Year: 1886

page_text: Date of Application, 2nd Oct., 1886.
Complete Left, 2nd July, 1887.
Complete Accepted, 16th Aug., 1887.
DCO
I, HERBERT ARTHUR COUCHMAN, of 7 Stanley Villas, Pembury Road, Tottenham, in
the County of Middlesex, Engineer do hereby declare the nature of this invention to
be as follows:-
This invention relates to that description of spanner in which one of the jaws is
adapted to slide on the stock or stem on the end of which the second or fixed jaw, or
head, is formed, thus rendering the spanner adjustable. My present invention
consists of the following simple and inexpensive arrangements for rendering the sliding
jaw easily adjustable in relation to the fixed jaw or head.
.
On the underside of the said sliding jaw, I form a suitably shaped recess, or
chamber, into which I fit a pawl. One end of this pawl is centred on a pin which
passes through the sides of the said recess or chamber, the other end extending to the
face of the stock or stem. The adjacent surfaces of the stock or stem and the pawl are
preferably serrated in order to prevent slipping. The outer end of the pawl is
provided with a finger or catch by which it may be placed in or out of contact with the
stock or stem, and it may be held in either position by means of a spring acting on
one of two flats formed on the back end of the said pawl. Or, instead of the
finger or catch being formed with or attached to the pawl, the latter may be keyed,
or otherwise similarly fitted, to the pin which carries it, the said pin being shaped
into or provided with a cranked handle or lever which may be arranged to lie along
the side of the sliding jaw.
In order to open the spanner the required distance, the pawl is drawn back free
of the stock or stem by the finger, catch, or crank, and the sliding jaw may then
be adjusted to the required distance or gap. The pawl is then returned by the
finger, catch, or crank into its former position, so that its serrated end is in contact
with the serrated surface of the stock or stem, and the spanner is then ready for use.
Dated this 2nd day of October 1886
H. A. COUCHMAN.
Per W. H. Beck,
115, Cannon Street, London,
Agent.

page_text: I, HERBERT ARTHUR COUCHMAN, of 17, Devonshire Street, Liverpool Street, in the
City of London, Engineer, 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 that description of moving spanner provided with two
jaws in which one of the latter, for the purposes of adjustment, is adapted to slide
on the stock or lever, the fixed jaw or head being formed at the extremity of the
said lever. The objects of the present invention are to provide simple and
inexpensive arrangements for rendering the jaws easily adjustable with relation to
one another.
In order that the invention may be readily understood, I will proceed to describe
the same with reference to the accompanying drawings, in which Figure 1 represents
in plan and Figure 2 in side elevation a spanner constructed according to my
improved method, Figure 3 showing a similar spanner provided with an additional
improvement hereinafter described. Like letters of reference are used to indicate
corresponding parts in all the Figures.
In the sliding jaw a, 1 pivot about a pin b a pawl c, which, by the action of the
spring d, is caused to bear against the face of the lever e; in order to create the
requisite friction between the surfaces of the pawl and of the lever which are or
may be in contact with each other, the end of the former and the face of the latter are
preferably notched or serrated, as indicated in Figure 2. The periphery of the
curved end of the pawl c is eccentric with reference to the centre of the pin b,
about which the said pawl is pivoted, so that, as the pressure on the moving jaw a increases,
the security of the hold between the pawl and the lever increases also. The proper
action of the pawl c depends upon the degree of eccentricity of the periphery of the
curved end c¹ as regards the centre of the pivot b, and also upon the extent to which
a line joining the centre of the pin 6 with the point of contact between the pawl and
the lever is out of the perpendicular with respect to the face of the said lever."
In order to allow the jaws to be withdrawn from each other, the pawl c is provided
with a projection c², by means of which the said pawl may be moved about its pivot
and the curved or acting end c¹ thrown out of action by being released from contact
with the face of the lever e; under the latter circumstances the spanner may be easily
adjusted. The sliding movement of the jaw a is limited by the stop e¹ in the lever e."
In carrying out this invention, I have found it is advantageous to employ a spring,
such as fin Figure 3, acting to force apart the two jaws, the manipulation of the
spanner being greatly facilitated by the use of such a device.
The pawl c may be held either in or out of action by allowing the spring d to act
upon one of two adjacent flats formed on the projection c². The pin 6 may be secured
to the pawl c and caused to move with it, in which case the projection c³ may be

page_text: dispensed with, and the said pawl may be operated by a crank or handle on the pivot-
pin b, which crank or handle may be arranged to lie in close proximity to and alongside
of the jaw a.
I do not limit myself to the particular form of pawl herein described and illustrated,
as the same may be varied without departing from the principle of the invention.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim in
respect of adjustable spanners is :
:―
1. A pawl pivoted in the sliding jaw and acting against the face of the lever for
the purpose of holding the said jaw in position, substantially as set forth.
2. In combination with a pawl pivoted in the sliding jaw, a spring adapted for
retaining the said pawl in the required position, substantially as set forth.
3. The combination with the lever e, provided with a fixed jaw or head, of a movable
jaw a, retained in position after adjustment by means of a pawl, substantially as set
forth.
4. The improved manufacture of adjustable spanner, substantially as described and
illustrated.