IMPROVEMENTS IN SECURING THE BLADES OF SHEARS TO THEIR SHANKS AND Bows.
Year: 1879

page_text: LETTERS PATENT to James Rimmer, of Sheffield, in the County of York,
Engineer, for the Invention of "IMPROVEMENTS IN SECURING THE BLADES
OF SHEARS TO THEIR SHANKS AND Bows.".
Sealed the 27th April 1880, and dated the 31st October 1879.
PROVISIONAL SPECIFICATION left by the said James Rimmer at the Office
of the Commissioners of Patents on the 31st October 1879.
"IMPROVEMENTS
JAMES RIMMER, of Sheffield, in the County of York, Engineer.
IN SECURING THE BLADES OF SHEARS TO THEIR SHANKS AND BOWS."
My Invention relates to improvements in the method of securing the blades of
shears to their shanks and bows, and more especially to those shears the blades of
which are removeable, so that they may be easily taken out to be sharpened when
dull or replaced with new ones when worn out, and its object is to provide a secure,
durable, and inexpensive fastening to attach the blades to their shanks or bows,
and I accomplish this object in the following manner, that is say:-In the manu-
facture of sheep shears, for example, I make the blades of the ordinary shape but
provided with a shank or tang, having a projecting piece or catch on one of its
edges. The shanks and bow are made very similar to the usual shape, and in the
hollow of the shank I fit a short metal block provided with a hole or slot to receive
the tang of the blade; it is also provided with two cross slots, one to receive the
projecting piece or catch on the shank or tang of the blade, and the other to receive
a similar catch formed on the edge of a key or cotter; this catch is to prevent the
key or cotter from slipping out of the slot and being lost.
I put a key or cotter in the slot of the block, letting the catch fall into the cross
slot; there is sufficient room now to pass in the tang of the blade, and its catch
must also be dropped into the remaining cross slot; the key or cotter is then
slightly raised when it can be driven forward and secured by keys, the tang of the
blade between the sides of the metal block thus effectually securing the blade in its
place; a solid or split pin or similar device may be used for the more effectually
preventing the key from being lost. A modification of my Invention may be made
by constructing the shank of malleable cast iron or other suitable metal, in which
case the before mentioned block is cast in one piece with the shank. The shanks
are then secured to the bow by means of rivets or other similar means.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Rimmer in the Great Seal Patent Office on the 30th April
1880.
JAMES RIMMER, of Sheffield, in the County of York, Engineer.
IN SECURING THE BLADES OF SHEARS TO THEIR SHANKS AND BOWS."
"IMPROVEMENTS
My said Invention relates to improvements in the method of securing the blades
of shears to their shanks and bows, and has reference to that description of shears
the blades of which are removeable, so that they may be easily taken out to be
sharpened when dull or replaced with new ones when worn out; and the Invention
consists of an arrangement of fastening for attaching the blades to their shanks
which is secure, durable, and inexpensive, and at the same time adınits of the blades
being readily removed and replaced.
In carrying out my said Invention as applied to the manufacture of sheep shears,
for example, I make the blades of the ordinary shape, but provided with a shank
or tang having a projecting piece or catch formed on its back. The shanks, which
are also made very similar to the usual shape are bent into a semicircular section,
and into the recess thus formed is fitted securely a short socket piece which is
provided with a longitudinal slot to receive the tang of the blade, and a key or
cotter or somewhat similar slot is made at right angles with the first named slot to
admit on one side the projecting piece or catch on the back of the tang, and on the
other side to admit a stop formed in the key for the purposes hereinafter described.
By driving the key forward into the socket the tang of the blade is thereby
securely wedged within the said socket, so that the blades of the shears are rigidly
attached to their shanks and bow, the blades being again released by a reverse
motion of the key.
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings; the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawing represents a pair of shears more
especially adapted for shearing sheep, and which have the attachment of the blades
to their shanks and spring bow constructed according to iny said Invention;
Figure 2 represents a portion of a blade detached from its shank; and the other
Figures also represent different parts of my improved shears which are hereinafter
referred to.
A are the blades, which are each constructed with a tang a (Figure 2) which is
formed with a projecting piece or catch a¹ on its back; B (Figure 1) are the shanks
connected by means of the spring bow band bent into a semicircular shape, as
shewn in cross section in Figure 3. Into the hollow thus formed in the shank is
fitted a short socket piece C, shewn in the complete view Figure 1, in side elevation
in Figure 4, in longitudinal section in Figure 5, and in end elevation in Figure 6;
the said socket piece which is perfectly made of malleable cast iron is rivetted to
the shank, as indicated in Figure 1, the rivets c being shewn clearly in Figures 1,
4, 5, and 6. The socket is provided with a longitudinal slot c' for the reception of
the tang a of the blade A and a key or cotter D, as shewn in Figures 5 and 6.
A somewhat similar slot c², Figure 5, is made at right angles with the slot c¹ to
admit on one side the projecting piece or catch a', on the back of the tang a of
the blade, and on the other side to admit a stop d formed on the key D, the said
stop being provided for the double purpose of preventing the key from slipping out
of the socket and being lost, and as a means whereby the key can be driven back
to release the tang of the blade when it is necessary to remove the blade from the
shank. The key D has a recess d¹ cut out of its face, as shewn in Figure 5 and in
dotted lines in Figure 1 in order that when the tang a of the blade is inserted in

page_text: the slot c¹ of the socket piece the key may be sufficiently out of the way to enable
the projecting piece or catch a¹ of the tang of the blade to enter the slot c¹ and fall
into the recess formed by the slot c²; the key D is then raised out of its recess and
driven forward, so that the deeper portions d² and ds of the key become the bearing
surfaces, and thus securely wedge the tang of the blade within the socket piece.
In order to more effectually secure the key in its place a solid or split pin or similar
device may be used.
The sectional view, Figure 5, shews the position of the wedge or key and the
tang of the blade when being placed in position and before the projecting piece
on the tang of the blade enters the recess c². Figure 1 represents the wedges
or keys in their normal position with the tangs of the blades secured to the
shanks.
A modification of the arrangement hereinbefore described may be made by con-
structing the socket piece and shank in one, and securing the shank to the bow by
means of rivets or other similar means.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,-
Securing the removable blades of shears to their shanks and bow by means of
socket pieces and keys or cotters, substantially in the manner and for the purposes
hereinbefore described.
In witness whereof, I, the said James Rimmer, have to this my Specification
set my hand and seal, this Twenty fourth day of April, One thousand eight
hundred and eighty
Witness,
F. T. DRURY.
JAMES RIMMER, (L.S.)
his x mark.