Improvements in and connected with Holders for Taps or like Tools.
Year: 1893

page_text: Date of Application, 27th June, 1893-Accepted, 29th July, 1893
COMPLETE SPECIFICATION.
Improvements in and connected with Holders for Taps or
like Tools.
I, ALFRED AMES FISHER, of 471 Eighteenth Street, Brooklyn, State of New
York, United States of America, Manufacturer, 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 and by the following statement:-
My invention relates to means for securely holding taps and tools of a similar
nature, and it consists of the construction and combinations of devices which are
hereinafter fully described and claimed.
Referring to the accompanying drawing for a more complete explanation of the
invention,
Fig. 1 is a perspective view of the improved tap holder.
Fig. 2 is a longitudinal sectional view of the same.
Fig. 3 is a part elevation and part sectional view showing the tap holder attached
to a chuck.
Fig. 4 is a transverse sectional view on the line - of Fig. 2.
The object of my invention is to construct a holder for the reception of taps
and like tools for boring, tapping and drilling machines, and in which the body
piece of the holder is adapted to be fitted within the socket of a chuck fitted to a
driver. Another object is to locate the jaws of the tap holder so that they lie
within the plane of the ends of the body portion, thereby preventing the slotting
or grooving of the exterior face of the body, and preventing the production of
obstructions on the face of the body portion.
The invention is particularly well adapted for use in connection with a form of
chuck shown in Fig. 3 in which the inner end of the drive spindle is provided with
an enlarged head a suitably recessed to receive the inner end of the chuck; which
latter has a friction piece c which is made preferably of hard rubber, paper or
fibrous material secured to the squared end of the socket piece, and having edges
beveled or V-shaped in cross section and adapted to be frictionally held against
corresponding seats on the two main parts of the chuck the two parts being united
in a suitable way although the invention may be used with a different construction
of chuck.
Into the socket piece d of said head a, the square stem or shank A of the body
portion of the present tap holder is adapted to be inserted, said shank having at
its outer end an enlarged head B with smooth and unbroken outer face, except that
the central portion of it is pierced at B₁ to permit the insertion and withdrawal of
the tap or other tool.
At points between the front and rear faces of the head B, an opening C is made
through the walls thereof in planes at right angles to the tap opening B'. This
opening C is elongated and occupies the major portion of the head between its
front and rear faces but it terminates short of said faces whereby the outer face
preserves its smooth unbroken appearance, and a longer seat is provided for the
shank or stem of the tap. The opening has straight parallel side walls and rounded
ends, and within it the jaws D and E are inserted so that when the jaws are in
their normal closed condition, with the tap removed, the outer top walls of the
jaws are flush with the exterior sides of the head. The jaws correspond with the
shape of the opening C and the inner faces at one end are cut away or reduced to
form the offsets or bearings F for the operating screw, and the portions of the
inner faces of the jaws forward of these bearings or offsets are formed with

page_text: V-shaped grooves e adapted to securely grip the angular corners of the stem or
shank of the inserted tap.
The operating screw S passes entirely through the rear portions of the jaws,
and has at its middle portion the collar or flange G upon one side of which are
right hand threads while upon the opposite side are left hand threads, whereby
when the screw is turned by means of a suitable tool such as H, the jaws close or
open towards each other to adjust themselves to the size of the shank or stem of
the inserted tap, or to permit the latter to be removed.
Through one side of the body portion B, a hole 1 is made to intersect the
opening C in a plane at right angles to its major axis and the axis of the screw,
and within this opening a bearing block 1. is inserted having a grooved inner face
adapted to receive the collar or flange G; and upon the back of this block La
screw M is adapted to bear to adjust the grooved face of the block against the
flange or collar G to form a close bearing therewith and to be adjusted to take up
any wear between the collar or flange and block. When the jaws are closed the
space left by their reduced rear ends receives the inwardly projecting block L
which enables the jaws to close tightly without obstruction.
A tap holder of the form described and shown is very simple in its construction,
dispensing with all face grooving, and as the opening in which the jaws slide is
made wholly within the exterior walls of the head, the jaws have a long and secure
bearing and are prevented from being injuriously affected by any twisting move-
ment applied to the point or front end of the strap.
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 :-
1st. In a tap or tool holder, the head portion thereof having an opening made
through its body portion at a point inside of its front and rear faces, jaws capable
of sliding in said opening, and a screw passing through the rear portion of the
opening and through the rear portions of the jaws, said screw having right and
left threads whereby the jaws move in opposite directions when the screw is turned,
substantially as herein described.
2nd. In a tap or tool holder the head portion thereof having a projecting stem
or shank at its rear and having a smooth front face pierced to receive the shank of
the tap, said head having an elongated opening made through it and having straight
parallel sides and curved ends, jaws corresponding with and adapted to be moved
in and out in said opening, and a screw passing through said jaws and opening and
having right and left threads whereby the jaws are operated, substantially as herein
described.
3rd. In a tap or tool holder the head portion having an opening through it at
points inside of its front and rear faces, jaws fitted to move in said opening and
having offsets or reduced portions at their rear ends, a right and left screw passing
through said offsets or reduced portions and through said opening, a collar or flange
on the middle portion of the screw, and a block adjustably mounted in said head
in a plane at right angles to the screw and having a grooved inner face to receive
said collar or flange, substantially as herein described.
4th. In a tap or tool holder, the combination with its head portion, its jaws, and
the screw for operating the jaws of the block mounted in the head at right angles
to the screw and adapted to engage the middle portion of the latter, and a screw
bearing against the block and adjusting it against the screw, substantially as herein
described.
5th. The combination with a chuck having a friction piece provided with a socket
piece, of a tap holder having a head portion, and a rearwardly extending stem or
shank adapted to fit said socket piece, jaws movable in said head at points between
its front and rear faces, a screw passing through said jaws and having right and
left threads by which the jaws are operated, said screw having a collar or flange

page_text: at its middle portion, and a block adjustably fitted in the head and engaging the
collar or flange, substantially as herein described.
Dated this 27th day of June 1893.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London,
Chartered Patent Agent for the Applicant.