompanying drawwings.