Year: 1887

page_text: Date of Application, 23rd Aug., 1887
Specification Accepted, 11th Oct., 1887.
I, WILLIAM N. WOODRUFF, of Hartford, Connecticut, one of the United States of
America, machinist, 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 those parts of machines usually denominated keys,"
and which are employed for holding gears, wheels or other details of machines, in
fixed circumferential position on their supporting shafts.
The object of the invention is to furnish a key of that class, which shall be more
economical to manufacture, more convenient to apply, and more efficient in use than
those heretofore known.
Fig. 1, of the accompanying sheet of drawings, is a side elevation of a shaft
and key relating to my improvement. Fig. 2 is a cross-sectional view of the same on
line aa, Fig. Fig. 3 is a view similar to Fig. 1, showing the shaft cut away to
line bb, Fig. 2, and showing a section of a gear fitted on the shaft, over the key,
and also showing the projecting end of the shaft of equal diameter with that part
carrying the key on the wheel. Fig. 4 illustrates the preferable mode of forming
the rest for the key. Fig. 5 shows, in side and edge view, a blank from which to
make the keys. Fig. 6 shows, in side and end view, a key made from said blank.
The shaft S is similar to the shafts commonly used in a variety of machines, as
for instance, in lathes and other metal-working machines, and in weaving and other
textile machinery. Said shaft. is to have fitted thereto some part of machinery, as
for instance, the gear or other wheel G, which may or may not be set against a
shoulder, 2, formed on the shaft. The wheel-carrying portion, 3, of shaft S, has
formed therein, and longitudinally thereof, a key-seat which is a circular-arc concavity
throughout its length, as shown by the lower part of the dotted circle 4, in Fig. 1,
and by the solid line 5, in Fig. 3. Into this key-seat, the key N is inserted, its
two opposite sides being parallel planes; its lower edge being formed convex to
conform to the concavity of the key-seat; and its straight upper edge projecting
above the shaft a proper distance, to fit an ordinary key-way formed in the wheel or
other part fitted on the shaft.

page_text: The parts being thus constructed, when the wheel G is put on, as in Fig. 3, and
forcibly if necessary, the key N readily rocks in its concave seat 5, until the upper
edge of said key conforms, in its position, to the upper edge 6, of the key-way in
said wheel; and this whether said upper edge is parallel to said shaft, or is inclined
thereto as shown by dotted line c c. Thus is my improvement specially adapted for
holding change-wheels which, while at first sliding on freely, should be driven firmly
on the key, as they come against the shoulder 2.
For forming the key-seat in the shaft, I employ a milling cutter, 8, Fig. 4, corre-
sponding in its thickness to that of the key N, and in its radius to that of the
circle 4, Fig. 1. This cutter being carried by a suitable revolving stem or spindle, as
9, it is fed into the shaft to the required depth, thereby finishing the key-seat by a
single operation, of a very inexpensive character. By the old mode of making key-
seats, several distinct operations are necessary, involving much greater expense than
by my method.
The saving thus effected will amount in the aggregate to a large
sum, where machines of the classes specified are produced in large numbers.
The manufacture of the keys of proper, size and shape may be accomplished as
follows: A disk or blank, D, Fig. 5, is first prepared, of the diameter and thickness
of the cutter, 8, which is used for cutting out the key-seat. This blank is next
divided on lines 7, 7, thereby making two keys of those parts, 10, 10, which lie
outside of said lines. By cutting out the central space 12 of the proper width, the
keys are made of the required height, and appear as shown in Fig. 6. When
longer keys of less height are required, larger blanks D are used, and in some cases
three or more keys may be cut from the same blank.
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 I claim is :
The combination herein described, the same consisting in a shaft having longi-
tudinally thereof a key-seat, concaved substantially as described; a part fitting said
shaft, and having a key-way; and a key lying in said key-seat, one edge of said key
being formed convex to fit the concavity of the key-seat, and the other edge thereof
being fitted to the key-way in said part, substantially as described.
Dated this Twenty sixth day of July 1887.
WILLIAM N. WOODRUFF.