Improvement in Saw-sharpening Machines.
Year: 1890

page_text: Date of Application, 7th Jan., 1890-Accepted, 8th Feb., 1890
COMPLETE SPECIFICATION.
Improvement in Saw-sharpening Machines.
LEWIS P. HALLADAY, of 1007 Opera House Block, Chicago, Illinois, United States
of America, Mechanical Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and ascer-
tained, in and by the following statement :-
My invention relates to improvement in saw sharpening machines and has for its
object to provide a machine in which the teeth will be properly ground.
1 accomplish this by means of the devices illustrated in the accompanying drawing
wherein,
Figure 1 is a front elevation of the arbor head, arbor and saw in position; and
Figure 2 is a detail showing the relation of tooth and grinding wheel in the old
form of the machine.
Like parts are indicated by the same letter in both figures.
A is the saw suitably held, B the grinding wheel on the arbor C. This arbor is
journalled in the bearings D D and carries the pulleys E E by which it is driven.
The wheel and arbor is supported on the sliding frame F, which is itself supported on
the tilting frame G. This latter frame is pivoted at H and adjustably supported by
the bolt which passes through the slot K, on the main frame L. The arbor is set
diagonally to the line of the motion of its sliding frame.
The use and operation of my invention are as follows;
In grinding saws wherein the side surface of the grinding wheel is parallel with the
plane of its motion, it apparent that in time there will be cut away a certain amount
of the grinding surface of such wheel about its edge to the average depth of the teeth
ground as indicated in figure 2. As this process continues the grinding wheel is
gradually unfitted for use and the teeth of the saw are gradually conformed to the
very undesirable shape shown in the left of figure 2. By setting the grinding wheel
at an angle other than a right angle to the line of its motion, it is easily seen as
indicated in figure 1 that the edge of the wheel is presented to and passes down along
the face of the teeth and that neither tooth nor wheel is injured. As the work of the
bevelled portion of the edge of the wheel is greater than that of the edge proper the
wheel will continue to retain a sharp edge and a bevel substantially as shown for an
indefinite period. The inclination of the wheel to the line of its motion can be greatly
varied.
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 :-
1. In a saw sharpening machine a grinding wheel set at an angle to the line of its
reciprocating motion, said angle acute toward the saw to be ground.
2. In a saw sharpening machine a grinding wheel in combination with a recipro-
cating frame on which it is supported, said grinding wheel set at an angle to the line
of the motion of said frame, said angle acute toward the saw to be ground.
3. In a saw sharpening machine a grinding wheel in combination with a recipro-
cating frame and an arbor on which such grinding wheel is fixed and which is itself
set diagonally on such reciprocating frame, the grinding wheel at an angle to the
reciprocating frame, said angle acute toward the saw to be ground.
4. In a saw sharpening machine a grinding wheel in combination with a recipro-
cating frame which moves at an angle to the axis of the saw, and an arbor which
carries the grinding wheel and which is set at an angle to the axis of the saw and is
supported on the moving frame.

page_text: 5. In a saw sharpening machine a grinding wheel in combination with a frame
which is adapted to reciprocate at an angle to the axis of the saw and an arbor
supported diagonally on such frame and carrying the grinding wheel, the latter set at
an angle to the frame, said angle acute toward the saw to be ground.
Dated this 7th day of January 1890
FREDERIC PRINCE,
1, Quality Court, Chancery Lane, London, Agent for Applicant.