GB2460481A

GB2460481A - Hand tool rotatable about first and second axes

Info

Publication number: GB2460481A
Application number: GB0821888A
Authority: GB
Inventors: Christopher Mark Grundy
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-05-28
Filing date: 2008-12-02
Publication date: 2009-12-02
Also published as: GB0821888D0; GB0809647D0

Abstract

A hand tool, such as a ratchet wrench, has a first mode of operation, in which rotational movement of a handle about a first axis is arranged to cause a tool to rotate about the first axis; and a second mode of operation, in which an operative member is able to be rotated about a second axis in a first multiplying region to cause the tool station to rotate about the first axis in a second multiplying region. The first multiplying region may comprise a planetary gear arrangement with planet gears 4; and the second multiplying region may comprise a bevel gear arrangement 8, 9. The second axis extends in a different direction to the first axis, and preferably extends through it. Preferably, the tool comprises a body (1, fig 1), a revolving handle 2 and a conventional handle (3, fig 1). The revolving handle may be rotatable about a longitudinal axis (A, fig 1) of the body to drive an output shaft 5, which in turn drives a ratchet wheel 10.

Description

HAND TOOL

The present invention relates to hand tools and to ratchet mechanisms for use with hand tools.

Hand tools in the form of ratchet wrenches are very well known. They come in a variety of styles and sizes, and are used to tighten and remove fasteners, such as nuts, bolts and screws.

In use, a ratchet mechanism of the ratchet wrench allows a user to tighten or remove the fasteners conveniently, by allowing a user to operate the wrench in a manner in which the fastener can be removed without the need to reposition the tool after each rotation. Usually, the wrench incorporates a mechanical switch, which is used to set the wrench for either clockwise or anti-clockwise operation.

However, ratchet wrenches suffer from the disadvantage that when the fastener is loosened it requires only a small amount of effort to rotate. This effort or torque is sometimes insufficient to trigger the ratchet mechanism. This leads to either a drive member engaged with the fastener being held by a user in order to trigger the ratchet mechanism or the user abandoning the ratchet wrench in order to remove the fastener by hand.

A further problem arises when using the wrench in a confined area. As it is necessary to rotate the wrench about the fastener, there may not be sufficient room to achieve this. This is because the handle or body of the wrench may fowl against neighbouring elements.

In the prior art, various attempts have been made to overcome the above-mentioned problems. A common theme is the use of a drive shaft extending through the body of the wrench. A bevel gear type arrangement is then used to connect the shaft to the ratchet mechanism.

For example, in US 5,058,463, a ratchet wrench that employs a rotating handle connected directly to a shaft, which extends through the body of the wrench is disclosed. The shaft is connected to the ratchet mechanism using a bevel gear type arrangement.

In another example, US 6,311,584, a ratchet mechanism is disclosed which features a folding handle extension connected to the shaft, which is rotated transversely relative to the shaft to rotate the bevel gear type arrangement of the shaft to rotate the ratchet mechanism.

Whilst these documents may describe ratchet wrenches that go some way to overcoming the problems associated with the loss of torque or the fowling against neighbouring elements, they in turn introduce additional problems. Looking at US 5,058,463, one such problem is that the shaft is connected to the rotation mechanism with a low ratio bevel gear type arrangement, which causes several rotations of the handle to be required to drive the ratchet mechanism to loosen the nut or bolt. This is slow and time consuming for the operator.

The extending handle arrangement of US 6,311,584 is more purposeful, in that the additional drive mechanism can be turned at greater speed. However, the extending handle is awkward to use and would not overcome the problems of fowling on neighbouring elements. In fact, the extending handle would worsen the situation in certain circumstances.

Further to this, all of these arrangements suffer from the disadvantage that operation of the additional driving mechanism requires the use of both hands. A hand is required to support the wrench, whilst the other hand rotates the driving mechanism. This presents difficulties.

For example, if a nut and bolt is to be removed, it is necessary to employ a second tool such as a spanner to hold the nut, whilst the bolt is rotated using the wrench.

The present invention is defined in the claims and elsewhere in this document.

There may be provided a hand tool and a ratchet mechanism.

According to another aspect of the present invention there is provided a ratchet wrench, combined with an additional mechanism for driving the ratchet mechanism. This may be in the form of a revolving handle that is constructed into the body of the tool. The revolving handle forms the annulus gear or input to a planetary gear set. By revolving the handle, drive is transferred to the planet gear, which in turn transfers drive to the sun gear or output from the planetary gear set. The sun gear may be connected to a shaft which then extends drive through the body of the tool to a bevel gear set, which is arranged throughout the ratchet mechanism. The gear ratios for the planetary gear set may be selected to produce a multiplying effect and the resolution of the final drive member is greater than the input resolution made by turning the revolving handle. Thus, the "speed brace" function of the additional driving mechanism is achieved. The revolving handle is positioned in the body of the tool in a manner to enable "single handed" operation of the wrench and additional driving mechanism.

According to a further aspect of the present invention, there is provided a hand tool. The hand tool may have a first mode of operation in which rotational movement of a handle about a first axis is arranged to cause a tool station to rotate about the first axis. The hand tool may also have a second mode of operation in which an operative member is able to be rotated about a second axis to cause the tool station to rotate about the first axis. In this case, the second axis may extend in a different direction to the first axis, with the operative member being rotatable about the handle at the location between the handle and the tool station.

Suitably, one rotation of the operative member may cause more than one rotation of the tool station.

According to a still further aspect of the present invention there is provided a hand tool having a first mode of operation in which rotational movement of a handle about a first axis is arranged to cause a tool station to rotate about the first axis. Also, the hand tool may have a second mode of operation in which an operative member is able to be rotated about a second axis in a first multiplying region to cause the tool station to rotate about the first axis in a second multiplying region, the second axis extending in a different direction to the first axis.

The operative member may have a rotation multiplying effect.

The operative member may be arranged to cause more than one rotation of the tool station.

For example, one rotation of the operative member may cause 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 rotations of the tool station.

Alternatively, one rotation of the operative may be arranged to cause less than or equal to one rotation of the tool station. For example, one rotation of the operative member may cause 0.5, 0.67, 0.83 or 1 rotations of the tool station.

In the hand tool, the first axis may extend through the second axis. The second axis may be arranged to rotate about a radius of the first axis and is arranged to move when the handle is moved about the first axis.

The operative member may be arranged to be rotatable by thumb and forefinger such that the tool station may be rotated using a single hand.

The operative member may be connected to the tool station whereby one rotation of the operative member in the first multiplying region is arranged to cause a predetermined number of rotations of the tool station in the second multiplying region. A combined multiplying effect of the first multiplying region and the second multiplying region may be such that one rotation of the operative member causes more than one rotation of the tool station. Alternatively, a combined multiplying effect of the first multiplying region and the second multiplying region may be such that one rotation of the operative member causes less than or equal to one rotation of the tool station.

The movement of the operative member about the second axis may be arranged to cause a drive member extending in the direction of the second axis to drive the tool station about the first axis.

The operative member may mesh with at least one planet gear to drive a sun gear on the drive member. In this way, one rotation of the operative member may be arranged to cause more than one rotation of the sun gear.

The drive member may be arranged to cooperate with the tool station via a bevel gear set. In this way one rotation of the operative member may be arranged to cause more than one rotation of a bevel pinion gear of the bevel gear set at the tool station. In this way, the operative member may be arranged to transfer drive to the tool station through the drive member in such a way that one rotation of the operative member causes more than one rotation of the tool station. Alternatively, the operative member may be arranged to transfer drive to the tool station through the drive member in such a way that one rotation of the operative member causes less than or greater than one rotation of the tool station.

The operative member may be mounted to rotate about the handle. The operative member may be mounted on the handle in manner in which it may be rotatable about the handle at a location between the handle and the tool station.

The tool station may include a ratchet mechanism whereby the tool station is only rotatable in one direction. Suitably, the ratchet mechanism may be selectively operable to commit the tool station to rotate in either one direction or an opposed second direction. Suitably, the ratchet mechanism may be selectively operable to prevent the tool station from rotating.

The hand tool may comprise a socket wrench.

According to a still further aspect of the present invention, there is provided a method of using a hand tool in a first mode of operation in which rotational movement of a handle about a first axis causes a tool station to rotate about the first axis. Also, the tool may be used in a second mode of operation in which an operative member located in a first multiplying region is rotated about a second axis to cause the tool station to rotate about the first axis in a second multiplying region, the first axis extending in a different direction to the second axis.

The method may comprise first using the tool in the first mode to impart a greater degree of torque at the tool station and subsequently using the tool in the second mode to impart a lesser degree of torque.

The second mode may be used to drive the tool station at a higher speed than the first mode.

The method may comprise using a single hand to cause movement in first and second mode with the handle being held in both modes of operation.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which: Figure 1 shows a side view of and embodiment of a hand tool of an embodiment of the present invention; Figure 2 shows a plan view of the hand tool of Figure 1; Figure 3 shows a sectional side view through the hand tool of the Figure 1; Figure 4 shows a sectional side view through a ratchet mechanism of an embodiment of the present invention; Figure 5 shows a sectional side view through a revolving handle of an embodiment of the present invention; Figure 6 shows a plan view of the hand tool of Figure 1 showing a partial section of the ratchet mechanism of Figure 4 comprising a pawl arrangement; Figure 7 shows a section through the ratchet mechanism of Figure 4 showing the pawl arrangement engaged for anti-clockwise operation of a ratchet wheel; Figure 8 shows a section through the ratchet mechanism of Figure 4 showing the pawl arrangement engaged to prevent movement of the ratchet wheel; Figure 9 shows a section through the ratchet mechanism of Figure 4 showing the pawl arrangement engaged for clockwise operation of the ratchet wheel; Figure 10 shows a schematic illustration displaying an example of the operation of the hand tool of Figure 1; and Figure 11 shows an exploded view of the components of the hand tool of Figure 1.

Figures 1-11 show a hand tool of an example embodiment of the present invention. The hand tool shown in Figure 1 and 2 is a ratchet wrench comprising a body 1, a revolving handle 2 and a conventional handle 3, but it should be understood that the present invention is not limited to such a hand tool. The revolving handle 2 is rotatable about a longitudinal axis A of the body 1 to drive an output shaft 5. The output shaft 5 transfers that drive to a ratchet wheel 10 to operate the tool-bit attached to the ratchet mechanism.

The revolving handle 2 is a rotator which is disposed in the conventional handle 3 to allow a single handed operation of the hand tool. A user of the tool is able to grip the conventional handle 3 with part of their hand and rotate the revolving handle 2 with the other parts of their hand, such as their thumb and forefinger. In this way, the hand tool of the present invention provides a convenient and compact way of rotating the ratchet wheel 10 when the torque is insufficient to trigger the ratchet mechanism.

The revolving handle 2 is located axially on the tool body 1 and the output shaft 5 is arranged to extend from within the body 1 concentrically to the revolving handle 2. First and second rotatable elements 4 are arranged to mesh with and between the revolving handle 2 and the output shaft 5 to transfer drive from the revolving handle 2 to the output shaft 5.

The revolving handle 2, the rotatable element 4 and the shaft 5 are arranged in the tool body 1 to form a planetary gear set. The revolving handle 2 forms an annulus gear of the planetary gear set. The rotatable elements 4 form a planet gear of the planetary gear set. The output shaft 5 comprises a sun gear of the planetary gear set. The annulus gear is arranged to rotate longitudinally about the same axis as a sun gear which is coupled to the output shaft 5. In this way, the drive provided to the annulus gear 2 is passed on to the sun gear and output shaft 5 using at least one planet gear 4. That is, the hand tool can have 1, 2, 3, 4 or more planet gears.

The planet gears 4 are arranged to be rotation multipliers. That is, the gear ratio of the revolving handle 2 to the planet gear 4, and the gear ratio of the planet gear 4 to the sun gear is configured such that the output shaft 5 rotates more times about its longitudinal axis than the revolving handle 2 and planet gears 4 rotate about their longitudinal axis. For example, the gear ratio between the revolving handle 2 and the sun gear is 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, and 1:5.

Figures 3, 5 and 11 show how the planetary gear set is arranged in the tool body 1. A carrier 6 featuring a first and a second protrusion 4A is arranged in the tool body 1. The planet gears 4 are arranged on the protrusions 4A and are rotatable thereabout. A sleeve 7 fits over the carrier 6 to align the planet gears 4 with an annulus gear of the revolving handle 2 and to provide correct meshing of the planet gears 4 with the revolving handle 2. In use, as the revolving handle 2 is turned, the carrier 6 reacts against the housing, causing the planet gears 4 turn about their axial mountings. This action in turn transfers drive to the sun gear coupled with the output shaft 5.

Figures 3 and 4 show that the output shaft 5 extends from the revolving handle 2 into a ratchet mechanism. The output shaft 5 has an operative end which comprises a bevel pinion gear 8.

The bevel pinion gear 8 is arranged to mesh with a bevel gear wheel 9 of the ratchet mechanism that is connected to the ratchet wheel 10. When drive is transferred to the output shaft 5, the bevel gear wheel 9 transfers that drive to the ratchet wheel 10 on an axis perpendicular to the longitudinal axis about which the shaft 5 rotates. The ratchet wheel 10 can be constructed to provide a generic tool drive member to which an assortment of tool-bits

are connectable.

The hand tool is arranged such that one rotation of the revolving handle 2 causes more than one rotation of the bevel pinion gear 8. This effect is achieved by configuring the gear ratio between the planet gear 4 and the sun gear. That is, the gear ratio between the revolving handle2and the bevel pinion8isforexample, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, and 1:5.

In this way a rotation multiplying effect is achieved between the twisting input supplied to the revolving handle 2 and the rotation output of the bevel pinion gear 8. If for example the gear ratio of the revolving handle 2 to the bevel pinion gear 8 is 1:2, then one rotation of the revolving handle will cause 2 rotations of the bevel pinion gear 8. In another example the gear ratio of the bevel pinion gear to the bevel gear may be equal to or less than 1:1 and, alternatively or additionally the gear ratios between the revolving handle 2 and the bevel pinion gear may be equal to or less than 1:1. Thus, it may be possible for the ratio of the rotation of the handle 2 to the rotation of the ratchet wheel to be equal to or less than 1:1.

In the hand tool, the bevel pinion gear 8 meshes with the bevel gear wheel 9 to rotate the ratchet wheel 10. Due to the gear ratio between the revolving handle 2 and the bevel pinion gear 8, the rotation multiplying effect results in an increased number of rotations of the ratchet wheel 10 per rotation of the revolving handle. For example, if the gear ratio between the revolving handle 2 and the bevel pinion gear is 1:4, and the gear ratio between the bevel pinion gear 8 and the ratchet wheel 10 is 1:2, then the overall ratio of the revolving handle 2 to the ratchet wheel 10 is 1:2. That is, to cause the ratchet wheel 10 to rotate once, the revolving handle 2 need only be rotated half a turn, which results in the hand tool of the present invention having a rotation multiplying effect when compared to driving mechanisms of the prior art which would require 2 rotations of a handle or driving member to achieve one rotation of a ratchet wheel.

It should be understood that this hand tool arrangement is one example of how the rotation multiplying effect could be achieved and other hand tool arrangements are possible. For example, if the gear ratio of the bevel pinion gear 8 to the ratchet wheel 10 is 1: 3, and if the gear ratio of the revolving handle to the bevel pinion gear 8 is 0.25:1, 0.5:1, 0.75:1, 1:1, 1.25:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1 and 5:1, then the overall ratio between the revolving handle 2 and the ratchet wheel 10 is 1:11/3, 1:2/3, 1./9, 1:1/3, 1/15, 1:2/9, 1:1/6, 1:2/15, 1/9, 1:2/21, 1:1/12, 12/27 1:1/15. That is, the connection of the revolving handle 2 with the bevel pinion gear 8 forms a first rotation multiplying region and the connection of the bevel pinion gear 8 with the ratchet wheel 10 forms a second rotation multiplying region. The combined effect of the multiplying regions is to multiply the number of rotations up or down that one rotation of the revolving handle 2 causes to the ratchet wheel 10.

Figures 4 and 6-9 show a switch arrangement 11 used to switch one or both of a first or a second set of engagement members 15 and 16 between a configuration in which the ratchet wheel 10 is able to rotate in a clockwise direction or an anti-clockwise direction or a configuration in which the ratchet wheel is prevented from being rotated. The switch 11 is moveable from side to side, and is connected to the tab plate 13 to give an articulating joint.

The tab plate 13 comprises a tab or protrusion that is arranged to selectively engage the first and/or the second set of engagement members with the ratchet wheel 10.

Each of the engagement members 15 and 16 comprise a pawl and a biasing means comprising a spring that biases the pawl towards a position in which the pawl is engaged with the ratchet wheel. The engagement member 15,16 comprises one or more pawl and spring.

When the engagement member 15, 16 comprises two pawls and springs, for example, the first pawl and spring is arranged on an opposite side of the ratchet wheel to the second pawl and spring.

It is of course possible to arrange the pawls and springs at any point around the ratchet wheel 10.

In use, when the switch 11 is operated the tab plate 13 moves to cause either the engagement member 15 or the engagement member 16 or all engagement members 15,16 to engage with the ratchet wheel.

Figure 4 shows a spring with a ball 12 located in notches in an end plate 14. The spring and ball 12 serve to hold the switch 11 and the tab plate 13 in position when switching.

Figures 7, 8 & 9 show how, by moving the switch 11 from side to side, alternate engagement members 15 and 16 can be engaged or disengaged from the ratchet wheel 10. Accordingly, the ratcheting action of the mechanism can be selected to be either a clockwise, as shown in Figure 9, or counter-clockwise direction, as shown in Figure 7. Also, by positioning the switch 11 in the mid position as shown in Figure 8 all the engagement members 15 and 16 are engaged on the ratchet wheel, and the wrench is locked in both clockwise and counter-clockwise directions.

In use, if for example a fastener, such as a nut or a bolt, with a right hand thread is to be removed, the wrench can be set to operate in a counter-clockwise direction, by switching the engagement members 15 to the position as shown in Figure 7. Likewise, if a right hand threaded bolt is to be tightened or a left hand threaded fastener removed the engagement members 16 are switched as shown in Figure 9.

If the engagement members 15 are arranged as shown in Figure 7, to remove a fastener the wrench is held firmly using the handle 3 and rotating the handle 3 about the fastener in a counter-clockwise direction. The engagement members 15 allow the ratcheting action to be performed. As the fastener becomes loose and there is not sufficient torque to trigger the ratcheting action, the user then operates the revolving handle 2. The revolving handle 2 is able to be turned counter-clockwise to rotate the fastener counter-clockwise to continue its removal.

The removal of the fastener is achievable because the ratchet wheel is now being driven in the same counter-clockwise direction, however because the tool body 1 is being held the engagement members 15 can be disengaged from the ratchet wheel. Figure 10 shows the relative rotations of all the parts in the driving mechanism, as the handle is turned counter-clockwise. Although not shown if the revolving handle were rotated clockwise the opposite rotations would be achieved.

In this way, the hand tool of the present invention provides a convenient implement for quickly removing fasteners owing to the multiplying effect produced by the planetary gear set. Also, the problem of fouling against neighbouring element is reduced.

Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

Claims: 1. A hand tool comprising a first mode of operation in which rotational movement of a handle about a first axis is arranged to cause a tool station to rotate about the first axis; the hand tool comprising a second mode of operation in which an operative member is able to be rotated about a second axis in a first multiplying region to cause the tool station to rotate about the first axis in a second multiplying region, the second axis extending in a different direction to the first axis.
2. A hand tool as claimed in claim 1 in which the first axis extends through the second axis.
3. A hand tool as claimed in any preceding claim in which the second axis is arranged to rotate about a radius of the first axis and is arranged to move when the handle is moved about the first axis.
4. A hand tool as claimed in any preceding claim in which the operative member is connected to the tool station whereby one rotation of the operative member in the first multiplying region is arranged to cause a predetermined number of rotations of the tool station in the second multiplying region.
5. A hand tool as claimed in claim 4 in which a combined multiplying effect of the first multiplying region and the second multiplying region is such that one rotation of the operative member causes more than one rotation of the tool station.
6. A hand tool as claimed in claim 4 in which a combined multiplying effect of the first multiplying region and the second multiplying region is such that one rotation of the operative member causes less than or equal to one rotation of the tool station.
7. A hand tool as claimed in any preceding claim in which movement of the operative member about the second axis is arranged to cause a drive member extending in the direction of the second axis to drive the tool station about the first axis.
8. A hand tool as claimed in claim 7 in which at least one planet gear meshes with the operative member to drive a sun gear on the drive member.
9. A hand tool as claimed in claim 8 in which one rotation of the operative member is arranged to cause more than one rotation of the sun gear.11. A hand tool as claimed in any of 8 to 10 in which the drive member is arranged to cooperate with the tool station via a bevel gear set.12. A hand tool as claimed in claim 11 when dependent upon claim 4 or claim 5 or any of claims 7 to 9 when dependent upon claim 4 or claim 5 in which one rotation of the operative member is arranged to cause more than one rotation of the drive member thereby causing more than one rotation of a bevel pinion gear of the bevel gear set at the tool station.13. A hand tool as claimed in any preceding claim in which the operative member is mounted on the handle and being rotatable about the handle at a location between the handle and the tool station.14. A hand tool as claimed in any preceding claim in which the tool station includes a ratchet mechanism whereby the tool station is able to be constrained to rotate in one direction.15. A hand tool as claimed in claim 14 in which the ratchet mechanism is selectively operable to constrain the tool station to rotate in either one direction or an opposed second direction.16. A hand tool as claimed in claim 14 in which the tool station is able to be prevented from rotating.17. A hand tool as claimed in any preceding claim comprising a socket wrench.18. A method of using a hand tool being used in a first mode of operation in which rotational movement of a handle about a first axis causes a tool station to rotate about the first axis, the tool also being used in a second mode of operation in which an operative member located in a first multiplying region is rotated about a second axis to cause the tool station to rotate about the first axis in a second multiplying region, the second axis extending in a different direction to the second axis.19. A method as claimed in claim 18 in which one rotation of the operative member in the first multiplying region is arranged to cause a predetermined number of rotations of the tool station in the second multiplying region.20. A method as claimed in claim 19 in which a combined multiplying effect of the first multiplying region and the second multiplying region is such that one rotation of the operative member causes more than one rotation of the tool station.21. A method as claimed in claim 19 in which a combined multiplying effect of the first multiplying region and the second multiplying region is such that one rotation of the operative member causes less than or equal to one rotation of the tool station.22. A method as claimed in claim 18 in which the operative member is located between the handle and the tool station.23. A method as claimed in any of claims 18 to 22 comprising first using the tool in the first mode to impart a greater degree of torque at the tool station and subsequently using the tool in the second mode to impart a lesser degree of torque.24. A method as claimed in any of claims 18 to 23 comprising using a single hand to cause movement in the first and second mode with the handle being held in both modes of operation.25. A method of using a hand tool as claimed in any of claims 18 to 24 when using a hand tool as claimed in any of claims ito 17.26. A hand tool substantially as herein described with reference to the drawings.27. A method of using a hand tool substantially as herein described with reference to the drawings.