GB2312012A - A detachable winch for a ladder - Google Patents

Abstract

A load handling device for raising and lowering loads comprises a winch assembly 8 mounted on rungs of a ladder. The loads are lifted by a line 11, strap or the like which is supported at height above the winch 8 either by passing the line 11 over a rung or by passing it over a pulley 29 which may be mounted towards the top of the ladder, supported by a pair of yoke formation wires 30. The winch assembly 8 may be mounted to any three consecutive rungs anywhere along the ladder's length. Further the winch assembly 8 may be mounted on the side of the ladder closest to a support against which the ladder leans or alternatively it may be mounted on the side of the ladder that is remote from the support.

Description

LOAD CONTROL This invention relates to the control and handling of loads and particularly to the handling of loads which, for the purposes of such handling, require to be carried by way of ladders or the like from a level located below a higher level at which it is required to position the load.

In relation to the handling of loads involving the use of ladders there is regretably frequently involved, during such handling, an element of carelessness or lack of attention to the dangers that may be involved in carrying a load up a ladder. This danger particularly arises whenever the actual handling of the load requires the use of two hands so as:- correctly to support the load; to steady the load; to provide adequate and satisfactory grip; and so forth. When such situations prevail is is not uncommon for a person to attempt to mount a ladder, even though such person does not have a hand freely available to steady and support himself and/or the load against undesired movements, with outhand holding the ladder and thereby relying solely upon a sense of balance to enable the person to mount the ladder without dropping the load or falling off the ladder.

Dangers and risks such as above indicated are enhanced when the loads are of such size, shape, dimensions etc., as to present relatively large dimensioned objects which become very susceptible to the effects of wind, particularly the effects of unexpected gusts of wind.

This particular situation arises in connection with the replacement of window frames fitted to buildings.

The replacement of window frames has developed into a large scale industrial activity and as a result working practices have developed in which the installation of window frames and the glazing therefor are carried out, often by a pair of workperson or not infrequently a lone workperson, working from a ladder or ladders.

During the replacement of windows and associated frames the common practice is to remove the originally installed windows and the associated frames required to be replaced from the associated building by whatever means considered convenient, usually one involving total distruction of the original window frame.

In a case where two operators are involved the replacement frame is them lifted from the ground by one operater who carries the frame up a ladder and when the frame is at a convenient height i.e., opposite the window frame receiving opening in a wall the thus lifted window frame is passed to the other operator. After this both operators become involved in the various steps and operations needed to mount and secure the replacement frame in a required position.

Once the frame has been satisfactorily fitted it is then necessary to mount the actual glazing to the newly fitted frame. Once again relatively large area load may need to be manhandled by any operator mounting a ladder.

With a load such as a double glazed panel of glass the risk of extremely dangerous conditions are created with respect to the working safety of the operator carrying the glazing sheet up the ladder.

Clearly, when a single operator is involved this single operator has to carry out all of the operations involved whereby the handling difficulties are increased.

It is an object of the invention to provide a method and means for facilitating the handling of loads such as above discussed under conditions where a ladder is required to be used.

Broadly, acccording to a first aspect of the invention there is provided a method of handling loads involving the use of a ladder or the like, including the steps of mounting to the ladder a winch assembly in such manner that a line, strap or the like controllable by the winch assembly can be supported at a desired lvel above the winch assembly, supporting the load from the free end of the line, strap or the like, operating the winch assembly to lift or lower a load supported by the line, strap or the like to displace the load to a desired height for subsequent handling at said desired height.

Preferably, the line is supported utilising a rung of the ladder.

In accordance with a further aspect of the invention there is provided a winch assembly adapted for readily releasable connection with a ladder.

Preferably, the winch assembly is of such construction that it is releasably mountable utilising rungs of the ladder to which it is to be mounted.

Conveniently, the winch assembly includes a first ladder engagement means readily engageable with a selected location of the ladder; a second ladder engagement means adapted for engagement with a second selected location of the ladder, the first and second means be relatively displaceable with respect to each other, and means for locking the first and second second ladder engagement means against relative separation folloowing engagement with the ladder, the arrangement being such that separation of the first ladder engagement means is simultaneously prevented from disengagement from its associated location following engagement of the second ladder engagement means with its associated location.

Preferably, the engagement means are adapted to engage with rungs of the ladder.

For a better understanding of the invention and to show how to carry the same into effect reference will now be made to the accompanying drawings in which: Figure 1 is a schematically illustrates a first stage in the mounting of the winch assembly to a ladder; Figure 2 is a schematic view of the assembly of Figure 1, and illustrating a later stage in the mounting of the winch assembly to the ladder; Figure 3 is a schematic view of the assembly of Figures 1 and 2, and illustrating a final stage in the mounting of the winch assembly to the ladder; Figure 4 is a schematic view of the assembly of Figures 1 and 2, and illustrating an possible alternative mode of mounting the winch device of the invention to a ladder; Figure 5 schematically illustrates a first mode of using the ladder and winch assembly combination shown in Figures 1 to 4; Figure 6 schematically illustrates a second mode of using the ladder and winch assembly combination shown in Figures 1 to 4; Figure 7 schematically illustrates a further mode of using the ladder and winch assembly combination shown in Figures 1 to 4; and Figure 8 schematically illustrates a still further mode of using the ladder and winch assembly combination shown in Figures 1 to 4; Referring now to the drawings and more particularly to Figure 1 a fragmentary portion of a ladder 1 including two sections 2 and 3 each including conventional side rails 4 and 5 and regularly spaced rungs 6. As shown the two sections 2 and 3 overlap at the region 7. A winch assembly 8 in accordance with the invention is intended to be securely mounted to the rungs 6 of the ladder 1 as is indicated in the Figure.

The winch assembly 8 includes a main frame or housing 9 carrying a drum 10 for a line, strap or the like 11 which is feedable from the drum 10 or retrievable back onto the drum by rotation of a control handle 12. It will be appreciated that suitable clutch/reversing means (not separately shown) are provided to enable drum rotational drive in both operational rotational directions thereof by the operating handle 12. A gear box or other drive arrangement, schematically indicated at 13 is provided, the gear box incorporating gearing drive ratios as thought necessary for the required purposes.

The winch assembly 8 includes a ladder mounting unit 14 including a plate formation 15 which allows it to bear against at least three adjacent rungs 6. A first ladder rung engaging part in the form of a U-shaped channel member 16 is provided at the lower end region of the plate formation 15. The member 16 is adapted for engagement with a lower one of said three rungs, shown in the Figure as rung 6A, by a downward movement from the upperside of the rung 6A. The shaping and dimensioning of the channel member 16 is such that when engaged with a rung 6A it can only be released from the rung 6A by bodily displacement of the winch assembly 8 in the opposite direction to that involved in the engagement process.

A second ladder rung engaging member 17 operationally facing in the opposite sense to that of the member 16 is provided upon on or as part of an elongate plate 18 that is adapted for lengthwise slidable engagement with the plate formation 15. The interconnection between the formation 15 and the plate 18 is such that the plate 18 can only move lengthwise of the plate formation 15 and cannot otherwise disengage therefrom. The interconnection between the plates is indicated by the engagement of side rails 19 on the plate 18 telescopically engaging with corresponding side rails 20 provided on the plate formation 15.

An elongate slot 21 is provided in the plate formation 15.

The slot 21 is intended to be engaged by a bolt or the like 22 projecting from the plate 18 whereby by means of a locking means i.e., a nut 23, the plate 18 and the plate formation 15 can be very securely locked against relative movement. Other convenient forms of locking means can be used.

The second rung engaging member 17 is intended to be operationally engageable with a a second rung 6B which is spaced from the rung 6A in the upwards direction of the associated ladder section 2.

As will be appreciated the second rung engaging member is adapted to engage with the aforesaid lower rung 6B by displacement thereof in a direction opposite to the rung engaging direction of the other engagement member 16.

To mount the winch assembly as so far discussed the lower hook member 16 is engaged over the rung 6A and pushed downwardly so that the member beds firmly against the rung. This operation is indicated in the Figure 1.

After this, the plate formation 15 is moved to the position in which the member 18 can be caused to engage with the upper rung 6B by displacing the plate 18 upwardly in the opposite direction to the engaging movement direction of the hook member with the lower rung 6A.

Once the hook member 18 has been engaged with the upper rung 6B the lock nut 23 is tightened so as to prevent relative longitudinal movement between the plate formation 15 and the plate 18. Once this has been effected the winch assembly 8 is firmly secured to the ladder.

As so far described it will be noted that the mounting strength of the winch assembly 8 with respect to the ladder rails 5 relies totally upon the strength of the attachment of the rung 6A to the ladder rails 5 and the resistance to bending of the rungs. In order to avoid such total reliance in the case of ladders having a hollow rung structure an elongate pin 25 is engaged with the interior of the rung 6A, the pin 25 being held in place by a locking pin 25A (Figure 2) Referring now specifically to Figure 3 which illustrates a ladder 1 to which the winch assembly of the invention has been mounted. At the upper end region of the ladder a pulley is supported to a convenient upper level rung 6C by engaging a pin 27 through the rung (similarly to the pin associated with rung 6A, this pin 27 being of such length as to project outwardly from the ends of the rung 6C to provide projections 28. A pulley 29 is supported from the projections by a pair of yoke formation wires 30.

The line 11 is engaged over the pulley 29 as shown in Figure 3. The free end of the line is connected with means 31 which facilitates the connection of the load to be lifted or lowered by the winch assembly of the invention.

An alternative mode of engaging the winch assembly 8 with the ladder 1 is shown in Figure 4. In this mode the winch device is mounted to the side of the ladder adjacent to the wall or other support (not shown) against which the ladder rests.

In addition, it will be noted that the free end of the line, strap or the like 11 is caused directly to to over hang the upper rung 6C of the ladder as is indicated in Figure 4. Since with this possibility relative movement is required, when the winch assembly of the invention is in use, a plastics or other suitable material sleeve (not shown) is provided on the upper rung 6C of the outer section of the ladder to prevent the loading movements of the line, strap, or the like from damaging the rung 6C.

As will be seen from Figure 3, the free end 24 of the line, strap or the like hangs freely vertically to the winch side of the ladder.

It will be undrstood that the pin and yoke arrangement can also be adopted for use with the winch assembly location shown in Figure 4.

Various possibilities for the use of the ladder and winch combination so far discussed are shown in the Figures 4 to 7.

Referring now to Figure 5 in this Figure the ladder 1 is shown resting against the wall 32 of a building (in the Figure only a fragmentary part of the wall 25 and the roof 33 of the building are shown). A window opening 34 is represented by a rectangle.

As shown the ladder sections 2 and 3 are relatively extended so that the uppermost rung 6C is located above the window opening 34 to such extent that the pulley 29 over which the line, strap, or the like 11 travels is positioned above the highest level it is required to lift the uppermost part of the load 36, the latter being shown as a window frame in the Figure 5.

After so positioning the ladder 1 the window frame 36 is secured to the free end 31 of the line, strap or the like 11 and the winch assembly 8 is operated to raise the window frame 36 to the required position with respect to the window opening 34.

The Figure 5 illustrates the load 36 in a partially raised position.

Referring now to Figure 6 this illustrates the mode of using the winch assembly as positioned in Figure 4 but utilising the yoke 28 and pulley 29 arrangement shown in Figure 3 and involving movement of the load 36 lengthwise of the ladder. In this mode of use the load 36 lies against and is partially supported by the side rails 4 and 5 of the ladder, such that the ladder side rails 5 provide slides for the load 36.

With this arrangement the free end of the line passes down the outwardly facing side of the ladder. This mode of use is normally advocated when the soffits of the building are low and it is not possible to set the ladder as shown in Figure 5.

The Figure 6 illustrates use of the winch assembly on the side of the ladder nearest to the wall 32 and a position when the load 36, i.e., window frame is part way up the ladder 1. With this arrangement once the upper part of the load has reached the lower regions of the window opening 27 the window frame can be manhandled into position in the normal manner.

Figure 7 illustrates the case where it is desired to be able to lift loads above the gutters level 37 of a building. As will be seen the ladder is provided with a so-called ladder stand-off bracket 38 which holds the upper end of the ladder 1 away from contact with the gutters thereby enabling a load 36 to be advanced past the gutters by the mode of ladder and winch assembly combination usage shown in Figure 6.

In the case of very wide loads it is possible to use two ladder and winch assembly combinations in side-by-side configuration. This is shown in Figure 8. As will be noted the mode of combination use is that of Figure 5.

It will be appreciated the Figure 6 or 7 mode of use can by used with double ladder and winch assembly combinations where considered more appropriate.

Claims (1)

1 A method of handling loads involving the use of a ladder or the like, including the steps of mounting to the ladder a winch assembly in such manner that a line, strip or the like controllable by the winch assembly can be supported at a desired level above the winch assembly, supporting the load from the free end of the line, strap or the like, operating the winch assembly to lift or lower a load supported by the line, strap or the like to displace the load to a desired height for subsequent handling at said desired height.

2. A method as claimed in claim 1 and in which the line is supported utilising a rung of the ladder.

3. A method as claimed in claim 1 or 2, and in which the winch assembly is mounted to that side of a ladder that is remote from a support against which the ladder leans.

5. A method as claimed in claim 1 or 2, and in which the winch assembly is mounted to that side of a ladder that is adjacent to a support against which the ladder leans.

6. A method aa claimed in claim 1,2,3,4 or 5, and in which the line of the winch assembly cooperates with a pulley that is suspended from a location above a height it is desired to raise the load with the winch assembly.

7. A method as claimed in any one of the preceding claims and including the step of using two winch assemblies and associated ladders in side by side relationship to permit both winch assembly to be utilised for handling a common load.

8. A method of handling loads involving the use of a ladder substantially as hereinbefore described with reference to the accompanying drawings.

9. A load handing arrangement including winch assembly adapted for readily releasable connection with a ladder.

10. A load handling arrangement as claimed in claim 9, and wherein the winch assembly is of such construction that it is releasably mountable by utilising rungs of the ladder to which it is to be mounted.

11. A load handling arrangement as claimed in claim 9 or 10, and including a first ladder engagement means adapted for engagement with a selected location of the ladder; a second ladder engagement means adapted for engagement with a second selected location of the ladder, the first and second ladder engagement means being relatively displaceable with respect to each other, and means for locking the first and second ladder engagement means against relative separation following their engagement with the ladder, the arrangement being such that separation of the first ladder engagement means is prevented from disengagement from its associated location following engagement of the second ladder engagement means with its associated location.

12. A load handling arrangement as claimed in claim 11, and wherein the second ladder engagement means is positionally displaceable with respect to the first engagement means.

13. A load handling arrangement winch as claimed in claim 11, and wherein the first and second ladder engagement means engagement means are adapted to engage with rungs of the ladder.

14. A load handling arrangement as claimed in any one of claims 9,10,11,12 or 13, and wherein a pulley supportable from the ladder at a location above the location of attachment of the winch assembly to the ladder is utilised to facilitate displacement of the load supporting line of the winch assembly during the use thereof.

15 A load handling arrangement control constructed and arranged to operate substantially as hereinbefore described with reference to Figures 1,2 and 3; Figures 1,2,3,and 4; or Figures 5,6,7 or 8 in conjuction with Figures 1,2,3 and 4 of the accompanying drawings.