Universal joint embodying oscillating drive pin

A universal joint having a socket and a ball engaged in a bore of the socket, a pair of diametrically opposing slots in the socket wall, a socket driving pin extending through the ball and having its ends extending beyond the ball into said respective slots and being adapted to oscillate therein, and a device associated with the ball and socket to retain the ball in the socket. The pin and ball or the pin and slots are adapted for relative rotation.

BACKGROUND OF THE INVENTION 
The invention relates to universal joints usable for tools, such as 
wrenches, in which the two ends of the tool may be misaligned within 
limited angular positions with respect to each other. 
In the prior art, universal joints typically used in tools have been 
expensive and difficult to manufacture, and also have been difficult to 
disassemble and reassemble to replace worn parts. 
Another problem of great importance in the prior art has been that the 
balls have been made to be weak where the driving pin has been engaged 
therewith. The balls have been retained in the sockets by securing the 
pins in the socket walls and this has required enlarged, weakening 
openings in the balls to permit relative movement of the ball and socket. 
Further, additional means have been required to secure the pins in the 
sockets. 
SUMMARY OF THE INVENTION 
The present invention provides a universal joint in which the drive pin 
extending through the ball is not fixed in the socket but is free to 
oscillate with the ball in the socket during normal operation. Because 
there is no tendency to pull the ball and socket apart, they are held 
together in a simple manner which does not require securing the pin to the 
socket. 
Accordingly, it is an object of the invention to provide an improved 
universal joint. 
It is another object of the invention to provide a universal joint which is 
strengthened in the area where the ball extends through the pin. This is 
where most breakage occurs in prior art universal joints. By arranging the 
ball and pin in the socket so that the pin is not the means to secure the 
ball therein, the foregoing strengthening of the ball and pin area is 
accomplished. 
It is still another object of the invention to provide a universal joint 
which is simple and inexpensive to manufacture, and is also simple to 
assemble and disassemble to permit easy and rapid replacement of worn 
parts. 
It is a further object of the invention to provide a universal joint in 
which the torque acts on thicker and stronger ball-pin portions than in 
the prior art. 
It is a still further object of the invention to provide a universal joint 
in which the drive pin and the ball oscillate in the socket, the pin 
sliding in slots therein. The pin can be made to rotate in the ball or in 
the slots. 
It is another object of the invention to provide a universal joint in which 
the pin is maintained for rotation in the ball by simple and lightweight 
structures, and which are not required to be of great strength. 
It is still another object of the invention to provide a universal joint in 
which the ball is snugly fitted within the socket to avoid any floppiness 
between the two parts. This is accomplished by relatively weak and 
lightweight parts. 
It is a further object of the invention to provide a universal joint having 
a sleeve on the socket to retain the pin in the ball, and which sleeve 
permits the socket to be made having a thinner wall. 
Further objects and advantages of the invention may be brought out in the 
following part of the specification wherein small details have been 
described for the competence of disclosure, without intending to limit the 
scope of the invention which is set forth in the appended claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring again to the drawings, there is shown in FIGS. 1-4 a universal 
joint, generally designated as 10, comprised of a socket 12 and a ball 14. 
The socket has a rectangular shank 16 at its outer end, the shank having a 
typical spring biased, depressible tool engaging detent 18. 
The socket has an exterior cylindrical surface 20 and has in its inner end 
a cylindrical bore 22 having a substantially spherical bottom 24. In 
communication with the bore are diametrically opposed slots 30 and 32 in 
the wall of the socket. The slots have rearwardly tapering limiting 
surfaces 34 and 36, respectively. Extending inwardly from the bottom 24 of 
the bore 22 is a small diameter bore 40 containing a coil spring 42 in 
abutment with the inner end of the ball 14. 
The ball is substantially spherical so as to fit for rotation within the 
bore 22 and has two flat faces 44 and 46 facing the respective slots 30 
and 32. A bore 48 extends diametrically through the ball and fitted for 
rotation therein is a cylindrical drive pin 50 extending into the slots. A 
longitudinally centered, annular groove 52 is cut into the pin. Transverse 
to the annular groove is a diametrical bore 56 extending through the ball, 
interrupted by the bore 48, and in alignment with the groove 52. The bore 
56 extends slightly beyond the ball into a shank 60 connected thereto. 
A spring 62 abuts the bottom of the bore 56 and its other end abuts a ball 
64 therein, and biases it into the annular groove 52 so as to retain the 
pin in the ball. 
The pin 50 has pairs of parallel flat sides 66, 68 and 70, 72 adjacent its 
opposite ends in slidable engagement with the respective slots. The flat 
sides terminate inwardly at the cylindrical part of the pin in shoulders 
74, 76 and 78, 80, which also serve to retain the pin within the ball when 
it is in the socket. The tips of the pin have convex surfaces 84 and 86 so 
that when they are oscillated they do not extend beyond the slots 30 and 
32. 
As shown in FIG. 2, a set screw 90 is threadedly engaged in the wall of the 
socket and protrudes inwardly to be in contact with the ball outwardly of 
its center to retain it in the socket. The set screw 90 and the spring 42 
hold the ball snugly within the socket so as to provide a frictional fit 
to prevent the socket from flopping with respect to the ball. Such a fit 
is preferable in universal joints used with air impact tools. 
Connected to the shank 60 is a cylindrical member 94 having an axially 
directed, rectangular central opening 96 in its outer end and a transverse 
bore 98 at right angles thereto. The bore 96 is adapted to receive a 
shank, as 16, having a detent 18 to be engaged in the bore 98. 
In operation, the pin 50 and the ball 14 are adapted to oscillate in the 
socket into variations of positions as shown in the phantom outline in 
FIG. 1 when there is rotation in the direction of the slots, the flat 
sides of the pin sliding on the surfaces thereof. The oscillating travel 
of the cylindrical member 94 and ball is indicated by the arrows 100, 102 
which extend through arcs of the order of 25.degree. in each direction, 
limited by surfaces 34 and 36. Most relative movement of the ball and 
socket also includes rotation of the ball on the pin. During axial 
rotation of the joint, the ball through the drive pin 50 drives the socket 
12. 
The joint is assembled by inserting the spring 62 into the bore 56 with the 
ball 60 thereon and the pin is then moved into the bore 48 holding the 
ball against the spring. When the groove 52 is moved into alignment with 
the ball the spring snaps the ball into the groove so as to lock the pin 
in the ball. 
With the spring 42 in the bore 40, the ball is moved into the socket, and 
the pin is moved into the slots. Thus, it is clear that the assembly and 
disassembly are very simple and provide for easy exchange of worn parts. 
In addition, the structure provides a large mass of ball around the pin so 
as to provide great strength in that area, which is where breakage 
typically occurs in the prior art universal joints. 
In FIGS. 5-7 another embodiment of the invention is illustrated. Here, the 
universal joint, generally designated as 110, is formed of a socket 112 
and a ball 114. The socket has a shank 16 in the same manner as the 
embodiment of FIG. 1. The cylindrical socket has diametrically opposed 
slots 118 and 120 and a central cylindrical bore 124 of the same general 
configuration as in the other embodiment. The cylindrical bore 124 
terminates in a generally spherical bottom 126. Surrounding the socket is 
a sleeve 122 which may be securedly fitted on the socket or integral 
therewith. Added strength of the sleeve permits the wall of the socket to 
be of a thinner structure than that shown in FIG. 1. A cylindrical drive 
pin 128 is tightly fitted within a diametrical bore 130 in the ball so as 
to be rotatable therewith, the ends of the pin being slidably and 
rotatably engaged in the slots 118, 120. The tips 132 and 134 of the pin 
are convex so as to permit oscillation of the pins within the socket 
without making contact with the sleeve. 
Here, again, the ball has a large mass around the pin. Connected to the 
ball is a shank 140 on which there is a cylindrical tool receiving member 
142 of the same type as 94 in FIG. 1. 
In this embodiment the ball is snugly held within the socket by means of a 
spring 144 in an angular bore 146 through the wall of the socket, the 
inner end of the spring being in abutment with the ball outwardly of its 
center and the outer end of the spring being in abutment with a disc 148. 
The snugness of the ball within the socket is adjusted by means of a set 
screw 150 acting on the disc 148 and being accessible through a bore 152 
extending through the sleeve. In operation, in this embodiment, most 
relative rotation of the ball and socket causes the drive pin to oscillate 
as well as to rotate in the slots, the ball respectively oscillating and 
rotating in the socket. 
The invention and its attendant advantages will be understood from the 
foregoing description and it will be apparent that various changes may be 
made in the form, construction and arrangements of the parts of the 
invention without departing from the spirit and scope thereof or 
sacrificing its material advantages, the arrangements hereinbefore 
described being merely by way of example. I do not wish to be restricted 
to the specific forms shown or uses mentioned except as defined in the 
accompanying claims, wherein various portions have been separated for 
clarity of reading and not for emphasis.