Improvements in or relating to Catches for Retaining the Handles of Machines in Position.
Year: 1896

page_text: Date of Application, 9th Mar., 1896-Accepted, 9th May, 1896
COMPLETE SPECIFICATION.
Improvements in or relating to Catches for Retaining the Handles
of Machines in Position.
I, WILLIAM KIRKLEY BIRKINSHAW of Old Croft House, Quarndon, Derby, in
the County of Derby, Merchant, 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:-
This invention relates to catches for retaining the removable handles of machines
in position, so that they are not liable when the machine is in motion to fly off the
rotating shaft on which they are placed. For example it is applicable with great
advantage to cranes, to hold the crane handle in place.
In the Specification of prior Letters Patent No. 1975* 1890 granted to Heard &
Birkinshaw are descriptions and illustrations of catches for a like purpose,.
constructed with clips or equivalent devices which encircle and grip the shaft upon
which the removable handle is to be retained by a claw or the like forming part.
of the catch.
It is found, however, that on the shafts of many machines there is room only for
the socket of the removable handle, no space being available for clips of the kind
above referred to. According to the present invention catches for retaining handles.
on shafts are provided with means enabling them to be secured in position in the
desired proximity to the shaft without encircling the latter; for instance, the catch
may be so constructed that it may be readily secured to the face of the boss of a
wheel or pulley keyed on the shaft, or secured to a radial extension from the shaft
such as the arm of a pulley or the like.
In the accompanying drawings which illustrate one construction of catch
according to this invention.
Figure 1 is a perspective view of a catch in place on the boss of a wheel and
Figure 2 is a view, of a plate forming part of Figure 1 and hereinafter more
particularly referred to.
A is a shaft with a squared end adapted to receive the boss B 1 of a removable
handle B. C is a wheel keyed upon the shaft with its own boss C 1 in such close
proximity to the squared shaft end as to leave insufficient room for anything of the
nature of clip around the shaft between the boss B 1 of the handle and the
adjacent boss C i of the wheel. D is a spring-controlled clawjadapted to engage with
the handle boss B 1 as shown, in the manner described in the aforesaid Specification
of prior Letters Patent. This claw D is pivotted at D1 to the plate E, which
forms the body, or stationary portion of the catch, and is screwed to the face of the
boss C 1 by screws E 1.
The plate E can if desired be cut away as at E 2 to engage part of the squared
shaft end A, if there is sufficient space for the plate E to extend down between the
bosses B1 and C 1.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is ;-
1. A catch for a crane handle or the like, adapted to be secured upon a flat
surface such as a wheel-boss or on an arm or bar turning with the shaft substantially
as and for the purpose described.

page_text: 2. The catch for a crane handle or the like, substantially as and for the purpose
described and illustrated in the accompanying drawings.
Dated this 7th day of March 1896.
W. K. BIRKINSHAW.
Boult & Wade,
Agents for the Applicant.