Improvements in and in Connection with Screw Drivers and like
Year: 1886

page_text: Date of Application, 26th Mar., 1886.
-Complete. Left, 23rd Dec., 1886.
Complete Accepted, 25th Jan., 1887.
[Communicated from abroad by ZACHARY T. FURBISH, of Augusta, in the State of
Maine, in the United States of America, Mechanic.]
Improvements in and in Connection with Screw Drivers and like
I, ARTHUR WILLIAM TIPPER, of 22 Lidfield Road, Green Lanes, London, in the
County of Middlesex, Gentleman do hereby declare the nature of the said invention
to be as follows:-
This Invention relates to screw drivers and other tools of that type in which the
tool can be turned intermittently by the hand of the user without loosening the grasp
from the handle of the tool, and the Invention consists in the special construction and
arrangement of the parts being the connections between the shank and the handle.
The handle is hollow and is provided with a cylindrical metal chamber covered by a
suitable head or end piece. The shank of the tool passes through the hollow handle
into the metal chamber where it is provided with and firmly attached to a disc having
a corrugated periphery and is free to turn in the metal chamber. On one side of the
inner periphery of the metal chamber there is a cam projection and between the
corrugated disc and this cam projection there are two pins which are kept in position
by a flat spring which encircles the disc and bears against the two pins, so that the
two pins bind between the corrugated disc and the cam projection and the tool is thus
prevented from turning in either direction. Over the corrugated disc there is a shunt
plate having a projection which comes between the two binding pins. This shunt plate
also has a projection which comes through a notched recess in the metal chamber and
so that it will take into one of such notches. The notches are three in number and
when the projection from the shunt plate is in the central notch, the pins bind the tool
and the handle together in such a manner that the tool and the handle when turned in
either direction move together as one. By moving the shunt plate so that its projection
comes into one of the side notches, the projection from the shunt plate which comes
between the binding pins, forces the pin on that side clear of the projecting cam piece,

page_text: so that the handle is free to turn independently of the corrugated disc and tool in one
direction, while the other pin binds the handle and corrugated disc together when
turned in the other direction, thus by moving the shunt plate to the right, or to the
left and fixing it there by the notch, the handle and tool will move together when
turned in one direction and the handle is free to turn independently of the tool when
moved in the other direction. To keep the shunt plate in position, it is centred on
a projecting portion of the tool shank, which is continued through the corrugated
disc for that purpose. To keep the shunt plate in position bearing against the
corrugated disc, there is a plate spring, and over this plate spring, the head, or end
piece of the handle ships, and is secured to the metal chamber by lugs, or screws.
The device according to this Invention is applicable to tools, such as screw drivers,
boring bits, sprig bits, gimlets and the like, and where great power is required, the
metal chamber may be provided with a lever handle. The tool shank may also have
an enlargement provided with a socket and set screw to receive various sizes and
kinds of screw drivers, boring bits, or like tools.

page_text: or suitable device to the shank B there is provided a power disc c the periphery of
which is corrugated, or notched. This disc c is free to turn in the metal chamber with
the shank B. On one side of the inner surface of the metal chamber a there is a cam
projection d and between the periphery of the corrugated disc c and this cam projec-
tion d there are two pins e e¹ which are kept in position by a flat spring which
encircles the disc c, bears against, and causes the pins e e¹ in their normal position to
come between the corrugations of the disc c and the cam projection d in the manner
shown at Figure 4. Thereby the disc c the shank B the metal chamber a and the
handle A are locked and so the shank B and the handle A must turn together in
either direction. h is a shunt plate which is loosely mounted over the disc c on the
turned down portion b of the shank B. This shunt plate is provided with a
projection h¹ which comes between the two binding pins e e¹ and also with a projection h³
which comes through a notched recess at in the metal chamber a over the cam
projection d. This recess has three notches m l r so that when the projection h² of the
shunt plate is in the middle notch m as shown at Figure 4 the pins e e¹ are in their
normal position and the handle and shank turn together. When the projection h² of
the shunt plate his moved into the notch r, the shunt plate takes the position shown
in Figure 5 and the projection h¹ comes against the pins e and by pressing it to one
side against the spring fas shown, throws it out of gear with the disc c. Thus, when
turned to the right the handle and shank being still locked by the pin e¹ they turn
together, but when turned to the left by reason of the pin e having been thrown out of
gear with the disc the handle A is free to turn without moving the shank B. When
the projection h² of the shunt plate h is moved into the notch the shunt plate
takes the position shown at Figure 6 and the projection h¹ comes against the pin e
and by pressing it to one side against the spring f as shown, throws it out of gear
with the disc c, thus when turned to the left, the handle and shank being still locked
by the pin e, they turn together, but when turned to the right by reason of the pin e¹
being thrown out of gear with the disc, the handle A is free to turn without moving
the shank B. Thus by moving the shunt plate to the right, or to the left and
fixing it there by the projection * taking into the notches r or the screw driver can
be used to drive, or withdraw screws without taking the driving edge from the cross
cut of the screw head. To keep the shunt plate h in position bearing on the metal
chamber a there is provided a plate spring which bears against the shunt plate and
the inner side of the head, or end piece A².
It will of course be readily understood that the shank B may be provided with a
socket instead of a tool point and that different sizes and forms of tools may be applied
thereto, or fit therein, such as boring bits, sprig bits, screw drivers, and the like. The
metal chamber a may also be provided with a lever handle when more power is required.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I declare that what I claim is :-
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1. In screw drivers or tools of the type herein described the combination with the
power disc (c) thereof of a spring (f) and two rollers (e e¹), working between the
said power disc (c) and a cam projection (d), operating and arranged substantially as
set forth.
2. The combination of the handle (A) having a metal chamber (a) and end
cover (A2) as described, with the corrugated disc (c), shank (B), rollers (e e¹), cam (d),
spring (), shunt plate () and plate spring (p) arranged and operating substantially
as and for the purposes set forth.
3. The construction and arrangement of parts of the screw driver or like tool herein
set forth and illustrated in the Drawings.