Silent ratchet

A ratchet is provided in which a friction brake ring is employed to engage a pawl with the ratchet teeth in an annular ring or hinge extending from a ratchet tool handle. The friction brake ring carries the pawl into engagement when the tool handle is rotated in the direction in which it is desired to turn a workpiece. A spring within the ratchet returns the pawl to a position in which it is disengaged entirely when pressure on the tool handle in the rotational direction of engagement is released. Thus, the return of the tool handle before a subsequent engaging stroke is accomplished silently and without the characteristic clicking of the ratchet teeth of the hinge passing over the pawl.

FIELD OF THE INVENTION 
This invention relates to a ratcheting tool for use as a hand tool for 
socket wrenches and the like. 
Ratcheting tools have been used extensively as hand tools in association 
with socket wrenches and other mechanical adapters for engaging various 
types to workpieces. Conventional ratchet tools, however, have one 
characteristic in common. During return of the ratchet tool handle 
following a power stroke to turn a workpiece, the ratchet teeth of the 
annular ring or hinge at the end of the work handle produce a 
characteristic clicking sound as they pass over the teeth of a pawl 
located within the ratchet head. While for most operations this clicking 
is not particularly objectionable, there are certain instances where it is 
highly desirably to eliminate this characteristic noise of conventional 
ratchet tools. One application where the suppression of such noise is 
extremely important, for example, is in military vessels, especially 
submarines and other subsurface craft. In these applications, small sounds 
travel extensively in water and can be picked up by enemy sound detection 
equipment. Consequently, the elimination of even minor noises, such as the 
clicking of a ratchet tool, is highly desirable. 
The operating principle of a hand held ratchet tool is that a rotational 
force is exerted on a lever arm in the form of a work handle to exert 
torque on a workpiece. The torsional force acts about the same axis as the 
axis of rotation of the work handle. Ratchet tools are designed for 
reversible engagement. That is, rotation of the work handle in one 
direction will cause engagement of mating ratchet teeth within the ratchet 
tool to transmit torque to a workpiece. Counter-rotation of the work 
handle will disengage the ratchet teeth so that the work handle merely 
backs up for subsequent forward rotation in the direction in which it is 
desired to turn the workpiece. As previously noted, it is the backing up 
of the ratchet handle that results in the characteristic clicking noise in 
conventional ratchet tools. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a ratchet tool which 
can be used to engage and turn a workpiece in silence. It is particularly 
desirable to eliminate the characteristic clicking sound of conventional 
ratchet devices employed as socket wrenches screw drivers, and the like. 
The invention may be more clearly explained by reference to the 
accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION 
Refering now to FIG. 1 there is illustrated a ratchet tool 10. The ratchet 
tool 10 includes a work handle having a knurled grip 38, and a shank 37 
terminating in an annular ring or hinge 15. The annular ring 15 has an 
interior surface divided into a friction bearing section 40 and a toothed 
section 34 coaxial therewith. The section 34 is equipped with radially 
interiorally directed ratchet teet 45. Conversely, the bearing surface 40 
is relatively smooth, although it is not greased or lubricated since it is 
important that this surface provide some degree of friction. 
Adjacent to the annular ring 15 is a torque transmitting member 16 which is 
rotatable about its own axis. The torque transmitting member has one 
element 11 shaped to engage a workpiece, typically a socket from a socket 
wrench set. The torque transmitting member 16 also has a coaxial driver 
element 17 defined in the shape of a cylinder longitudinally disected by 
an axially extending planar bearing wall 36. This cross sectional 
configuration of the coaxial driver element 17 is best illustrated in 
FIGS. 3, 4 and 5. The driver element 17 has an intermediate neck section 
19 of reduced cross sectional area. Above the neck section 19 is a larger 
disk shaped section 18. A transverse channel 20 passes laterally through 
the disk shaped section 18 and bisects its upper surface. 
A detent means is located within the channel 20 and if formed with two 
spheres 21 positioned at opposite ends of the channel 20. The spheres 21 
are separated from each other and biased radially outward from the driver 
element 17 by means of a compressed spring 22 located in the channel 20. 
The annular ring 15, or hinge as it is sometimes called, encircles the 
driver element 17 so that the ring 15 and the driver element 17 are 
positioned in mutually coaxial arrangement to define a cavity between the 
interior surfaces of the ring and the planar bearing wall 36. 
A pawl 41 is located within the cavity and has an arcuate surface equipped 
with ratchet teeth 35. These ratchet teeth 35 of the pawl 41 are 
engageable with the ratchet teeth 45 of the annular ring 15 at the toothed 
section 34 thereof. Opposite the arcuate section of the pawl 41 containing 
the teeth 35 there is an opposing bearing surface of overall convex 
configuration. This bearing surface is formed of a planar interior segment 
30 flanked by planar end segments 29 and 31. Each of the segments 29, 30 
and 31 is alternatively positionable in contact with the planar bearing 
wall 36. The ratchet teeth 35 of the pawl 41 may thereby be alternatively 
engaged with the ratchet teeth 45 on the ring 15 for clockwise and 
counterclockwise rotation of the ring 15. More specifically, the pawl 41 
is engaged for counterclockwise rotation when it is in the position 
indicated in FIG. 3 with the planar end segment 31 in contact with the 
planar bearing wall 36. Conversely, the pawl 41 is engaged for clockwise 
rotation when in the position depicted in FIG. 5 with the planar end 
segment 29 in contact with the planar bearing wall 36. When the pawl 41 is 
in the position indicated in FIG. 4 the teeth 35 are totally disengaged 
from the teeth 45 of the annular ring 15. In this intermediate position, 
the pawl 41 lies with its planar interior segment 30 positioned in contact 
with the planar bearing wall 36. The teeth 45 of the toothed section 34 of 
the annular ring 15 do not ratchet pass the pawl 41 when the pawl 41 is in 
this intermediate position. Rather, there is total clearance between the 
teeth as illustrated so that the annular ring 15 rotates silently relative 
to the pawl 41 when the pawl 41 is in this intermediate position. 
An actuating pin 26 extends upwardly in a longitudinal direction from the 
pawl 41. A friction brake ring 24 encircles the greater portion of the 
driver element 17 at the neck section 19 thereof. Preferably, the friction 
brake ring 24 forms an arc of about 350.degree. about the driver element 
17, as illustrated. The friction brake ring 24 is biased radially outward 
against the friction bearing section 40 of the annular ring 15. The 
friction brake ring 24 passes atop the pawl 41 and above the toothed 
section 34 of the annular ring 15. The ends of the friction brake ring 24 
terminate in inwardly extending flanges 27 and 28 bracketing the actuating 
pin 26. 
A directional indexing member 14 is positioned in annular disposition about 
the driver element 17. In the indexing member 14 two sets of opposing 
radially extending detent depression are formed. These depressions are 
coplanar with the transverse channel 20 extending across the upper surface 
of the section 18 of the driver element 17. Two detent spheres 21 are 
designed to extend into these depressions when both of the depressions in 
a set in the annular indexing member 14 are aligned with the channel 20. 
Thus, the indexing member 14 may be rotated to one of two indexing 
positions. These two positions are the positions of relative rotation of 
the indexing member 14 at which the sets of detent depressions are aligned 
with and adjacent to the channel 20 in the driver element 17. The spheres 
21 are biased into engagement with depressions aligned therewith by the 
spring 22. Thus, the spheres 21 tend to hold the indexing member 14 in one 
of the two indexing positions. 
Two engagements protrusions 32 and 33 are spaced from each other and are 
carried by the indexing member 14. These engagement protrusions 32 and 33 
extend from the indexing member 14 for selective lateral engagement with 
the flanges 27 and 28 of the brake ring 24 to limit the rotational 
movement of the brake ring 24 relative to the indexing member 14. 
A spring means 25 is located within the annular space around the driver 
element 17 which exists by virtue of the neck section 19 of the driver 
element 17. The spring 25 is an arcuate spring fastened to one side of the 
driver element 17 and extending to beyond the opposite side thereof, to 
pass across the plane of the planar bearing wall 36 where it is fastened 
to the pawl 41. The spring 25 is designed to urge the pawl 41 toward the 
intermediate position of FIG. 4. 
The various operational elements of the ratchet tool 10 are held together 
by a cap 12 through which machine screws 13 extend for secured engagement 
with the driver element 17. 
In the operation of the invention, if it is desired to engage a workpiece 
on the element 11 of the torque transmitting member 16 for rotation in a 
counterclockwise direction, the annular indexing member 14 is rotated 
counterclockwise. With sufficient counterclockwise rotation, the annular 
indexing member 14 is secured in position by engagement of the spheres 21 
with corresponding depressions in the annular indexing member 14. At this 
point, the protrusions 32 and 33 extending toward the pawl 41 from the 
indexing member 14 are in the position indicated in FIGS. 3 and 4. The 
annular ring 15 is then rotated by means of the work handle in a 
counterclockwise direction. The friction brake ring 24 is carried with the 
annular ring 15 by virtue of the frictional forces that act between the 
friction brake ring 24 and the friction bearing section 40 of the annular 
ring 15. As the friction brake ring 24 is rotated in a counterclockwise 
direction, the flange 28 engages the actuating pin 26 extending upward 
from the pawl 41. This engagement during continued rotation moves the pawl 
41 against the influence of the spring 25 from its intermediate postion in 
which the planar interior segment 30 rests against the planar bearing wall 
36, to a position for engagement in a counterclockwise direction of 
rotation as indicated in FIG. 3. In this position, the planar end surface 
31 of the pawl 41 rests against the planar bearing surface 36. Also in 
this position, the ratchet teeth 35 of the pawl 41 are engaged with the 
ratchet teeth 45 of the tooth section 34 of the annular ring 15. Further 
counterclockwise rotation of the annular ring 15 causes a counterclockwise 
rotation of the workpiece. 
When the handle terminating in the annular ring 15 is to be backed off or 
returned in preparation for a subsequent power stroke in the direction of 
engagement, the annular ring 15 is rotated in a clockwise direction. This 
clockwise rotation of the friction brake ring 24, which is initially 
carried with the annular ring 15, released the actuating pin 26 of the 
pawl 41. When the actuating pin 26 is released, the arcuate spring 25 
pulls the pawl 41 back to its intermediate position, as indicated in FIG. 
4. A continued clockwise rotation of the annular ring 15 brings the flange 
28 of the friction brake ring 24 into contact with the protrusion 32 
extending from the indexing member 14. The protrusions 32 and 33 from the 
indexing element 14 are held in position with respect to the driver 
element 17 by means of the detent mechanism previously described. 
Accordingly, continued clockwise rotation of the annular ring 15 results 
in the protrusion 32 engaging the flange 28 so that the friction brake 
ring 24 can no longer rotate in a clockwise direction. Thereafter, 
although the annular ring 15 may continue to be rotated in a clockwise 
direction, the friction brake ring 24 is held immobile with the friction 
bearing section 40 sliding across the outer surface of the ring 24. 
When the clockwise return stroke has been completed, a subsequent 
counterclockwise power stroke is initiated. This again causes the flange 
28 to force the actuating pin 26 counterclockwise so that the pawl 41 
again assumes the position of counterclockwise engagement depicted in FIG. 
3. The transition between the positions of FIGS. 3 and 4 is thus repeated 
for as many strokes as are required for the particular workpiece being 
rotated. 
When it is desired to index the ratchet tool of this invention for 
engagement during clockwise rotation, the indexing member 14 is rotated in 
a clockwise direction relative to the driver section 17. This disengages 
the spheres 21 from one set of detent depressions, and engages them in the 
other set of detent depressions once the indexing member 14 has been 
turned clockwise to a sufficient extent. When in this position, the 
protrusions 32 and 33 are in the positions depicted in FIG. 5. A clockwise 
rotation of the annular ring 15 with the indexing member 14 in this 
position results in the engagement of the actuating pin 26 by the flange 
27 of friction brake ring 24. This overcomes the bias of the spring 25 and 
causes the pawl 41 to assume the position indicated in FIG. 5, where it is 
engaged for clockwise rotation of the annular ring 15. Once the clockwise 
rotation of the annular ring has ceased and the counterclockwise return 
stroke is initiated, the flange 27 no longer holds the actuating pin 26 in 
the position of FIG. 5. Consequently, the spring 25 draws the pawl 41 back 
to its intermediate position of total disengagement of the teeth 35 of the 
pawl with respect to the teeth 45 of the annular ring 15. 
It can be seen that the angle through which the pawl 41 rotates in changing 
between an intermediate and an engaged position must not be to great or 
jamming of the pawl 41 within the cavity is likely to occur. Preferably, 
the angle between adjacent planar segments of the bearing surface of the 
pawl is between about 2.degree. and 10.degree.. The preferred angle of 
alignment of adjacent ones of the segments 29,30, and 31 is about 
5.degree.. 
The foregoing description and illustration of the embodiment of the silent 
ratchet tool of this invention which has been depicted should not be 
considered as limiting in scope. Rather, the scope of the invention is 
defined in the claims which are appended hereto.