Background of the Invention
This invention relates to a socket wrench and particularly to a clutch type socket wrench.
Wrenches having a torque transmitting socket which can engage with and disengage from a handled hollow head by means of a ratchet mechanism are known in the art. FIG. 1 shows a conventional wrench which has a direction changing knob 1 incorporating an adjusting pin 2 which is adapted to push or release a pawl member 3 to cause it to engage with or disengage from teeth 4 disposed in the inner periphery of the hollow head. The torque transmitting member of this device can transmit torque when it is turned clockwise or counter-clockwise by adjusting the knob 1. The handle of this device is pivoted at the periphery of the hollow head and has teeth 5 to engage a ball 6 so that the angle of the handle relative to the hollow head can be adjusted.
Summary of the Invention
An object of the invention is to provide a novel socket wrench of simple construction which can be easily manufactured.
Another object of the invention is to provide a socket wrench which has a handled hollow head receiving a torque transmitting sleeve member, the hollow head and the sleeve being provided with teeth which can engage with each other when the handle is turned upward or downward to cause the axis of the hollow head to incline the axis of the sleeve, and which can disengage from each other when the axis of the hollow head is in alignment with that of the sleeve, i.e. the handle is placed in a position parallel to a surface to which a workpiece is attached.
The invention provides a socket wrench which comprises a handled hollow head whose inner periphery has at least two pairs of spaced apart first teeth elongated axially and extending inward at two diametrically opposite positions. The inner periphery of the hollow has a first annular groove extending across each first tooth, each first tooth having a notch where the annular groove passes across which separates each tooth into two parts. Each part of each tooth gradually decreases in height from a point adjacent to the notch towards one of the open ends of the hollow head. A torque transmitting sleeve member is inserted in the hollow head and has an axial length greater than that of the hollow head. The sleeve member has two opposite open ends extending out from the hollow head, and an outer periphery provided with a plurality of second teeth elongated axially and extending radially therefrom. The outer periphery further has a second annular groove extending across the second teeth. Each second tooth has a second notch where the second annular groove passes across which separates each second tooth into two parts. Each part of each second tooth gradually decreases in height from a point adjacent to the second notch towards one of the open ends of the sleeve member. A substantially C-shaped locking ring is inserted in the second annular groove and extends partially into the first annular groove. The C-shaped locking ring is restricted from moving axially relative to the sleeve member. The first annular groove has a width greater than that of the second annular groove, thus permitting the hollow head to move axially to a limited amount relative to the sleeve member.
The present exemplary preferred embodiment will be described in detail with reference to the accompanying drawings, in which:
Brief Description of the Drawings
FIG. 1 shows a wrench in the prior art;
FIG. 2 is an exploded view of a clutch type wrench according to the present invention;
FIG. 3 is a perspective of the wrench of FIG. 2;
FIG. 4 is a sectional view of the wrench of FIG. 1 in an inoperative position;
FIGS. 5 and 6 are sectional views of the wrench of FIG. 1 in an operative position; and
FIGS. 7A, 7B and 7C show different sockets or sleeve member of the wrench of FIG. 2 with different inner cross sections.
Detailed Description of the Preferred Embodiment
Referring to the drawings, a clutch type wrench is shown having a handle 10 which has a cylindrical hollow head 11 formed integrally therewith. The hollow head 11 has an inner periphery 12 on which are formed two pairs of teeth 13 elongated in an axial direction and extending inward. Each pair of teeth 13 are disposed at a diametrically opposite position with the other. An annular groove 14 extends along the circumferential length of the inner periphery 12, passing across the teeth 13. Each tooth 13 is notched where the annular groove 13 passes across in such a manner that the tooth 13 has two opposing parallel faces 151 to confine a notch 15 which divides the tooth 13 into two parts. The two parts of each tooth 13 gradually decreases in height from the notch 15 respectively towards the two open ends of the hollow head so that a slanted face 16 is formed on each part of each tooth 13.
A torque transmitting socket or sleeve member 20 is inserted in the hollow head 11. The axial dimension of the sleeve member 20 is greater than that of the hollow head 11 so that two opposing ends 25 and 26 of the sleeve member 20 extends out of the hollow head 11. The sleeve member 20 has an outer periphery 21 provided with a plurality of teeth 22 elongated axially and extending radially. The outer periphery 12 further has an annular groove 23 extending around the outer periphery and passing across the teeth 22. Each tooth 22 is notched where the annular groove 23 passes and is thus separated into two parts. Each part of the tooth 22 decreases gradually in height from the point near the annular groove 23 toward one of the open ends of the sleeve member 20 so that a slanted face 24 is formed on each part of each tooth 22.
A substantially C-shaped locking ring 30 is inserted in the annular groove 23 of the sleeve member 20 and extends partially into the annular groove 14 of the hollow head. The thickness of the C-shaped locking ring 30 is substantially similar to the width of the annular groove 23 so that the ring 30 is fitted snugly in the groove 23 and the sleeve member 20 is restricted from moving axially relative to the hollow member 11.
In assembly, the C-shaped ring 30 is inserted in the annular groove 23 of the sleeve member 20 and then the sleeve member 20 is inserted into the hollow head 11. The annular groove 14 has a width greater than that of the annular groove 23 and therefore permits the hollow member 11 to move axially a limited amount relative to the ring 30 and the sleeve member 20. Since the teeth 13 are provided with parallel faces 151 at their notches 15, the C-shaped rings will never be released from the annular groove.
In operation, the sleeve member 20 is sleeved around a workpiece 50 and the handle 10 is turned by the operator. When the handle 10 is placed in a position parallel to a plane perpendicular to the axis of the sleeve member 20 as shown in FIG. 4, the teeth 13 and 22 do not engage with each other so that, although the handle 10 is turned clockwise or counterclockwise, the torque transmitting sleeve member 20 is inoperative. When the handle 10 is turned upward as shown in FIG. 5, the axis of the hollow head 11 inclines to the axis of the sleeve member 20. In this situation, the teeth 13 are moved and both upper and lower parts of the teeth 13 engage respectively with the upper and lower parts of the teeth 22 of the sleeve member 20. When the handle 10 is turned downward, the teeth 13 and 22 can also engage with each other as shown in FIG. 6.
It can be noted that one can easily lever the handle of the wrench of the invention by turning the handle upward or downward to move it forward and then placing the handle in a position parallel to the surface to which the workpiece is attached, so as to move the handle backward. The upward or downward inclining angle .beta. of the handle relative to the plane to which the workpiece is attached depends on the angle .alpha. of the slanted face 24 of the teeth 22 plus the angle .theta. of the slanted face 16 of the teeth 13.
In addition to the sleeve member 20 which has an inner cross-section as shown in FIG. 2, the sleeve member of the present invention may have an inner cross-section as shown in any one of FIGS. 7A, 7B and 7C.
With the invention thus explained, it is apparent that numerous modifications and variation can be made without departing from the scope of the invention. It is therefore intended that the invention be limited as only indicated in the appended claims.