GB2281729A - Pivotable arm for eletric or other power supply - Google Patents

Abstract

A pivotable arm arrangement comprising: a bridge member 12 for attachment to a handle 22, 23 of a mobile machine M; an arm (27) pivotably attached at its inner end to the bridge member for rotation about a vertical pivot axis (32) over an arc extending between first and second outboard end positions 34, 35 and a lead support (29) mounted on the arm at or near the outboard end with an axis (36) parallel to the inner end axis (32) and adapted to support a lead providing a source of power to the mobile machine. Typically the mobile machine is a mower having an electrically powered motor to which electrical power is supplied by the a lead attached to the lead support. <IMAGE>

Description

ALIGNMENT DEVICE This invention relates to an alignment device. It is concerned with an alignment device for use with mobile machinery to which power is supplied by way of a floating lead.

Typical of widely used mobile machinery of this type are garden mowers though the invention is not limited to these.

Electrical power is conveniently supplied to a mobile machine by way of a floating lead. If the lead is attached to the machine at a point off-set from a central position then when the machine is moved the cable attachemnt cause a moment to act on the machine causing it to be rotated. This can be inconvenient for example in the case of a ground effect machine where the weight of the machine is supported on a continuously sustained air cushion such as a hover mower. Consider such a machine being used to follow a series of parallel paths whose mid point is substantially at right angles to the surplus lead linking the vehicle to the power source. In passing along a first such path the lead extends from one side of the machine. When turning and returning along a second path parallel to and slight overlapping with the first path the lead must be caused to extend from the other side of the machine. Consequently when the machine is turned from the end of first path and starts off down the second there is a need for the user to take positive action to avoid the lead becoming entangled with the machine and in particular to avoid the lead being cut. While this example refers to a ground effect machine it is also applicable to a vehicle supported on ground engaging wheels or rollers According to a first aspect of the present invention there is provided an alignment device comprising: a bridge member serving to provide for the attachment of the device to a mobile machine; an arm pivotably attached at one end to the bridge member for rotation about a pivot axis over an arc extending between a first outboard end to a second outboard end; and a lead support, mounted on the arm at or near the opposite end to the one end, adapted to support a lead providing a source of power to the mobile machine, any loading applied to the arm by way of the lead substantially acting on the arm on an axis parallel to the pivot axis.

According to a first preferred version of the first aspect of the present invention the bridge member incorporates two demountable attachments adapted for securing the bridge member to the mobile machine.

According to a second preferred version of the first aspect of the present invention the lead support incorporates a plug and socket providing for the lead to be be disconnected and connected at will in the vicinity of the bridge member.

According to a second aspect of the present invention there is provided a mobile machine which is adapted to receive power by way of a floating lead characterised by a device according to the first aspect or any preferred version thereof.

According to a preferred version of the second aspect of the present invention the mobile machine is adapted for movement in a forward path direction so that the first outboard end is positioned on one side of the forward path direction and the second outboard end is positioned on the opposite side of the one side of the forward path direction.

While the invention is particularly applicable to electrically powered machines it could also be used for mobile machines powered by way of a lead from other energy sources such as a compressed fluid which can transmit power to the machine by way of the lead.

An exemplary embodiment of the invention will now be described by way of the accompanying drawings of an alignment device for a lawn mower and of the use thereof of which: Figure 1 is a plan view; Figure 2 a front elevation in the direction of arrow II in Figure 1; Figures 3,4 and 5 are, respectively, a front elevation, plan view and an end view of a component of Figure 2; Figure 6 is a diagrammatic plan view of a lawn mower incorporating the alignment device when in use.

Figures 1 and 2 variously show alignment device 11 mounted on a ground effect mower M having a blade shroud M' with a normal direction of travel F as will be describer hereafter. Bridge member 12 is made up of a front beam 13 incorporating a left block 14 and a right block 15. The left block 14 is slotted to enable a first clamp 17 to be secured at a selected lateral location on the block 14 by way of a bolt 18.

Likewise the right block 15 is slotted to enable a second clamp 20 to be secured at a selected lateral location on the block 15 by way of a bolt 21. By having a range of possible positions for the first clamp 17 and the second clamp 20 the space between the clamps 17, 20 can be varied to suit the machine on which the device is to be mounted.

In this case first clamp 17 serves to secure the device 11 to left hand upright 22 of mower M. Likewise second clamp 20 secures the device 11 to right hand upright 23 of mower M. The mower M is pushed in its normally forward direction of motion F by a user grasping a handle extending between the left hand upright 22 and right hand upright 23.

Front beam 13 has at its centre an integral upper extension 24 and lower extension 25 which serve to retain inboard end 26 of arm 27 (shown separately in Figures 3, 4 and 5) whose outboard end 28 has mounted on it a cable sleeve 29 which retains a cable 30 whereby mains power is supplied to a motor powering a blade of the mower. The inboard end 26 is retained in extensions 24, 25 by pivot pin 31 to provide for pivoting of the arm 27 about axis 32 so that cable sleeve 29 can pivot over arc 33 from a first outboard position 34 as shown in Figure 1 and a second outboard position 35 shown in broken outline. The cable sleeve 29 provides for the portion of cable C within the sleeve to lie on an axis 36 which is parallel to axis 32.

An advantage in having the axis 36 of the sleeve, and so of the portion of cable C mounted within it, being disposed parallel to the pivot axis 32 lies in the ability of the cable attached to the arm 27 to sustain loading arising from the action of the cable C on the arm 27. In use a substantial main section of cable will lie on the ground between between the sleeve 29 and a power source to which the mower is connected.

There will be only a relatively short length of cable in the air up to the sleeve 29 from the main section lying on the ground. However in use as the mower is moved generally away from the power source an increasing amount of the cable on the ground will be dragged towards the mower and this can result in a substantial increase in the loading of the arm 27. By aligning the axis 36 of the sleeve 29 vertically any twisting or bending applied by the sleeve 29 to the the cable C tends to be absorbed by the cable C which readily accommodates such twisting or bending over a fair length of the cable in C the vicinity of the sleeve 29. This is to be preferred to the effect of having a sleeve mounted so as to have the sleeve axis radially perpendicular to the pivot axis 33. In this latter case a short length of cable adjacent the sleeve 29 is subject to a considerable degree of stressing which can lead to safety and maintenance problems.

Figure 6 shows the device in use. Lawn mower M having been pushed forwardly in direction F along track 41 has reached the track end at position I with arm 27 located at the first outboard position to the left (as shown in Figure 1) with cable C extending generally to the left of track 41. The mower M has now to be directed back along a track 43 over an uncut length of grass parallel to track 41. The mower M is rotated 18 in an anticlockwise direction A and displaced sideways a distance L so as to face along track 43. Through rotating the mower M anticlockwise the horizontal component of force imposed by the cable C on the arm 27 by way of sleeve 29 causes the arm 27 to be swing along arc 33 until it takes up the second outboard position 35 (Figure 1).

After the mower M has been pushed a few steps along the track 43 it arrives at position II where the relative positions of mower M, its new direction of travel F, arm 27 and cable C are shown in broken outline. It will be apparent that in changing from position I to position II the only action likely to be required by the user of the mower M is to provide for anti-clockwise rotation of the mower M and of lateral displacement prior to pushing the mower along the new track 43. Little or no hand manipulation of the cable C is required and in changing direction the arm 27 tends to automatically move so as to provide for the cable to be kept on the side of the mower M on which the main part of cable C lies. To adopt a sailing metaphor the device enables the mower M to be readily maintained to leeward of the main bulk of the cable C.

The device frees the user (particularly an infirm or uncoordinated one) from a need to manipulate the mower on changes of direction. If necessary clips can be provided on the leading side of the front beam 13 near its outer ends whereby the outboard end 28 of the arm 27 is readily retained in the first or second outboard positions to prevent the arm moving when the mower is subject to slight changes of direction. Each clip however provides for the ready release of the arm 27 from whichever extreme position it is in when a substantial change of direction is applied to the mower M.

The exemplary embodiment refes to a ground effect machine. However the invention is equally applicable to a machine making use of ground engaging wheels, rollers or skids or combinations of these.

Claims (9)

1 An alignment device comprising: a bridge member serving to provide for the attachment of the device to a mobile machine; an arm pivotably attached at one end to the bridge member for rotation about a pivot axis over an arc extending between a first outboard end to a second outboard end; and a lead support, mounted on the arm at or near the opposite end to the one end, adapted to support a lead providing a source of power to the mobile machine, any loading applied to the arm by way of the lead substantially acting on the arm on an axis parallel to the pivot axis.

2 An alignment device as claimed in Claim 1 wherein the bridge member incorporates two demountable attachments adapted for securing the bridge member to the mobile machine.

3 An alignment device as claimed in Claim 1 or Claim 2 wherein the lead support incorporates a plug and socket providing for the lead to be disconnected and connected at will in the vicinity of the bridge member.

4 A mobile machine adapted to receive power by way of a floating lead the machine being equipped with a device according to Claim 1, Claim 2 or Claim 3 whereby a floating lead can be supported in the vicinity of the machine.

5 A mobile machine as claimed in Claim 4 adapted for movement in a forward path direction so that the first outboard end is positioned on one side of the forward path direction and the second outboard end is positioned on the opposite side of the one side of the forward path direction.

6 A mobile machine as claimed in Claim 4 or Claim 5 wherein the mobile machine is powered by electricity and the lead is an electricity supply cable.

7 A mobile machine as claimed in Claim 4 or Claim 5 wherein the mobile machine is powered by a compressed fluid and the lead is a compressed fluid supply line.

8 An alignment device as herein before described with reference to Figures 2, 3,4 or 5 of the accompanying drawings.

9 A mobile machine as hereinbefore described with reference to Figures 1 and

6 of the accompanying drawings.