IE74212B1 - A driver for a rotable tool - Google Patents

Description

A Driver for a Rotatable Tool This invention relates to a driver for a rotatable tool, and in particular a driver for a spanner for use where access to fasteners such as nuts and bolts is restricted.

In this specification the term rotatable tool means tools which are rotated for operation, including tools such as spanners, screwdrivers and the like, and also tools having a tool head at least portion of which is rotated for operation.

The prior art shows a number of spanners for use in confined spaces generally comprising an elongate body, a rotatable tool mounted on the body and drive means on the body to rotate the tool on the body with the body held stationary. Some examples of these are shown in Patent Specification Nos GB 2,014,495, US 4,339,969 and FR 2,276,146. However, a drawback of these devices is they are of relatively complicated construction with, in some cases, a large number of moving parts, and further an accurately measured torque cannot be applied to the tool.

The present invention is directed towards overcoming this problem.

According to the invention there is provided a driver for a hand tool of the type having an elongate handle and a rotatable tool carrier for a tool head mounted adjacent one end of the handle and a rotatable drive input also provided on the handle at a point remote from the tool carrier, the driver having drive means for the tool carrier operable remote from the tool carrier with the handle substantially stationary and in which the drive 7421 2 - 2 means comprises the rotatable drive input and an elongate link arm pivotally connected to a pair of spaced-apart crank arms which in turn are connected to the drive input and the tool carrier respectively, the pair of spaced-apart crank arms being parallel to each other and the elongate link arm being parallel with the elongate handle on which the drive input and tool carrier are mounted, so that the drive means forms a substantially parallelogram linkage whereby an accurately measured torque can be applied to the tool.

In another embodiment, the crank arms are releasably connected to the drive input and the tool carrier.

Id a further embodiment, the crank arms are pivotal within a predetermined arc.

Ideally the drive means is reversible to allow rotation of the tool carrier in opposite directions.

Preferably also a ratchet mechanism is incorporated in the drive means. Ideally the ratchet mechanism is mounted between the drive output means and the tool support.

In a particularly preferred embodiment the drive means has a drive input crank arm pivotally mounted on the handle, a link member pivotally attached to the crank arm and connected to the tool carrier to pivot the tool carrier in response to pivoting of the crank arm.

In some cases the tool carrier may incorporate a ratchet mechanism. The ratchet mechanism may comprise a ratchet wheel on the tool carrier and an associated pawl and the drive means is engagable with the ratchet wheel for rotation of the tool carrier.

In a further embodiment the drive means comprises a pair of spaced-apart crank arms pivotally mounted on the handle with a link member extending therebetween, one of the crank arms being mounted adjacent the tool carrier and the other of the crank arms being mounted remote from the tool carrier, the crank arm adjacent the tool carrier having an outwardly extending push rod for engagement with the ratchet wheel of the ratchet mechanism incorporated in the tool carrier.

Ideally the tool carrier has a drive head, such as a square drive head for example, with which any one of a number of tools can be detachably engaged.

In another aspect the invention provides a tool having an elongate handle, a rotatable tool head mounted on the handle, and drive means on the handle to rotate the tool head on the handle with the handle held stationary, the drive means incorporating a rotatable drive input.

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:20 Fig. 1 is an elevational view of a spanner incorporating a driver according to the invention; Fig. 2 is a perspective view of another spanner; Fig. 3 is a perspective exploded view of the spanner of Fig· 2; Fig. 4 is a perspective view of another spanner according to the invention; Fig. 5 is an exploded perspective view of the spanner of Fig. 4; Fig. 6 is a detailed perspective view of a head portion of a circlip plier tool incorporating a driver according to the invention, Fig. 7 is a partially cut-away detailed perspective view of a drive input portion of the tool of Fig. 6, Fig. 8 is a perspective view of a spanner incorporating a driver according to the invention, Fig. 9 is a front elevational view of the spanner of Fig. 8, Fig. 10 is a rear elevational view of the spanner of Fig. 8 , Figs. 11 and 12 are side elevational views showing each side of the spanner of Fig. 8, Fig. 13 is a detailed perspective view of a head portion of another spanner incorporating a driver according to the invention, - 5 Fig. 14 is a detailed perspective view of an alternative type of handgrip for use with the tools incorporating the driver of the invention, Fig. 15 is a perspective exploded view of another driver which is releasably mountable on a spanner, Fig. 16 is a detailed partially sectioned view of portion of a driver and a head portion of a spanner similar to that shown in Fig. 15 showing an alternative driver arrangement, and Fig. 17 is an elevational view of another spanner similar to the spanner shown in Fig. 1.

Referring to the drawings and initially to Fig. 1 there is illustrated a spanner according to the invention indicated generally by the reference numeral 40. The spanner 40 has an elongate body member 2 forming a handle and a handgrip 7 formed at the other end of the body member 2. A tool carrier 41 carries a square drive spigot 42 for demountably attaching socket wrenches on the spanner 40 in use. A driver comprising a movable parallel linkage mechanism indicated generally by the reference numeral 10 is mounted on the body member 2 and connected to the tool carrier to rotate the drive spigot 42. In this case the linkage mechanism comprises a crank arm 12 pivotally mounted on the body member 2 remote from the spanner head 3 and extending laterally of the body member 2. A link arm 13 pivotally connected to the crank arm 12 extends from the crank arm 12 and is pivotally connected at 14 to another crank arm which is connected at the other end thereof to the drive spigot 42. Also the crank arm 12 is mounted on the body member 2 by a pivot pin 35 having a central slot 36 shaped to receive a - 6 standard square drive tool for socket wrenches. The outer ends of the pivot pin 35 are a hexagonal shape for engagement by a spanner to turn the crank arm 12.

In use, a conventional spanner (not shown) is engaged with an outer end of the pivot pin 35 on the crank arm 12. Rotation of the pivot pin 35 causes the crank arm 12 to turn which in turn causes the link arm 13 to rotate the tool carrier and drive spigot 42 on the body member 2 thus tightening or releasing the fastener. it will be appreciated that the invention provides a spanner 40 which is operable without having to swing it through a wide arc to release or tighten fasteners such as nuts and bolts. It can therefore be advantageously used to release or fasten nuts and bolts which are mounted in relatively inaccessible locations on machinery for example.

Referring now to Figs. 2 and 3, there is illustrated a spanner according to another embodiment, indicated generally by the reference numeral 80. The spanner 80 has a handle formed by an elongate body 81 with a handgrip 82 - Ί at one end and a rotatable tool carrier 83 mounted at the opposite end of the body 81 to the handgrip 82. Drive means 85 is provided on the body 81 to rotate the tool carrier 83 on the body 81 with the body 81 held stationary. The drive means 85 has a drive input crank arm 86 pivotally mounted on the body 81 adjacent the handgrip 82. A link arm 87 is pivotally attached at one end by a pivot pin 88 to the crank arm 86. The other end of the link member 87 is pivotally attached by a pivot pin 89 to a laterally extending crank arm 90 on the tool carrier 83. The crank arm 86 has a square drive socket 92 for engagement by an associated bar 93 with a square drive head 94 for operation of the crank arm 86. A square drive bar 95 is engagable with a complementary socket 96 on the tool carrier 83 for mounting tools such as spanners, screwdrivers and the like on the spanner 80.

In use, a socket drive tool (not shown) is mounted on the drive bar 95 and engaged with a fastener. The bar 93 can then be operated to pivot the crank arm 86 to rotate the tool carrier 83 and hence the tool mounted thereon to tighten or loosen the fastener as desired.

Fig. 3 shows the driver 80 in an exploded view illustrating the relatively simple and robust construction of the spanner 80 and the mounting of the crank arm 86 and tool carrier 83 on the body 81.

It will be appreciated that in some cases the tool support 83 may incorporate a ratchet mechanism. Alternatively, a ratchet adapter may be mounted on the bar 95.

Referring now to Fig. 4 there is illustrated another spanner 100 which is generally similar to the spanner shown in Figs. 2 and 3 · In this case, however, the spanner 100 has an adjustable handle and drive means. The - 8 spanner 100 has a handle comprising a handgrip portion 101 with a square drive 102 at its front end for mounting a bar 103 having a socket 104 at its inner end for engagement with the square drive 102 and a square drive 105 at its outer end for mounting a head portion 106 carrying a rotatable tool carrier 107. The bar 103, handgrip 101 and head portion 106 when assembled together form a handle. Drive means comprises a drive input crank arm 110 rotatably mounted on the handgrip portion 101 having a connector 111 for connection to a link bar 112 (forming the link arm) of similar size and construction to the bar 103. A connector 113 which detachably mounts at an outer end of the link bar 112 is pivotally mounted on a crank arm 114 connected to the tool carrier 107. Advantageously the bars 103, 112 can be selected to provide a spanner 100 of any desired length. The bars 103, 112 can be rigidly secured at each socket connection by means of a pin 120 extending through corresponding holes 121, 122 provided at each socket connection (only one being shown for clarity). Each pin 120 is retained in place by a spring loaded ring 124.

Referring now to Figs. 6 and 7 there is illustrated portion of tool 120 which incorporates a circlip tool 121 on the handle operable by the drive means. The tool 120 has an elongate handle 122 similar to the handle on the spanner of Figs. 2 and 3. The drive means has a drive input crank arm 123 rotatably mounted on the handle 122. A ratchet mechanism is incorporated in the arm mounting arrangement on the handle 122. The ratchet mechanism comprises teeth 124 on the arm 123 and an associated pawl 125 pivotally mounted on the handle 122 for movement between engaged positions and a central neutral position. The drive input arm 123 is connected to an associated crank arm 126 at an outer end of the handle 122 by a link member (not shown) as previously described. Also mounted - 9 at an outer end of the handle 122 are a pair of circlip engaging arms 129, 130. The arm 129 can be rigidly fixed on the outer end of the handle 122 by a pin 131 which engages within a number of spaced-apart holes 132 on the outer end of the handle 122 to fix the arm 129 at a desired angle on the outer end of the handle 122. The arm 130 is rotatable on the outer end of the handle 122 and drivably connected to the crank arm 126 through a central drive connector 127 such that movement of the crank arm 126 rotates the arm 130 for movement towards or away from the arm 129. A ratchet 135 is provided on the crank arm 126.

In use, the driver 120 can be used to engage a circlip in a confined space and expand or contract the circlip as necessary for insertion or removal on an associated machine part.

Referring now to Figs. 8 to 12 , there is illustrated a spanner 130 incorporating a driver 132 according to the invention. The spanner 130 has an elongate handle 133 which a cranked handgrip 134 at one end of the handle 133. A rotatable tool carrier 135, in this case comprising a ratchet type socket drive for tool heads such as socket spanners 136, mounted adjacent the other end of the handle 133. The driver 132 has drive means comprising an elongate link arm 138 pivotally connected to a pair of spaced-apart crank arms 139, 140. The crank arm 139 is in turn connected to the tool carrier 135. The crank arm 140 is connected to a rotatable drive input 141 rotatably mounted on the handle 133 remote from the tool carrier 135 in similar fashion to the pervious embodiments. A square drive socket 142 on the drive input 141 is engageable by a conventional drive handle 143. It will be noted that the drive means 132 forms a substantially parallel linkage. The crank arms 139, 140 are pivotal within a predetermined arc, the link arm 138 moving back and forth alongside the handle 133 to rotate the tool carrier 135 which can be rotated in either direction by means of the ratchet mechanism. It will be noted that the distance between the pivot axes at each end of the link arm 138 is equal to the distance between the pivot axis of the drive input 141 and the tool carrier 135, and the link arm 138 stays parallel to a line drawn between the pivot axes of the drive input 141 and tool carrier 135 throughout its movement.

Referring now to Fig. 13 , there is illustrated a head portion of another spanner incorporating a driver similar to that shown in the embodiment of Figs. 8 to 12 and like parts are assigned the same reference numerals. In this case, a tool carrier 145 is simply rotatable on the handle 133, no ratchet mechanism being provided. If necessary, a ratchet converter could be mounted on the tool carrier 145.

It will be noted that.a torque multiplier of conventional type, can be mounted on the drive inpur of the spanners if desired, for increasing the torque output at the tool carrier.

Referring now to Fig. 14 there is shown an alternative handgrip arrangement for the handle of any of the tools previously described. In this case, the handle 150 is formed by an enlarged loop 151 to facilitate grip.

It will be appreciated that the tools according to the invention are advantageously of relatively simple construction and can be made light and compact. They are also extremely versatile. They can incorporate a forward/reverse drive ratchet head to which any conventional tool attachment can be fitted.

Advantageously also the tool can be used to apply full torque to a fastener in any position.

Referring now to Fig. 15 there is illustrated a spanner 160 according to another embodiment having a detachable driver 161. The driver 161 has an elongate link arm 162 pivotally connected to a pair of spaced-apart crank arms 163, 164. The crank arm 164 has a turning handle 165 attached thereto. The spanner has a handle 166 with a rotatable tool carrier 167 at one end and a handgrip 168 at the other end. A rotatable drive input 169 is mounted on a handle 166 remote from the tool carrier 167 and has a socket 170 for reception of a socket drive 171 on the crank 164. A socket 172 on the crank 163 is engageable with a complementary socket drive 173 connected to the tool carrier 167. For use, the driver 161 can be snapped into engagement with the drive input 169 and the tool carrier 167 and operated as previously described by rotation of the handle 165. When not using the spanner 160 for access to confined spaces, the driver 161 can conveniently be removed allowing the handle 166 to be used as a conventional socket drive spanner.

Fig. 16 shows an alternative head for the handle 166 with a tool carrier 175 for a socket type tool head. In this case the tool carrier 175 has an elongate square socket 176 one side of which is engageable by a socket drive 178 on the crank 163, the other side of the socket 176 being engaged by a conventional square type socket drive bar 177.

Referring now to Fig. 17, there is illustrated another spanner 180 similar to the one shown in Fig. l and like parts are assigned the same reference numerals. In this case, an outer end of the body 2 is cranked at 181 having a tool carrier 182 rotatably mounted thereon for carrying -12 a socket spanner or the like. In this case, the driver comprises a link arm 183 having crank arms 184, 185 pivotally mounted at each end. The crank arms 184, 185 are pivotally mounted on the body 2 at 186, 187 respectively. The crank arm 185 is triangular and has pivotally attached thereto a short link arm 188 which in turn is pivotally attached to a crank arm 189 connected to the tool carrier 182. The spanner 180 is used in similar fashion to the spanners previously described in this case, the drive being transmitted around the cranked end of the body 2. The cranked body 2 allows access around corners.

The spanners and drivers may be of any suitable materials of construction.

The invention is not limited to the embodiments 15 hereinbefore described which may be varied in both construction and detail.

Claims (16)

CLAIMS :

1. A driver for a hand tool of the type having an elongate handle and a rotatable tool carrier for a tool head mounted adjacent one end of the handle and a 5 rotatable drive input also provided on the handle at a point remote from the tool carrier, the driver having drive means for the tool carrier operable remote from the tool carrier with the handle substantially stationary and in which the drive means comprises the rotatable drive 10 input and an elongate link arm pivotally connected to a pair of spaced-apart crank arms which in turn are connected to the drive input and the tool carrier respectively, the pair of spaced-apart crank arms being parallel to each other and the elongate link arm being 15 parallel with the elongate handle on which the drive input and tool carrier are mounted, so that the drive means forms a substantially parallelogram linkage whereby an accurately measured torque can be applied to the tool.

2. A driver as claimed in claim 1, wherein the crank 20 arms are releasably connected to the drive input and the tool carrier.

3. A driver as claimed in claim 2, wherein the crank arms are pivotal within a predetermined arc.

4. A driver as claimed in any preceding claim wherein 25 the drive means is reversible.

5. A driver as claimed in any preceding claim wherein a ratchet mechanism is incorporated in the drive; means. - 14

6. . A driver as claimed in claim 5 wherein the ratchet mechanism is mounted between the drive output means and the tool carrier.

7. . A driver as claimed in claim 5 wherein the ratchet mechanism comprises a ratchet wheel on the tool carrier and an associated pawl and the drive means is engagable with the ratchet wheel for rotation of the tool carrier.

8. . A driver as claimed in claim 5 wherein the drive means comprises a pair of spaced-apart crank arms pivotally mounted on the handle with a link arm extending therebetween, one of the crank arms being mounted adjacent the tool carrier and the other of the crank arms being mounted remote from the tool carrier, the crank arm adjacent the tool carrier having an outwardly extending push rod for engagement with the ratchet wheel of the ratchet mechanism incorporated in the tool carrier.

9. . A driver as claimed in any preceding claim wherein the drive means has a drive input crank arm pivotally mounted on the body, a link member pivotally attached to the crank arm and connected to the tool carrier to rotate the tool carrier in response to pivoting of the crank arm.

10. A driver as claimed in any preceding claim wherein the tool carrier has a drive head with which any one of a number of associated tools can be detachably engaged.

11. A driver as claimed in claim 8 wherein the drive head is of polygonal such as square cross section. 15

12. A tool incorporating a driver as claimed in any preceding claim.

13. A tool as claimed in claim 12 having a handle with a cranked handgrip. 5

14. . A tool as claimed in claim 12 or 13 having a handle with a looped handgrip.

15. . A driver substantially as hereinbefore described with reference to the accompanying drawings.

16. . A tool substantially as hereinbefore described with reference to the accompanying drawings.