Improvements in and connected with Keys for Shafts.
Year: 1889

page_text: Date of Application, 18th July, 1889
Complete Specification Left, 17th Apr., 1890-Accepted, 17th May, 1890
PROVISIONAL SPECIFICATION.
Improvements in and connected with Keys for Shafts.
GEORGE RICHARDS of Altrincham in the county of Cheshire, Engineer, do hereby
declare the nature of this invention to be as follows:-
The object of this invention is to provide a cheaper and more rapid means of
inserting keys into shafts for driving. It refers to a method of preparing the keys,
and to a machine for making a recess into the shaft for receiving the keys.
The machine for preparing the recess in the shaft is arranged with a rotating
spindle, in which a cutter is attached, and advanced into the shaft. The spindle bas
a movement to produce recesses of different lengths and my improvements relate to
a method of producing these lengths of the recesses to fixed dimensions, so as to
interchange with the improved keys.
The movements referred to are produced by cams arranged in a series, one cam
only is employed according to size of key to be inserted.
The keys I prepare as follows.
A rectangular bar whose thickness equals the width of the key, and breadth equals
the length of the key, is prepared by rolling, drawing, or other well known
methods.
The bar has its edges of a semicircular shape. These bars after being prepared
in this manner are cut off, either by saws or other well known means, into short
lengths which form a key of rectangular section with the ends rounded.
The ends of the key thus correspond with the shape of the recess in which the ends
are left circular by a rotating cutter.
This system of producing keys, enables me to make a key that can be inserted
deeper into the shaft without extra expense. A very desirable object is gained by
having the keys deeper, inasmuch as the keys can be narrower and smaller thus
leaving the shaft stronger in the cross section.
T
171
11. 1000
GEO. RICHARDS.
COMPLETE SPECIFICATION.
Improvements in and connected with Keys for Shafts.
I, GEORGE RICHARDS of Altrincham in the County of Cheshire, 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:
The object of this Invention is to provide a cheaper and more rapid means of
inserting keys into shafts for driving. It refers to a method of preparing the keys,
and to a machine for making key seats or recesses into the shafts for receiving
the keys.
The machine for preparing the recess in the shaft is arranged with a rotating
spindle in which a cutter is attached, and advanced into the shaft. The spindle.bas
a movement to produce recesses of different lengths and my improvements relato to
a method of producing these lengths of the recesses to fixed dimensions, so as to
interchange with the improved keys. The movements referred to are produced by
cams arranged in a series, one can only is employed according to the size of key to
be inserted. The keys I prepare as follows.
A bar of metal, preferably of steel "ab" Fig. 1. whose thickness "c" Fig. 2
equals the width of the key, and its breadth "W" Fig. 1 equals the length of the
key, is prepared by rolling drawing or other well known methods.

page_text: The bar has its edges of a semicircular shape. These bars after being prepared in
this manner are cut off, either by saws, or other well known means, into short
lengths which form keys of rectangular section with the ends rounded.
The ends of the key thus correspond with shape of the recess in which the ends
are left semicircular by a rotating cutter.
This system of producing keys enables me to make a key that can be inserted
deeper than usual into the shaft without extra expense. A very desirable object is
gained by having the keys deeper, inasmuch as the keys can be narrower and smaller,
thus leaving the shaft stronger in the cross section.
Figures 14, 15, 16, 17 and 18, show various methods of applying the keys in
fastening pulleys on shafts.
The machine for making the key seats or recesses in the shaft is shown in
Figures 3, 4, 5, 6. The machine operates with rotary tools similar to those in general
use for this purpose.
There are various forms of machines in use that will prepare the recesses
suitable for the reception of the keys, but in order to accomplish the desired
object of cheapening and simplifying the process known as keying work in machine
manufacture, a special modification of the inachine is made.
The sizes of the keys used are determined by the movements of the machine, as
will be explained. The machine for making the recesses is automatic in its action
and differs principally from ordinary forms of such machines in having a regulated
traverse movement of the spindle, and also in obtaining this movement by means of
cams, so that by the use of a small number of cams recesses can be produced suitable
for a wide range of keys to suit different diameters of shafts.
It will be seen by reference to Fig. 7 that the shape of the cams is such as to
produce a uniform rate of movement to the cutter spindle. This is a very desirable
object in the use of such recessing tools, and has a particular reference to the rapid
cutting of the recesses. It will also be understood that the length of the recess in
the shaft is equal to the stroke of the cam plus the diameter of the cutting tool,
therefore one particular cam will produce recesses of different lengths according to
the diameter of the cutter. To make this more explicit, we will suppose that the
movement produced by the cam is 1 inch, then a cutter inch in diameter will
produce a recess 14 inch long, while a cutter inch in diameter will produce with the
same cam a recess 14 inch long, and a inch cutter will produce a recess 1 inches
long. This is shown clearly in Fig. 8 in which S is the stroke of the slide carrying
the spindle while W, W, W, are the lengths of the recessos.
The considerable number of key seats of different sizes capable of being produced
by a small number of cams is another feature of simplicity and cheapness in the
improved system.
The automatic machine referred to has also special features relating to the method
of accurately producing the required depth of the recess without skill on the part of
the attendant.
The depth of the recess is regulated by the width of the key, which is the thickness
of the prepared bar. The wider and stronger the key the greater should be its depth
in the shaft. This depth is irrespective of the length of the key, therefore the
number of cams required to produce the penetrating feed of the cutter into the shaft
is reduced to a few. In practice I propose to use nineteen sizes of keys to cover the
range of shafts from one inch to five inches diameter, and as only seven widths of
keys are used the positive penetrating or feeding-in motion of the tool requires only
seven cams. The cam for feeding-in is shown in Fig. 9. The cams are of such shape
as to produce different rates of movement of the slide carrying the spindle. The cam
acts against a roller R. When the roller is in the position shown at A Fig. 9 the
cutter is in the position relative to the shaft as shown in Fig. 10. As the cam
revolves and during part of its rotation from A to B, the cutter is brought into the
position shown in Fig. 11 when the cutting edges of the cutter approach the shaft
so as to slightly mark it. During that part of its rotation from B to C there is no
forward movement of the cutter, as this part of the cam is concentric. That part of

page_text: the cam from C to 1 gives the penetrating feed to the spindle, and advances the
cutter into the position shown in Fig. 12. When it has reached this point, the shape
of the cam allows the weight D in Fig. 4 to rapidly withdraw the spindle into the
position shown in Fig. 13 which is the same as in the first position shown in
Fig. 10.
The shaft in which the recess is being made is held in a circular chuck mounted
on a slide with a traversing motion by rack and pinion. This slide is placed at an
angle so that the lubricating material fed onto the cutter will drain into the main
frame of the machine. The motions of the reciprocating cams and feeding-in cams
are produced by the shaft S. Fig. 5. connected with the driving shaft by bevel
gears.
The object of the automatic recessing machine is to produce key seats or recesses
of positive dimensions which correspond with the sections of the bars from which the
keys are made.
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 1
claim is:
1. The system of keying shafts which consists in making sets of keys of various
sizes, but all of each set to be of the same size so as to be interchangeable, in com-
bination with the making by automatic or other machinery, of key seats of sizes to
correspond with the sets of keys, so that all the keys of any set will fit accurately
any of the corresponding key seats, substantially as described.
into
2. In combination with the above system of keying shafts the application of a
machine for making key seats in which the traverse of a rotary cutter is regulated
by a series of cams so as to produce recesses of various sizes, each cam corresponding
to the size of one set of keys.
3. In combination with the above system of keying shafts the making of sets of
keys of interchangeably accurate sizes, by having metal bars rolled drawn hammered
or otherwise made of the proper cross section, and cutting off short lengths of such
bars corresponding to the depth of insertion of the key into the shaft and into the
boss, while the breadth of the bar forms the length of the key, and the thickness of
the bar forms the thickness of the key, substantially as described.
4. In combination with the above system of keying shafts a machine for making
key seats of interchangeably accurate sizes, substantially as described.
Dated this Sixteenth day of April 1890.
GEO. RICHARDS.