Reversible ratchet wrench

A reversible ratchet wrench includes a main body, a drive gear housed within a gear end of the main body, and a pawl assembly housed within a pawl end of the main body. Further included are a reversing lever, a screw for securing the reversing lever to the pawl assembly, and a coverplate for retaining the drive gear and pawl assembly within their respective gear and pawl ends in the main body. The coverplate is coupled to the screw in a way which permits rotation of the reversing lever relative to the coverplate.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to reversible ratchet wrenches and, in 
particular to the disposition and retention of a reversing lever, a pawl, 
a gear, and a cover plate using a single screw. 
2. Description of the Prior Art 
The reversible ratchet wrench has been known for many years and there are 
numerous ratchet tools with varying handles, driver assemblies, pawl 
assemblies, and reversing levers. 
Recently, there has been a demand for a ratchet wrench which has 
comparatively few separate parts, thus significantly reducing the need for 
expensive and extensive tooling and parts inventory, which ratchet wrench 
can also be assembled easily and rapidly by relatively unskilled labor, 
and for which wrench, repairs and replacement of parts can be easily 
accomplished. 
One such wrench is disclosed in U.S. Pat. No. 5,178,047 to Arnold et al. 
This wrench reduces the number of separate parts common in prior tools, by 
eliminating the need for washers and retaining rings, as well as the 
number of screws needed to join conventional parts, such as the gear 
assembly, the pawl assembly, and the reversing lever. This is made 
possible by the cooperative engagement of the pawl and gear assemblies 
with a uniquely configured reversing lever having a complex geometry. Due 
to the nature and construction of the cooperating parts, additional parts 
are obviated. In particular, the Arnold wrench comprises a reversing lever 
having a top portion, a tab extending outwardly therefrom and a stem 
depending downwardly from the top portion. The stem is received in a 
vertical bore in the pawl to permit rotation of the pawl between a first 
or forward condition and a second or reverse condition. The teeth on the 
pawl selectively engage the teeth on a gear to permit rotation of the 
gear, as well as of a socket or other driver connected thereto. The wrench 
further includes a body having first and second part-circular cavities 
formed therein and communicating with each other. Through the first and 
second cavities are received the gear and lever/pawl assemblies, 
respectively. The unique geometry of the reverse lever relative to the 
pawl and the gear in combination with a cover plate cooperate to hold the 
assemblies in their respective cavities, once assembly is completed. The 
use of the cover plate is important to reduce the entry of dirt into the 
cavities, as well as to reduce wear and damage to the gear and pawl 
assemblies, to retain the gear and pawl and to provide a bearing surface 
therefore. 
While the Arnold wrench is an improvement over tools requiring a greater 
number of cooperating parts, the complex geometry of the reversing lever, 
the gear and pawl assemblies, and the coverplate makes tooling of 
individual parts an arduous and expensive process. 
SUMMARY OF THE INVENTION 
It is a general object of the invention to provide a reversible ratchet 
wrench which is economical and easy to manufacture. 
It is another object of the invention to provide a reversible ratchet 
wrench the individual parts of which are of a simple geometry, being easy 
and inexpensive to produce, and minimizing the need for tools in 
disassembly and replacement of such parts. 
These and other features of the invention are attained by providing a 
reversible ratchet wrench including a main body, a drive gear housed 
within a gear end of the main body, and a pawl assembly housed within a 
pawl end of the main body. Further included are a reversing lever, a screw 
for securing the reversing lever to the pawl assembly, and a coverplate 
for retaining the drive gear and pawl assembly within their respective 
gear and pawl ends in the main body. The coverplate is coupled to the 
screw in a way which permits rotation of the reversing lever relative to 
the coverplate. 
The invention consists of certain novel features and a combination of parts 
hereinafter fully described, illustrated in the accompanying drawings, and 
particularly pointed out in the appended claims, it being understood that 
various changes in the details may be made without departing from the 
spirit, or sacrificing any of the advantages of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1-3, there is illustrated a reversible ratchet wrench 
generally designated by the numeral 10 and including a main body 20, a 
drive gear 40, a pawl assembly 60, a reversing lever 80, a self-tapping 
screw 100 and a coverplate 110, constructed in accordance with and 
embodying the features of the present invention. 
Main body 20 consists of a handle portion 21 and a head portion 22. The 
head portion 22 includes a pawl end 23 and a drive gear end 24 and is 
further characterized by a top surface 25 and a bottom surface 26. 
Referring to FIG. 3, head portion 22 has two part-circularly cylindrical 
cavities formed therein. A first cavity 27, distal to the handle portion 
21, and a second cavity 28, proximal to the handle portion 21. The 
cavities 27 and 28 are formed in the bottom surface 26 of the head portion 
22 and extend therein toward the top surface 25. The cavities 27 and 28 
intersect and communicate with each other and have parallel central axes. 
The second cavity 28 has a diameter smaller than the diameter of the first 
cavity 27. The first cavity 27 is closed at the inner end thereof by a 
wall 29, and is spaced a predetermined distance below the top surface 25 
of head portion 22. The second cavity 28 is partially closed at a top end 
thereof by the same wall 29, but communicates with a coaxial circular 
opening 30 in the wall 29, of smaller diameter than the diameter of cavity 
28. Since opening 30 is smaller than cavity 28, wall 29 forms a shoulder 
31 on the top region of cavity 28. 
A blind-ended bore 32 is formed in the head portion 22, communicating with 
the rear end of the cavity 28, a slight distance above the bottom surface 
26 and inclined upwardly toward the top surface 25. A slot 33 is formed in 
the inner surface of a distal end portion of a peripheral side wall 34 of 
drive gear end 24, a fixed distance up from the bottom surface 26, as 
shown in FIG. 2. 
The drive gear 40 is disposed within the drive gear end 24 of head portion 
22, which drive gear end 24 is defined by the first cavity 27, slot 33 and 
corresponding surrounding wall 29. Drive gear 40 has a substantially 
cylindrical gear portion 41 with a diameter slightly smaller than the 
diameter of first cavity 27. A plurality of teeth 42 are uniformly spaced 
apart about the circumference of the gear portion 41. The teeth 42 are 
parallel to the axis of the first cavity 27. The flat top and bottom 
surfaces 45 and 46 of gear portion 41 are beveled or chamfered, as at 43 
and 44, around the circumference thereof. Flat surface 45 abuts the inner 
surface of wall 29. From flat surface 46 extends a drive portion 47 
consisting of a cylindrical wall 48, frustoconical wall 49, and a drive 
lug 50, which lug is substantially square in transverse cross section, but 
may have other shapes, and is formed and dimensioned to be received in a 
conventional socket wrench (not shown). Also, the body of lug 50, may 
include a detent ball 51 to retain a conventional socket wrench thereon in 
a manner known to persons skilled in the art. 
The pawl assembly 60 is disposed within the pawl end 23 of head portion 22, 
which pawl end 23 is defined by the second cavity 28, the corresponding 
surrounding wall 29, opening 30, corresponding surrounding end wall 34 and 
by blind-ended bore 32. Referring also to FIG. 5, the pawl assembly 60 
includes a partially cylindrical pawl 61, a ball 62, and a spring 63. A 
forward portion of the pawl 61 has two sets of spaced apart teeth 64 
formed thereon. The teeth 64 on the pawl 61 extend the entire height of 
the pawl parallel to the axis of the second cavity 28 when the pawl 61 is 
disposed therein. When so disposed, the teeth 64 of one set of pawl 61 
engage the teeth 42 on the gear portion 41. In this manner, when the pawl 
61 is in a first condition with the teeth 64 of the one set engaging the 
teeth 42 on the gear portion 41, as shown in FIG. 4, the gear portion may 
rotate in a first direction but is prevented from rotating in a second 
(opposite) direction. Similarly, when the pawl is in a second condition 
with teeth 64 of the other set engaging the teeth 42 on the gear portion 
41, the gear portion 41 may rotate in the second direction but is 
prevented from rotating in the first (now opposite) direction. 
The pawl 61 has a center bore 65 therethrough from a top 66 of the pawl 61 
to a bottom 67 of the pawl 61. A top portion 68 of center bore 65 
extending from top 66 to a fixed distance from bottom 67 is substantially 
semicircular while a remaining bottom portion 69 is substantially circular 
and extends through to the bottom 67 of pawl 61. The pawl 61 further has a 
pair of spaced-apart pockets 70, 71 formed on the rear end thereof. The 
pockets are shown extending the entire height of the pawl 61. The ball 62 
and the spring 63 resiliently cooperate to position the ball accordingly 
in one of the pockets 70, 71. When reversing lever 80 is in a position for 
rotation of the pawl 61 in the first direction, ball 62 will rest on 
convex wall surface 72 as shown in FIG. 4. Similarly, when the reversing 
lever 80 is in a position for rotation in the reverse or second direction, 
the ball 62 will rest on convex wall surface 73. Thus, the ball 62 and 
spring 63 cooperate with the pockets 70 and 71 to resiliently hold the 
pawl 61 in either of its two engaged positions in a well-known manner. 
A reversing lever 80 is connected to the pawl 61 to effect rotation of the 
pawl between the first and second conditions. The lever 80 has a 
substantially cylindrical portion 81 on which a tab 82 is formed extending 
outwardly therefrom, as shown in FIG. 5. The tab 82 may be textured and/or 
grooved to reduce slippage when the tab is grasped by a person using the 
wrench. The lever 80 includes a stem portion 83 extending vertically from 
the cylindrical portion 81. Stem portion 83 has a cylindrical shoulder 84, 
depending downwardly from the cylindrical portion 81, and is dimensioned 
to be received by the opening 30 in head portion 22. The cylindrical 
shoulder 84 extends into the second circular cavity 28 and is coaxial 
therewith. The top portion 81 of reversing lever 80 is of greater diameter 
than that of cylindrical shoulder 84 providing contact surfaces 85 which 
cooperate with shoulder 31 of wall 29 to prevent the lever 80 from 
slipping through the opening 30 and second cavity 28. Depending downwardly 
from a bottom surface 86 of shoulder 84, is a substantially semi-circular 
base leg 87 which is dimensioned to be received within the top portion 68 
of center bore 65 of pawl 60 and is similarly coaxial therewith. The 
polygonal shape of base leg 87 and mating engagement thereof with pawl 61 
causes pawl 61 to rotate together with the reversing lever 80 when tab 82 
is rotated in a first direction or in the second direction. The bottom 
surface 86 of shoulder 84 is coplanar with the top 66 of pawl 61. A 
cylindrical cavity 88 extends from a bottom 89 of base leg 87 and extends 
axially into the cylindrical portion 81 thereof. The cavity 88 is coaxial 
with the axis of second cavity 28 when the lever 80 is disposed in the 
pawl 61 which, in turn, is disposed in second cavity 28. 
The self-tapping screw 100, shown in FIG. 5, includes a head 101, a 
shoulder 102 extending from a flat surface 103 of head 101, and a threaded 
circular stem 104. Stem 104 is dimensioned to fit through the bottom 
portion 69 of bore 65 of pawl 61 and into threaded engagement in 
cylindrical cavity 88 of base leg 87, thereby coupling pawl 61 and reverse 
lever 80. 
To restrain the pawl assembly 60 and drive gear 40 within the respective 
drive gear end 24 and pawl end 23, a coverplate 110 is used. Referring to 
FIGS. 5 and 6, coverplate 110 is generally a flat member of fixed 
thickness having two adjoining circular portions in the shape of a numeral 
eight, the thickness of coverplate 110 being slightly less than the 
thickness of shoulder 102 of screw 100. One portion 111 is smaller and the 
other portion 112 is larger. When disposed on the main body 20, the 
coverplate 110 includes a tab portion 113 dimensioned to be received in 
slot 33, to permit the coverplate 110 to fit through the opening in bottom 
surface 26 of the head portion 22 defined by the cavities 27 and 28. The 
surface of larger portion 112 is coplanar with the flat bottom surface 46 
of drive gear 40 and further includes a circular opening 114 having a 
diameter slightly larger than the diameter of cylindrical wall 48 such 
that drive portion 47 of drive gear 40 readily extends therethrough. The 
surface of smaller portion 111 is coplanar with the bottom 67 of pawl 61 
and further includes a circular screw-fitting opening 115 having a 
diameter larger than the diameter of shoulder 102 of screw 100, but 
smaller than the diameter of head 101. Thus, during installation and 
assembly, the threaded circular stem 104 extends axially through 
screw-fitting opening 115, threadedly engaging lever cylindrical cavity 88 
and coupling coverplate 110 to pawl end 23 of head portion 22. 
Because the thickness of the coverplate 110 is smaller than the height of 
shoulder 102 of screw 100, and because the diameter of screw-fitting 
opening 115 of coverplate 110 is smaller than the diameter of head 101 of 
screw 100, the screw 100 is permitted to rotate freely relative to the 
coverplate 110. Thus, the coverplate 110 is secured in position by way of 
the engagement of slot 33 with tab portion 113 at one end (the gear end 
24) and by way of the screw 100 locating smaller portion 111 adjacent to 
the pawl 61. 
Thus, a single self-tapping screw operates to fasten the reversing lever 80 
to the pawl assembly 60, while simultaneously securing one end of the 
coverplate 110 to the wrench body 20. 
In the preferred embodiment, the screw 100 has been described as a 
self-tapping screw, i.e., a thread forming screw or a thread cutting 
screw, which is turned into a smooth, untapped bore of a reversing lever 
80. Preferably, therefore, the reversing lever should be of a metallic 
material softer than the material of the screw, such as a soft zinc die 
casting. The use of a self-tapping screw ensures that the lever 80 and 
screw 100 are fixedly secured and unlikely to be unthreaded as a result of 
lever overuse or wrench abuse. 
It is envisioned that a wide variety of functionally equivalent coverplate 
constructions can be easily substituted for the tab-type construction 
described in the preferred embodiment. However, the disclosed tab 
coverplate construction most economically achieves the goal of 
facilitating installation and minimizing tooling and is therefore 
preferable to other like constructions. 
The single screw construction of the reversible ratchet wrench of the 
present invention will inevitably result in economical production with the 
ultimate effect of low retail cost per unit. 
Additionally, because the individual parts have a relatively simple 
geometry, assembly, repair and/or replacement thereof can be easily 
accomplished. 
While particular embodiments of the present invention have been shown and 
described, it will be obvious to those skilled in the art that changes and 
modifications may be made without departing from the invention in its 
broader aspects. Therefore, the aim in the appended claims is to cover all 
such changes and modifications as fall within the true spirit and scope of 
the invention. The matter set forth in the foregoing description and 
accompanying drawings is offered by way of illustration only and not as a 
limitation. The actual scope of the invention is intended to be defined in 
the following claims when viewed in their proper perspective based on the 
prior art.