Ratcheting mechanism

A ratcheting mechanism and a process for making same, including a tool handle and a gear and pivotal pawls which are urged into gear engagement by means of springs which can be assembled with the handle before a final cap or actuator is assembled over the end of the handle to enclose the pawls and the springs.

This invention relates to a ratcheting mechanism. It is particularly 
adaptable for use in a hand tool, such as a ratcheting screwdriver, and it 
is therefore disclosed in that context. 
BACKGROUND OF THIS INVENTION 
The prior art is aware of a variety of embodiments of ratcheting 
mechanisms, particularly including ratcheting screwdrivers. In the present 
invention, the mechanism includes a centrally located cylindrical gear and 
two pivotal pawls which can be placed into and out of engagement relative 
to the gear, for the desired ratcheting action. Further, the pivotal pawls 
are urged into tooth engagement with the gear by means of a spring 
operative on each pawl. An actuator is then employed for moving the pawls 
against the force of the spring and out of engagement with the gear. 
Examples of such prior art are seen in U.S. Pat. Nos. 2,744,432 and 
3,356,117 and 5,613,385 and 5,619,891. In those examples, the springs 
therein have generally a planar extending end which contacts the pawls for 
urging the pawls into gear engagement. 
The present invention is arranged wherein the assembly screws are utilized 
for piloting the spring which extends from the screw heads and to the 
pivotal pawls for urging the pawls into engagement with the gear. One 
advantage is that the spring can be a flat or planar type spring which 
also has a curved end securely piloted or mounted relative to the tool. 
Another object of the invention is to provide a ratcheting mechanism which 
has both the structure and the process of making whereby the tool includes 
an actuator cap which covers an otherwise open end of the tool, and the 
pawls and the springs can be inserted in the open end when the cap is 
removed, and subsequently the affixing of the cap to the handle itself 
covers and contains the pawls and the springs. This facilitates assembly 
of the tool and also assures a reliability of operation. Thus, the 
arrangement is such that it clearly distinguishes from prior art examples, 
such as the first two aforementioned patents, in that it utilizes the 
actuator of the end-cover or cap type which encloses the mechanism 
relative to the handle itself. 
The open end of the handle receives an insert which is secured by screws 
that are then utilized to pilot the pawl springs.

DETAILED DESCRIPTION OF THE MECHANISM AND PROCESS OF MAKING SAME 
While the following description, and the drawings, are basically directed 
at the tool itself, one skilled in the art will readily understand the 
process for making the tool. 
FIGS. 1 and 2 show the exterior of the tool which includes a handle 10 and 
an actuator 11 which is in the form of a cup shape and is thus a cap which 
is movably or rotatably mounted on the left end of the handle 10, as 
viewed in FIG. 1. The tool may be a ratcheting screwdriver, and the 
ratcheting mechanism itself is capable of having the ratcheting mechanism 
selectively placed in either a neutral position where there is drive in 
both directions or in a reverse or forward direction where there is 
ratcheting when in those two directions. 
FIG. 3 shows a fragment of the handle 10 and it shows the actuator 11 
mounted on the end thereof with both parts being coaxial relative to the 
longitudinal axis A. The handle 10 has a circular cavity 12 exposed to the 
left end of the handle 10, as viewed in FIG. 3, and that cavity receives 
an insert member 13 which also has a cylindrical or circular portion 14 
received in the circular opening or cavity 12. A cylindrically-shaped gear 
16 is disposed within the cylindrical opening 17 of the insert 13 to be 
rotatable therein, and the gear has its own cylindrical cavity 18 which 
receives a working tool, such as the fragment of the screwdriver bit 19. 
The insert 13 is in the nature of a T-shape and has the enlarged end 21 
which covers gear teeth 22 on the external circumference thereof. Three 
cap screws 23 extend through respective screw holes 24 in the insert 13, 
and the screws extend into threaded holes 26 in the end of the handle 10 
to thus secure the insert 13 to the handle 10. 
The insert 13 and the actuator 11 have mating bayonet-type ribs 27 and 28, 
respectively, and these ribs interlock with each other when the cap 11 is 
moved onto the handle 10 and is slightly rotated for the bayonet type 
engagement. The insert 13 also carries a plunger 29 which is urged by a 
compression spring 31 into a groove 32 in the cap 11 to thus limit 
rotation of the cap 11 relative to the handle 10, such as seen by that 
groove 32 in FIG. 4. 
At this time it will also be mentioned that FIG. 3 shows the enlarged 
screw-head holes 33 which are defined by arcuate walls 34 in the insert 
13. As will be seen in FIG. 4, the walls 34 for the lower two screw holes 
33 are not completely circular but are more of only a semi-circular 
configuration for a purpose described later. Also, there are three such 
screws 23 and three enlarged screw-head holes 33 in the insert 13. Again, 
with reference to FIG. 4, there is thus a semi-circular space which is 
designated 36 between the lower two screw heads 23 and the screw-hole 
walls 34, and that space will be further referred to hereinafter. As shown 
in FIGS. 3 and 4, it is the upper screw 23 and its adjacent wall 34 that 
is seen in FIG. 3 and that is fully circular. For the two lower screws 23 
shown in FIG. 4, the holes are semi-circular. FIG. 3 shows a circular 
space 35 for the upper screw, and the lower two screw spaces 36 are 
similar in thickness but are semi-circular, but the space thickness is 
shown to be as about twice the thickness of the spring therein. 
Thus, FIG. 4 shows that the three screws 23 are not at equal 120 degree 
intervals, but the two lower screws 23 are closer together, and this 
provides for accommodation of the parts of this mechanism. 
The insert 13 presents two pawl pockets 37 and 38 which are of an arcuate 
shape. Two pins 39 and 41 are affixed to the insert 13 and extend in the 
pockets 37 and 38 and they respectively receive pivotal pawls 42 and 43. 
It will also be noticed that the pawls 42 and 43 include a generally 
circular portion coxial to the respective pins 39 and 41 and they also 
have an extending finger portion 44 and 46 respectively, which carry teeth 
47 and 48 for engagement with the gear teeth 22, such as shown with the 
pawl 43 in FIG. 4. 
The actuator 11 has two recesses or pockets 51 and 52 on the inner circular 
wall 54 thereof, and these pockets 51 and 52 alternately respectively 
align with and are disposed adjacent to the pawls 42 and 43 for receiving 
the corners 53 of the pawls and thereby allow the pawls to be in tooth 
engagement with the gear teeth 22, such as shown with the pawl 43. The 
arrangement of the pawl and the actuator is similar to that disclosed in 
U.S. Pat. No. 5,619,891. 
FIGS. 4 and 7, 8, and 9 show the arrangement of the pawl-urging springs 56 
which are piloted on the two lower screws 23 as seen in FIG. 4. The 
springs 56 have a semi-circular portion 57 which conforms and fits into 
the space 36 between the screw heads 23 and the screw hole wall 34, as 
described with FIG. 3. The drawings further show that the springs 56 
include the straight or planar portion 58 which extends from the screw 
heads 23 and into contact with the pawl ends 44 and 46, respectively. The 
pawls 42 and 43 have corners 59 which receive the tips of the springs, as 
seen with pawls 43. In that manner, the springs 56 are controlled or 
trapped at both ends thereof, and they are therefore secure and operable 
for the purposes intended for moving the respective pawls into tooth 
engagement with the gear teeth 22 when the pawl corners 53 are disposed in 
the respective actuator pockets 51 and 52. 
In the arrangement described, the springs 56 can be easily assembled as a 
part of the ratcheting mechanism and when the cap or actuator 11 is not 
yet in position. In that manner, any unskilled laborer can perform the 
assembly, and there is no possibility of erroneous assembly. The screw 
holes 33 and pawl pockets 37 have a clear opening therebetween on the 
insert 13 so that the springs 56 can extend between the screw head 
openings and the pockets, as shown. For instance, the insert wall portions 
designated 61 make the openings extending between those two hole locations 
mentioned. 
In the process of making the tool, all of the operable parts, such as seen 
in FIG. 4, are positioned in the tool, including the springs 56, and this 
is done by moving those parts parallel to the longitudinal axis A, that 
is, by simply inserting them into the cavities in the end of the handle 
10, as described. Finally, the mounting of the actuator 11 on the handle 
10 covers the end openings and encloses the pawls and springs and the gear 
16 in the tool, in the secure and enclosed manner. No special spring 
mounting holes nor any special spring covering is required in order to 
simply set the springs 56 onto the screw heads 23 and have the springs 
extending to operative contact with the respective pawls, as shown. 
Likewise, insert 13 is made, then axially assembled. 
The spring 56, in its side view, as seen in FIG. 8, is in the shape of a 
question mark(?) or a hook. Its free-body portion 57 is shown to include 
an arcuate portion between points B and C, a straight portion between 
points C and D, and a straight portion between points B and E, and a 
straight portion between points F and G. The spring is of a resilient, 
spring material, and it thus flexes and recovers its shape. In the 
installed position shown in FIG. 4, the spring 56 is flexed to conform to 
the cylindrical shape of the screw head 23 for at least 200 degrees, so it 
is bound into the arcuate space 36 and is immovable when installed. So in 
the stalled position shown in FIG. 4, the spring is pre-stressed but 
easily installed by finger gripping. 
The gear 16 also has a square opening 62 for receiving a mating square end 
of the end 63 of the bit 19 for rotational drive therebetween. Also, the 
insert 13 has openings 64 therein in which the pawls 42 and 43 extend for 
engagement with the gear teeth 22. 
Thus the insert 13 can be specially made and then is affixed with the 
handle portion 10 by the cap screws 23 which also are employed for the 
mounting of the springs 56. All is assembled in movement along the axis A 
for easy assembly and compactness and sturdiness of the mechanism. 
The insert 13 and the assembly of the pins 39 and 41 which are pressed into 
the insert pin holes 66 and 67 can be made separate from the handle 10, 
The insert material, such as stainless steel can be employed while the 
handle 10 can be of aluminum and its silicone cover at 68 can be applied 
while the handle 10 is separate from the remainder of the tool. That 
arrangement is of further importance because the tool is useful in medical 
operations where sterilizing is required. U.S. Pat. No. 5,551,323 shows 
the silicone cover and that disclaimer is incorporated herein by reference 
to it, 
The insert 13 is then moved into the handle cavity 12, the screws 23 are 
applied, and then the pawls 42 and 43 and the springs 56 can be easily 
installed, all that assembly occurring in the longitudinal axial direction 
along axis A. The cap 11 is positioned over the handle end and it presents 
ribs 28 which engage ribs 27 on the insert for a bayonet type connection, 
as disclosed in U.S. application Ser. No, 08/796,632 filed Feb. 7, 1997 
and which is a part of this disclosure by this reference thereto. 
In the piloting of the springs 56, the spring ends 58 abut flat walls 71 on 
the insert 13 so the springs 56 are respectively secure in position and 
properly force on the pawls 42 and 43. Springs 56 thus have arcuate 
portions 57 and planar opposite end portions 58 and 60. Portion 60 is flat 
against the insert wall 71 defined by the insert upstanding portion 
designated 72. Thus the springs 56 are securely trapped between the insert 
walls and the screw heads 23, and the springs are under tension in that 
position so they cannot slide around the screw heads 23. 
In the process of making, the handle cover 68 is molded before the insert 
is affixed. Thus the insert is not subjected to the molding process.