Improvements in Ball Bearing Scissors.
Year: 1899

page_text: Date of Application, 3rd Jan., 1899-Accepted, 2nd Sept., 1899
COMPLETE SPECIFICATION.
Improvements in Ball Bearing Scissors.
I, THOMAS MURPHY, of Sewickley, County of Allegheny, and State of Penn-
sylvania, U.S.A., do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in the following statement:
-
This invention relates to certain new and useful improvements in ball bearing
scissors, and has for its object to arrange a bearing whereby the two blades of
the scissors may be retained firmly in their respective positions to each other,
and the loosening of the joint, so common with the ordinary scissors, be obviated.
The principal features of my invention reside in a washer which is retained
by the head of the screw which fastens the two blades together, the said washer
being provided on its underneath face with a circumferential groove, which,
together with a similar groove formed in one of the blades of the shears act as
a race for the balls.
Through this arrangement the screw fastening the two blades together may be
kept tightly adjusted, and a greater bearing surface is provided on the outer
face of the blade to accomplish the aforesaid result, while the balls interposed
between the washer and the outer face of the blade will serve to reduce the
friction that would otherwise be caused through the tightening of the screw.
With the above and other objects in view, the invention finally consists in
the novel construction, combination and arrangement of parts to be hereinafter
more specifically described and particularly pointed out in the claims.
In describing the invention in detail reference is had to the accompanying
drawings forming a part of this specification and wherein like letters of refer-
ence indicate similar parts throughout the several views thereof, in which: —
Figure 1, is a perspective view of a pair of shears, partly broken away, the
same being constructed in accordance with my invention.
Figure 2, is a side view of a portion of the shears, partly in section, to show
the arrangement of the bearing.
Figure 3, is a top plan view of a portion of the blade, in which the circum-
ferential groove that forms a part of the ball race is arranged.
Figure 4, is an underneath plan view of the washer.
Referring now to the drawings by reference letters a and a¹, represent the
respective blades of the scissors, which may of course be of any desired form or
shape. These two blades are secured together by means of the pivotal screw c,
having a suitable head c¹, and upon which is arranged between the said head c¹,
and the blade a, a washer d, which is provided on its underneath face with a
circumferential groove d, that forms half of the race for the balls e, the other
portion of said race being formed of a circumferential groove f, that is arranged
on the outer face of the blade a, around the hole in said blade which receives the
pivotal screw.
The portion of the pivotal screw that engages in the blade a, and which receives
the washer, is smooth on its periphery, while that portion that engages the

page_text: blade a¹, is provided with a thread 2, to secure the screw in position. The
operation of the device is clear without further description.
The heretofore described arrangement constitutes a ball bearing between the
washer, and the blade a, the said balls being interposed in this position, form-
ing a circumferential bearing, and thereby serving to hold the two blades in
their perfect relation to each other. The halls also act in the reducing of the
friction when the pivotal screw is tightened.
While the foregoing appear to embody the preferable form of my invention,
yet I do not wish to limit myself to this exact construction, as herein shown,
as various changes may be made in the details of construction without departing
from the general spirit of my invention.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
consider novel and desire to claim is: -
1. In combination, the shear half a, provided with a circumferential groove
forming a ball seat, the pivotal screw c, for fastening the halves and a' together,
the washer, which is provided on its underneath face with a circumferential
groove, and the balls arranged in said grooves in the washer and shear half a,
substantially as shown and described.
2. A ball bearing scissors, comprising the two halves a and a¹, the pivotal
screw by means of which the two halves are secured together, the washer carried
by said screw, said washer and the shear half a, provided with circumferential
grooves surrounding the pivotal screw, and forming a ball race for the balls
which are interposed in said grooves and rest between the washer and the shear
half substantially as shown and described.
1000
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.