mprovements in and relating to Anti-friction Screws and Nuts or Bearings therefor, applicable to Lifting Jacks, Screw Presses, and to other purposes.
Year: 1898

page_text: Date of Application, 29th Mar., 1898-Accepted, 24th Sept., 1898
COMPLETE SPECIFICATION.
mprovements in and relating to Anti-friction Screws and Nuts or
Bearings therefor, applicable to Lifting Jacks, Screw Presses, and
to other purposes.
I, HENRY MINOR STEVENSON, a Citizen of the United States of America, residing
t No. 601, North 5th Street, Perry, in the County of Dallas and State of Iowa,
United States of America, Manufacturer, do hereby declare the nature of this
nvention, and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:—
My invention has relation to improvements in anti-friction bearings for screw
powers, jacks and the like, and the object is to provide a simple, durable and
effective bearing of this class.
To this end the novelty consists in the construction, combination and arrange-
ment of the same, as will be hereinafter more fully described and particularly
pointed out in the claims.
In the accompanying drawing the same reference characters indicate the same
parts of the invention.
Figure 1 is a vertical section of a screw jack having my improved bearing
applied thereto.
Figure 2 is a transverse section of the same.
1 represents the socket, and 2 the cylindrical screw.
The screw 2 is provided with a semi-circular female thread 3, and the socket
is also provided with a corresponding semi-circular female thread 4, and 5 repre-
sents a lateral guide-way connecting the upper and lower ends of said thread 4
and forming a continuation thereof, so that practically it becomes a continuous or
endless thread.
6-6 represent a series of bearing balls completely and snugly filling the threads,
the screw and socket and also the lateral guide-way 5, so that if the screw be
turned to the left to elevate it, the balls will leave the upper end of the thread
and pass into the upper end of the lateral passage and out at the lower end and
into the thread again.
This operation is reversed when the screw is lowered, and thus it will be seen
that in either case a continuous anti-friction track or bearing is formed for the
0 threads in the screw and socket.
While I have illustrated my invention as applied to a screw jack, I do not
wish to be understood as confining myself to such use, as it is equally applicable
to all forms of power presses, and in fact, anywhere where a screw power is used.
Although I have specifically described the construction and relative arrange-
5 ment of the several elements of my invention, I do not desire to be confined to the
same, as such changes or modifications may be made as clearly fall within the
scope of my invention without departing from the spirit thereof.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim, is;—
1. A screw-shaft provided with a semi-circular female thread, in combination
with an endless ball bearing track, as and for the purpose set forth.
2. The screw-shaft 2, provided with the semi-circular female thread 3, and
the socket 1 formed with the corresponding semi-circular thread 4, in combination
with the series of bearing balls 6--6 engaging said threads jointly, as and for the
purpose set forth.
3. The cylindrical shaft 2, provided with the semi-circular female thread 3, the
socket 1 provided with the semi-circular female thread 4, and the lateral guide-
way connecting the opposite ends of said thread 4, in combination with a con-
tinuous series of bearing balls 6 arranged in said threads, substantially as shown
and described.
Dated this Twenty ninth dor of Manch 1000
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.