Improvements in Blade Grinders.
Year: 1898

page_text: [Communicated from abroad by THE SINGER MANUFACTURING COMPANY, of New
York, United States of America, Sewing Machine Manufacturers.]
Improvements in Blade Grinders.
I, WILLIAM HARVEY INSLEE, Manager of The Singer Manufacturing Company,
Kilbowie, Dumbartonshire, do hereby declare the nature of this invention and in
what manner the same is to be performed as communicated to me, to be particularly
described and ascertained in and by the following statement:-
This invention relates to a grinder more especially intended for sharpening the
shear blades of sewing machine trimmers, although adapted for other purposes.
The shear trimmer blades, for sharpening which my improved grinder is more
particularly designed, are, when in use, pivotally mounted, so that when adjusted
to compensate for wear they are simply turned on their pivots, and it is therefore
essential that the cutting edges thereof should always preserve certain tangential
lines relative to their pivotal centres, as also that the bevels of their edges should
always preserve certain angles, all of which objects are so reliably secured by my
improved grinding device that it is practically impossible for unskilled operators,
in the use of my invention, to grind the blades wrong.
Figure 1 is a plan view of my improved grinder, and Figures 2 and 3 are side
and end views, respectively, of the same.
A denotes a base-plate, to be attached to a work-bench or table, and 13 is a
standard adjustably secured to said base-plate and provided with bearing arms
or portions b. C is a shaft journalled in the bearing arms 6 and provided at one
end with a driving pulley c and at its opposite end with an emery or other suitable
grinding wheel D clamped to said shaft in any well-known manner.
The base-plate A is provided with longitudinal ribs or guide-ways a on which is
mounted a sliding carriage having an inclined face against which is placed the
blade, as F, to be sharpened. The guide-ways a are parallel to the line of the
longitudinal axis of the shaft C so that the carriage E is movable back and forth
on said guide-ways in a plane transverse to the plane of rotation of the grinding
wheel D carried by said shaft, when a blade is being sharpened. G is a screw
tapped in the carriage E and having a milled or other suitable head by which it
may be readily turned. The segmental blade F is provided with a hole (for its
pivotal mounting when in use) through which the stem of the screw G passes so
that the said blade is thereby pivotally mounted on said screw. The blade Fis
preferably yieldingly held against the inclined face of the carriage E by a spring H
interposed between the head of the screw G and the said blade. G' is an adjusting
screw tapped in a portion e of the carriage E, the lower end of said screw impinging
against the blade F, so that by turning said screw said blade will be turned slightly
on the screw G as a pivot to bring the tangentially arranged cutting edge f of the
said blade against the grinding wheel D.

page_text: In the use of the grinder the attendant mounts the blade to be ground on the
carriage, as shown, and then adjusts the screw G¹ to bring the edge f of the blade
against the revolving grinding wheel. The carriage E is now moved back and
forth by the attendant in its guide-ways a and the screw G¹ turned down until the
desired sharpness of edge is secured. The inclined position of the blade holding
part of the carriage and the certain guiding of the latter on its ways insure an
even bevel and a uniform straight, tangential form and disposition of the cutting
edge of the blade being ground, and it will therefore be practically impossible for
the most unskilled attendant to grind the blades wrong.
As the grinding wheel wears away the standard B may be adjusted forward, or
towards the blade F, as may be necessary.
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 grinder, the combination with a suitable base provided with a guide-
way or guide-ways, of a sliding carriage mounted thereon and having an inclined
blade-supporting part, means for pivotally mounting a blade to be ground on said
inclined blade-supporting part of said carriage, a rotating grinding wheel, and a
screw adjusting device for forcing the edge of the pivotally mounted blade to be
ground into proper grinding contact with said wheel, the said carriage, with the
pivotally mounted blade, being movable back and forth on said guide-ways in a
plane transverse to the plane of rotation of said grinding wheel.
2. In a grinder, the combination with a suitable base provided with a guide-
way or guide-ways, of a sliding carriage mounted thereon and having an inclined
blade-supporting part, means for pivotally and yieldingly mounting a blade to be
ground on said inclined blade-supporting part of said carriage a rotating grinding
wheel, and a screw adjusting-device for forcing the edge of the pivotally mounted
blade to be ground into proper grinding contact with said wheel.
3. The combination with the base A provided with the ribs or guide-ways a, of
the standard B adjustably mounted on said base, the shaft C journalled in said:
standard and provided with the driving pulley e and the grinding wheel D), and
the sliding carriage E movable on said guide-ways in a plane transverse to the
plane of rotation of said grinding wheel, said carriage having an inclined blade-
supporting face provided with the blade-holding pivot screw G and blade adjusting
screw G¹.
3
4. The combination with the base A provided with the ribs or guideways a, of
the standard B adjustably mounted on said base, the shaft C journalled in said
standard and provided with the driving pulley c and the grinding wheel D, and
the liding carriage E movable on said guideways and having an inclined blade-
supporting face provided with the blade-holding pivot screw G and blade adjusting 4
screw G¹, said blade-holding screw being encircled by a spiral spring to yieldingly
press the blade being ground against said grinding wheel.
Dated this 31st day of January 1898