IMPROVEMENTS " IN KEYS OR WEDGES
Year: 1882

page_text: LETTERS PATENT to John Henry Johnson of 47 Lincolns Inn Fields in
the County of Middlesex, Gentleman for an Invention of "IMPROVEMENTS
"
IN KEYS OR WEDGES communicated to him from Eugène Charles Edouard
Gallois a person resident at Paris in the Republic of France.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 14th December 1882.
"
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex,
Gentleman, "IMPROVEMENTS IN KEYS OR WEDGES a communication to me from
Eugène Charles Edouard Gallois, a person resident at Paris in the Republic of
France,
This Invention relates to improvements in keys or wedges to be employed for
fixing wheels or pulleys on shafting and for other purposes where a similar keying
or wedging action required, and it has for its object to produce a key capable of
being placed in position without violence and of being subsequently jammed or
made tight as hereinafter described and which also shall not be liable to get loose
accidentally although capable of being removed with facility when required.
The main part or body of the improved key is of the ordinary form and of
dimensions corresponding to the purpose to which it is to be applied. On its upper
side is formed a longitudinal groove or recess in which is lodged a bar or rod
capable of sliding longitudinally therein. This rod is flattened for the greater part
of its length and is provided at one end with a screw and at the other end with a
wedge shaped enlargement. A dovetailed or grooved recess is formed across the
head of the key for the reception of a nut having a collar which engages with the
groove or dovetail being slipped into position from one side of the head and retained
by an abutting screw or other suitable means. The upper surface of the key is
composed of a plate hinged to the head of the key and resting on the rod. The
screwed end of the rod works in the nut so that when the latter is rotated the rod
is caused to slide longitudinally in the key and by means of its wedge shaped
enlargement either pushes the plate away from the other part of the key or the
reverse thus tightening or loosening the key.

page_text: The key thus constituted is placed in the groove or key-way provided for its
reception, the nut is then turned so as to draw up the rod and cause the wedge-
shaped enlargement on the end of the latter to push the plate away from the main
part of the key, thus jamming the latter as tightly as may be desired.
It will be observed that the nut is entirely free from any liability to work loose
(if necessary a lock nut or other locking device may be applied to the nut on the
rod) consequently accidental loosening of the key becomes impossible.
In order to remove the key the nut must be turned in the opposite direction to
that in which it was turned when tightening the key.-This causes the wedge to
recede thus allowing the hinged plate to approach the body of the key and the
latter may then be removed without being subjected to violence or injury.
The improved key is applicable to the fixing of toothed gear, pulleys, sleeves
collars and the like upon shafting and in general to all purposes for which keys
are usually employed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Henry Johnson in the Great Seal Patent Office on the
13th June 1883.
"
"
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman IMPROVEMENTS IN KEYS OR WEDGES a communication to me from
Eugène Charles Edouard Gallois a person resident at Paris in the Republic of
France
This Invention relates to improvements in keys or wedges to be employed for
fixing wheels or pulleys on shafting and for other purposes where a similar keying
or wedging action is required and it has for its object to produce an expanding key
which is capable of being easily placed in position and of being subsequently
jammed or made tight as hereinafter described and which also shall not be liable
to get loose accidentally although capable of being removed with facility when
required.
And in order that the 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 corresponding figures.
Figure 1 of the accompanying drawings is a longitudinal section Figure 2 is a
plan and figures 3 and 4 are respectively end elevations at opposite ends of a key
constructed according to this invention
Figure 5 is a longitudinal section and figures 6 and 7 are end views representing
a modified form of the improved key or wedge as hereinafter described..
The main part or body A of the improved key as shewn in figures 1 to 4 is of
the ordinary form and of dimensions corresponding to the purpose to which it is to
be applied and is provided with a head D which may be of the usual shape-On
the upper side of the main or body part A is formed a longitudinal groove or
recess b (figure 3) in which is lodged a bar or rod B capable of sliding longitudinally
therein. This rod B is flattened for the greater part of its length to fit the said
recess b and is provided at one end (which is rounded) with a screw c (passing
through a hole in the head D) and at the other end with a wedge shaped enlarge-
ment C. A dovetailed undercut or grooved recess 6¹ is formed across the head of
the key for the reception of a nut E having a collar or shoulder e which engages
with the groove or dovetail b' being slipped into position from one side of the head
and retained if necessary by a screw or other suitable means not shewn in the
drawing-The upper surface of the key is composed of a plate F hinged to the head
of the key at f and resting on the rod B and wedge shaped enlargement C. The
screwed end c of this rod works in the nut E so that when the said nut E is rotated
in one direction the key is expanded and tightened by the action of the wedge
shaped enlargement C pushing out the plate away from the body part A of the
key and when the said nut is turned in the opposite direction the wedge shaped
enlargement C is moved back so as to allow the plate F to return to its former
position and thus loosen the key.
•
In order to put the parts of the key together the hinged plate F is placed in
position the collar on the nut E is slipped into the recess 6' in the head D and the
rod B with the wedge C are put in place in the body of the key the screw c on the
said rod being caused to engage with the nut E.
The key thus constituted is placed in the groove or key way provided for its
reception. the nut E is then turned so as to draw up the rod B and cause the
wedge shaped enlargement C to push the plate F away from the main part A of

page_text: the key as indicated by the dotted lines in figure 1 thus jamming the latter firmly
in position.
It will be observed that the nut E is not liable to work loose but if desired a
lock nut or other locking device may be applied to the said nut E to prevent any
possibility of the accidental loosening of the key.
In order to remove. the key the nut E must be turned in the opposite direction
to that in which it was turned when expanding or tightening the key. This causes
the wedge shaped enlargement C to recede thus allowing the hinged plate F to
approach the body A of the key and the key may then be removed without being
subjected to violence or injury.
Figures 5, 6 and 7 are respectively a longitudinal section and elevations at
opposite ends of a modified construction of the said key or wedge..
The key arranged according to this modification is capable of being readily.
tightened or loosened and is intended more particularly to be applied to keying
heavy work such as large fly wheels which are to rotate at a high speed-The key
in this modification is also constructed with a body part A provided with a head D
which may be of the usual form and having therein a groove b for the reception of
a corresponding projection c¹ on a wedge shaped piece C connected to a screw c
working in a nut E-The body part A is inclined on its upper side on which
incline the wedge shaped piece slides An undercut recess b¹ in the lead D
serves to connect the latter with a shoulder or collar e formed on the nut E and
working loosely in the said recess b¹. A hole o is provided in the head D for the.
passage of the screw cand is made of an elongated or elliptical form in order to allow
for the rising movement of the wedge.
By turning the nut E in the proper direction the wedge-shaped piece C is drawn
up thereby expanding the key until it is jammed in place with a most powerful
wedging action which is exerted along the whole length of the key the opposite
sides of which may be always parallel. In order to loosen the key the nut is turned'
in the opposite direction so as to cause the wedge shaped piece C to slide down the
inclined surface on the body part A.
1
The improved key constructed according to this invention is capable of being
inserted and withdrawn with great facility and expedition without sudden strains
at the same time producing a most effectual wedging action and may be employed
with great advantage for securing toothed wheels, drums, collars and the like upon
shafting and in general for all similar purposes for which keys or wedges are or may
be employed.
"1
Having now described and particularly ascertained the nature of. the 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 :-
Providing keys or wedges with means for expanding them for fixing them firmly
in place and for contracting them for their release substantially as hereinbefore
described and illustrated in the accompanying drawings
In witness whereof I the said John Henry Johnson have to this my Specifi-,
cation set my band and seal this eighth day of June One thousand eight
hundred and eighty three.
J. HENRY. JOHNSON (L.S:)