GB2482715A

GB2482715A - Power tool comprising gear that may be disengaged from gear drive to allow free rotation of bit

Info

Publication number: GB2482715A
Application number: GB1013555.6A
Authority: GB
Inventors: Dennis Taylor; Michael D Slack
Original assignee: MARINEQUIP CORP Ltd
Current assignee: MARINEQUIP CORP Ltd
Priority date: 2010-08-12
Filing date: 2010-08-12
Publication date: 2012-02-15
Also published as: WO2012020266A1; GB201013555D0

Abstract

A portable power tool 1 comprises a bit that is rotatably driven by a motor 4, wherein the bit is connected to a gear 5 that is arranged such that it may be engaged with a geared drive 7 to provide drive to the bit from the motor 4, and may be disengaged from the geared drive 7 to allow for free rotation of the bit. The gear 5 may be brought into and out of engagement with the drive 7 by a pivotal movement of the gear 5. The gear 5 may comprise a worm wheel, and the drive 7 may comprise a worm gear. Two axially aligned bits may be provided, and these may face in opposite directions. The bit may comprise a crank head for engaging a crank head socket of a winch. A power tool comprising a bit that is connected to a drive shaft, wherein the drive shaft is provided with a worm wheel that is driven by a worm gear is also claimed.

Description

The present invention relates to a tool. More particularly, it relates to a portable powered tool, which allows for the engagement and disengagement of drive to a bit.

Sailing boats are generally provided with a number of manually operated winches that are used to pull in (wind up) or let out (wind out) or otherwise adjust the tension of various ropes that are connected to the sail(s). These winches each comprise a drum, on which rope is wound, and a socket, arranged to receive the head of a crank for turning the winch. Typically a handheld manual right angled crank is used.

During a sailing trip, the winches will require frequent adjustment. Such activity using only manual cranking can often involve a huge amount of effort, often more than is comfortable for older and younger family members. It is important that all members of the family, and hence the crew, enjoy their participation in the sailing trip.

Whilst some powered solutions are known, which are arranged to reduce the physical effort involved in winching, these are generally not satisfactory. Among the shortcomings of these devices are a lack of power and an inability to allow for fine adjustments (fine trimming").

The present invention arose, principally, in an attempt to provide an improved device for operating winches. Other uses will, however, be readily appreciated.

According to the present invention according to a first aspect, there is provided a portable powered tool comprising a bit that is rotatably driven by a motor, wherein the bit is connected to a gear that is arranged such that it may be engaged with a geared drive to provide drive to the bit from the motor, and may be disengaged from the geared drive to allow for free rotation of the bit.

The connection of the bit to the gear may be any connection by which rotation of the gear results in rotation of the bit. The connection may be direct or indirect. By direct it is meant that the bit is fixed relative to the gear such that rotation of the gear results in rotation of the bit, i.e. without any intermediate drive means.

Preferably, the gear is arranged such that its position may be changed relative to the geared drive, so that engagement and disengagement is achieved by moving the gear into and out of engagement with the geared drive. Most preferably, the gear is arranged to be brought into and out of engagement with the geared drive by pivotal movement of the gear relative to the geared drive. The gear may be pivoted relative to the geared drive about an axis that is parallel to an axis about which the bit rotates.

By providing a powered tool in which drive may be disengaged, it becomes possible to allow for manual operation of the tool, which is of particular use for making fine adjustments. Where this disengagement is by virtue of a pivoting action, a convenient ratcheting mechanism is facilitated.

Means may be provided for limiting the degree of pivotal movement of the gear relative to the geared drive in a direction away from the geared drive. That is for limiting the degree of pivotal movement of the gear and geared drive away from one another.

With the pivoting movement limited in a direction away from the geared drive, the ratcheting mechanism is improved, since the pivoting action may result in rotation of the geared drive about the axis of the gear.

Means may be provided for limiting the degree of pivotal movement of the gear relative to the geared drive in a direction towards the geared drive. That is for limiting the degree of pivotal movement of the gear and geared drive towards one another.

With the pivoting movement limited in a direction towards the geared drive, the risk of damage to the gear and/or geared drive by a collision of the gear with the geared drive may be effectively prevented.

The means for limiting the degree of pivotal movement may comprise a stop, or a pair of stops, against which a housing of the geared drive abuts to limit movement.

The tool preferably comprises a body and a head, wherein the gear is mounted in the head and the geared drive is mounted in the body, and the head is pivotally mounted to the body. Most preferably, the body comprises a longitudinally extending handle. The head may pivot about an axis that is perpendicular to the longitudinal axis of the handle and parallel to the axis about which the bit rotates.

By the pivotal mounting of the head to the body, a tool is provided that is well suited to ratcheting. A longitudinally extending handle is useful both when ratcheting (when the drive is disengaged) and when drive in engaged. During engagement of drive, a large turning moment can be applied against the turning force of the motor by virtue of the longitudinally extending handle.

Preferably a lock is provided, which is arranged to prevent pivotal movement of the gear relative to the geared drive when the gear is in engagement with the geared drive.

With such a locking mechanism there is no risk of an undesired disengagement of drive. The locking mechanism will act to prevent pivotal movement of the head and the body when these are arranged to pivot relative to one another. The locking mechanism may be integrated into the means for limiting the degree of pivotal movement of the gear relative to the geared drive in a direction away from the geared drive, particularly when this is provided as a stop, as described above.

The gear preferably comprises a worm wheel and the geared drive comprises a Such a drive mechanism is particularly preferable, since it allows for the provision of a drive that has low speed and high torque, which is desirable when the tool is arranged to operate winches on a boat.

Preferably, the geared drive is arranged to drive the bit in forward and reverse directions.

Preferably, two axially aligned bits are provided, which are arranged to face in opposite directions.

By such an arrangement, a simplified mechanism may be provided to allow for ratcheting in forward and reverse directions.

Preferably, the geared drive is arranged to rotate the bit at a speed of between 50 to 150rpm. Preferably, the geared drive is arranged to provide a torque of at least lOONm.

Most preferably, a torque of at least l5ONm.

Preferably, the, or each, bit comprises a crank head arranged to engage a crank head receiving socket of a winch.

Preferably, the, or each, bit is connected directly to a drive shaft, i.e. without use of an intervening chuck. Most preferably such connection is by a screw or by a pin.

By such arrangement, there is no chuck used and the bit may, in effect, comprise a combined chuck and bit, wherein the bit may be formed from a soft metal (a metal (for example, aluminium) which is softer than the metal (usually stainless steel) from which winches are manufactured). This is particularly advantageous, since the risk of damage to a relatively expensive winch by use of the tool may be significantly reduced.

The bit is most preferably, formed from a single piece of material, such that there are no joins.

Preferably, the gear is fixed to the drive shaft.

According to the present invention in a further aspect, there is provided a portable powered tool comprising a bit that is connected to a drive shaft, wherein the drive shaft is provided with a worm wheel that is driven directly by a worm gear.

Preferably, the worm wheel is arranged to be brought into and out of engagement with the worm gear by pivotal movement of the worm wheel relative to the worm wheel.

Preferably, means are provided for limiting the degree of pivotal movement of the worm wheel relative to the worm gear in a direction away from the worm gear and/or in a direction towards the worm gear.

Preferably, the bit is connected directly to the drive shaft.

Preferably, there are two bits provided, the bits being directly connected to opposed ends of the drive shaft to face in opposite directions.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a partial sectional view of a tool according to the present invention.

Referring to Figure 1, there is shown a portable powered tool 1. The tool comprises, generally, a head 2 and a body 3.

A bit (not shown) is rotatably mounted to the head 2 and is driven by a motor 4, which is housed in the body 3. The bit is a crank head, arranged to engage a crank head receiving socket of a winch. Drive is transmitted to the bit from the motor 4 through a gearbox 9, a gear 7 of a geared drive, and a gear 5. The gear 5 is a worm wheel and the gear 7 is a worm gear (endless screw).

The head 2 is pivotally mounted to the body 3 at a pivot point 8. By pivotal movement of the head 2 relative to the body 3, about the pivot point, the worm wheel 5 may be brought into and out of direct engagement with the worm gear 7.

The worm wheel 5 is fixed to a drive shaft (not shown), which is mounted to the head 2 via a bearing (not shown) so that it may rotate relative to the head 2. The crank head is mounted directly to an end of the drive shaft and is fixed thereto using a screw or a pin. The drive shaft and worm wheel 5 share a common axis, which is shown in Figure 1, and which lies parallel to the pivot axis 8. The arrangement is such that rotary motion applied to the worm wheel 5 by the worm gear 7 is transmitted directly to the crank head (through the drive shaft), the bit and worm wheel 5 turning in synchronism.

Preferably, a further crank head is provided, which is fixed to the other end of the drive shaft, such that the bits face outwardly in opposed directions.

The, or each, crank head is substantially cylindrical and comprises eight longitudinally extending ribs, which are equally spaced about the periphery of the crank head. The ribs each have a triangular profile when viewed in the axial direction. A front face of each of the ribs may be tapered. The crank head is arranged to conform to the shape of a crank head receiving socket of a winch to be turned, with the ribs arranged to engage corresponding triangular grooves provided in the crank head receiving socket.

The body 3 comprises a handle 6a and a geared drive housing 6b. These are both substantially hollow longitudinally extending elements, which are substantially tubular in form, although may take alternative forms, as will be readily appreciated. The handle and the geared drive housing are co-axial and extend along a longitudinal axis L of the tool.

The handle 6a houses the motor 4, the gearbox 9 and associated workings. The gearbox is a conventional 2-speed (high-speed/low-speed) gearbox, as will be well known to those skilled in the art.

The base of the handle 6a is provided with attachment means for removably attaching a conventional rechargeable battery to the base. The attachment means includes both mechanical and electrical connections.

On the surface of the handle 6a control switches (not shown) are provided for setting a rotation speed and rotation direction. An analogue trigger is provided to control motor speed, a direction switch is provided to allow for forward, reverse or neutral drive from the motor, and a switch is provided to switch the gearbox between the high and low speed settings.

The geared drive housing 6b extends from an upper surface of the handle 6a and houses the worm gear 7. The worm gear 7 is rotatably mounted via bearings 11 and features a downwardly extending shaft 13 that is fixed to a coupling element 17 by a pin 15.

The coupling element 17 is in turn connected to the gearbox 9. Drive is transmitted to the worm gear 5 from the gearbox 9 through this coupling. A cutout 19 is provided in the wall of the geared drive housing 6b so that the worm wheel 5 may be brought into engagement with the worm gear 7. At the top end of the geared drive housing a through hole is provided, which lies on the longitudinal axis L but extends perpendicular thereto. The through hole rotatably receives a pin 8 that is fixed to the head 2. It is by this connection that the head 2 pivots relative to the body 3 and the worm wheel 5 is brought into and out of engagement with the worm gear 7.

The drive mechanism of the tool, comprising the motor 4, the gearbox 9, the geared drive (including the worm gear 7), and the gear 5 is configured to allow rotation of the bit at a maximum of 150rpm with the gearbox set in the high speed mode and a maximum of 50rpm with the gearbox set in the low speed mode, wherein the speeds in the high and low speed modes are variable up to the maximum speeds by virtue of the analogue trigger. The maximum torque generated is at least lOONm, most preferably at least l5ONm.

To limit the pivotal movement of the worm wheel relative to the worm gear in a direction towards the worm gear, a stop 20 is provided. This stop comprises an annular boss 20 that is internal to the head 2 and is sized and located so that when the worm wheel is pivoted towards the worm gear 7 (i.e. pivoted clockwise about pivot point 8 as viewed in Figure 1) to bring the worm wheel 5 into engagement with the worm gear 7, at the point of suitable engagement of the worm gear 7 with the worm wheel 5, the boss 20 abuts the outer surface of the geared drive housing to prevent further pivotal movement in that direction.

To both lock the worm wheel 5 in engagement with the worm gear 7 and to limit pivotal movement of the worm wheel 5 in a direction away from the worm gear 7 (i.e. pivotal movement anti-clockwise about pivot point 8 as viewed in Figure 1), a lock 21 is provided. The lock 21 is attached to the head 2 and comprises a rotatable rod that extends along an axis parallel to the pivot axis 8 and to the axis of the drive shaft. The rod is cylindrical with a flat face 21a. As shown in Figure 1, when the rod is rotated so that the flat face 21a lies other than parallel and adjacent to an outer surface of the geared drive housing, then the lock 21 and the boss 20 abut opposed sides of the geared drive housing, trapping the geared drive housing therebetween and preventing pivotal movement of the head 2 relative to the body 3. The lock 21 is provided with a detent mechanism such that it has at least two defined positions, these being the locked position (as shown in Figure 1) and the unlocked position. A lever, or similar, is provided to allow the lock 21 to be rotated between the locked and unlocked positions. In the unlocked position, with the flat face 21a adjacent and parallel to the outer surface of the geared drive housing, there is a gap provided between the lock 21 and the outer surface of the geared drive housing 6b (since the rod forming the lock has a reduced diameter across the diameter perpendicular to the flat face) and the head 2 may pivot relative to the body 3 to disengage drive to the worm wheel 5 from the worm gear 7, and thereby disengage drive to the crank head.

Operation of the tool will now be described: Powered mode: The tool 1 is shown in powered mode in Figure 1, wherein the worm wheel 5 is locked in engagement with the worm gear 7 with pivotal movement prevented by the abutment of the boss 20 and the lock 21 against opposed sides of the geared drive housing 6b.

Power from the motor 4 is transmitted to the bit with the speed and direction of rotation fully controllable.

Crank mode: There may be times when, having turned a winch using the powered mode (or otherwise), it is desired to make fine adjustments ("fine trimming"). It is here that the crank mode is of great use.

When the lock is in the unlocked position, the head may be pivoted relative to the body, within predefined limits.

A user may start cranking by removing power to the motor 4. With power removed, the worm gear 7 and the worm wheel 5 are fixed in position and meshed with one another.

Next the lock 21 is rotated to the unlocked position. The body 3 may then be rotated, relative to the head 2, about the pivot point 8. With such rotation, the worm wheel 5 and worm gear 7 are disengaged from one another. When disengaged, the worm wheel 5 may rotate freely relative to the head 3. Continued rotation of the body 3 about the pivot point 8 will result in the geared drive housing 6b abutting the lock 21 and thus results in rotation of the head 2 and body 3 together about the axis of the worm wheel 5, wherein the crank head is prevented from rotation by engagement with a crank head receiving socket of a winch. Having rotated the head 2 and body 3 together about the axis of the worm wheel 5 by a desired amount (and thereby rotated the worm gear 7 about the worm wheel 5), the body 3 may be rotated back, relative to the head 2, about the pivot point 8 in the opposite direction, in order to re-engage the worm gear 7 with the worm wheel 5. With the re-engagement, and a continued turning force applied, a manual turning force may be applied to the worm wheel 5 and thereby to the crank head. The operation may be repeated as desired and provides a useful cranking action.

As and when powered drive is required, the user may lock the worm wheel 5 and As mentioned, opposed crank heads may be provided. By the provision of opposed crank heads, a winch may be cranked in two directions to pull in (wind up) or let out (wind Out) a rope, or similar. The appropriate one of the crank heads being selected in dependence on the desired cranking direction.

It will be readily appreciated by those skilled in the art that various alterations and modifications may be made within the scope of the claims.

In particular, whilst the described embodiment comprises a winch, the present invention is not limited thereto and may find application in various alternative applications, by changing the bit from a crank head to a bit that is suited to any alternative scenario. For example, in place of a crank head, the bit may comprise a lock key, for powered operation of a waterway lock, which comprises a square socket of the correct size to fit onto the spindle protruding from lock winding gear. Further uses will be readily appreciated.

Claims

Claims 1. A portable powered tool comprising a bit that is rotatably driven by a motor, wherein the bit is connected to a gear that is arranged such that it may be engaged with a geared drive to provide drive to the bit from the motor, and may be disengaged from the geared drive to allow for free rotation of the bit.
2. A tool as claimed in Claim 1, wherein the gear is arranged such that its position may be changed relative to the geared drive, so that engagement and disengagement is achieved by moving the gear into and out of engagement with the geared drive.
3. A tool as claimed in Claim 1 or 2, wherein the gear is arranged to be brought into and Out of engagement with the geared drive by pivotal movement of the gear relative to the geared drive.
4. A tool as claimed in Claim 3,. wherein means are provided for limiting the degree of pivotal movement of the gear relative to the geared drive in a direction away from the geared drive.
5. A tool as claimed in Claim 4, wherein means are provided for limiting the degree of pivotal movement of the gear relative to the geared drive in a direction towards the geared drive.
6. A tool as claimed in Claim 4 or 5, wherein the means comprises a stop, or a pair of stops, against which a housing of the geared drive abuts to limit movement.
7. A tool as claimed in any preceding claim, comprising a body and a head, wherein the gear is mounted in the head and the geared drive is mounted in the body, and the head is pivotally mounted to the body.
8. A tool as claimed in Claim 7, wherein the body comprises a longitudinally extending handle.
9. A tool as claimed in any of Claims 3 to 8, wherein a lock is provided, which is arranged to prevent pivotal movement of the gear relative to the geared drive when the gear is in engagement with the geared drive.
10. A tool as claimed in any preceding claim, wherein the gear comprises a worm wheel and the geared drive comprises a worm gear.
11. A tool as claimed in any preceding claim, wherein the geared drive is arranged to drive the bit in forward and reverse directions.
12. A tool as claimed in any preceding claim, wherein two axially aligned bits are provided, which are arranged to face in opposite directions.
13. A tool as claimed in any preceding claim, wherein the geared drive is arranged to rotate the bit at a speed of between 50 to 150rpm.
14. A tool as claimed in any preceding claim, wherein the geared drive is arranged to provide a torque of at least lOONm.
15. A tool as claimed in any preceding claim, wherein the geared drive is arranged to provide a torque of at least l5ONm.
16. A tool as claimed in any preceding claim, wherein the, or each, bit comprises a crank head arranged for engaging a crank head receiving socket of a winch.
17. A tool as claimed in any preceding claim, wherein the, or each, bit is connected directly to a drive shaft.
18. A tool as claimed in Claim 17, wherein the, or each, bit is connected to the drive shaft by a screw or by a pin.
19. A tool as claimed in Claim 17 or 18, wherein the, or each, bit is formed from a soft metal.
20. A tool as claimed in any of Claims 17 to 19, wherein the gear is fixed to the drive shaft.
21. A portable powered tool comprising a bit that is connected to a drive shaft, wherein the drive shaft is provided with a worm wheel that is driven directly by a worm gear.
22. A tool as claimed in Claim 21, wherein the worm wheel is arranged to be brought into and out of engagement with the worm gear by pivotal movement of the worm wheel relative to the geared drive.
23. A tool as claimed in Claim 22, wherein means are provided for limiting the degree of pivotal movement of the worm wheel relative to the worm gear in a direction away from the worm gear and/or in a direction towards the worm gear.
24. A tool as claimed in any of Claims 21 to 23, wherein the bit is connected directly to the drive shaft.
25. A tool as claimed in any of Claims 21 to 24, wherein there are two bits provided, the bits being directly connected to opposed ends of the drive shaft to face in opposite directions.
26. A tool as claimed in any of Claims 21 to 25, wherein the, or each, bit comprises a crank head arranged for engaging a crank head receiving socket of a winch.
27. A portable powered tool as hereinbefore described with reference to, and/or as illustrated by, the accompanying drawings.