IMPROVEMENTS IN APPARATUS TO FACILITATE THE GRINDING AND SURFACING OF METALLIC AND OTHER BODIES
Year: 1874

page_text: LETTERS PATENT to Henry Gardner, of the Firm of Robertson,
Brooman, and Company, of 166, Fleet Street, in the City of London,
Patent Agents, for the Invention of "IMPROVEMENTS IN APPARATUS
TO FACILITATE THE GRINDING AND SURFACING OF METALLIC AND OTHER
BODIES." A communication from abroad by Louis Bollmann, a
Citizen of the United States of America, but residing at Vienna, in
the Empire of Austria.
PROVISIONAL SPECIFICATION left by the said Henry Gardner at
the Office of the Commissioners of Patents, with his Petition, on
the 11th September 1874.
:
I,. HENRY GARDNER, of the Firm of Robertson, Brooman, and Com-
pany, of 166, Fleet Street, in the City of London, Patent Agents, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
APPARATUS TO FACILITATE THE GRINDING AND SURFACING OF METALLIC AND OTHER
BODIES,” communicated to me from abroad by Louis Bollmann, a

page_text: Empire of Austria, to be as follows:―
The objects of this Invention are,-
Firstly. Placing the slide rest which carrics the work to be ground or
surfaced on a shaft in such a manner that by a swinging motion of the
latter the work can be brought near to or further from the emery or
other grinding or surfacing wheel.
Secondly. The employment of a brake in connection with a lever or
its equivalent to operate in such a manner that while the lever moves
the work in one direction the friction of the brake presses the work 1
against the emery wheel, while the opposite occurs when the work is
pushed back.
Thirdly. The employment of a balance spring (or its equivalent, a
weight) to balance the weight of a slide rest and the work.
Fourthly. To press the work against the emery wheel with a yielding 1
pressure.
Fifthly. To give to the slide rest a motion to the right or left on a
shaft by means of a lever or its equivalent.
Sixthly. Connecting guide bars to a table, and its action against rollers
for giving to the work the exact shape required.
1 Seventhly. The combination of a yielding slide rest with two emery
wheels on two independent spindles bearing in two swinging frames, the
two wheels being placed side by side, and one of them used for rough
grinding, while the other does the smooth finishing of the work, each of
them being capable of being raised or lowered to the work, as the a
difference of wear requires, by means of set screws, the two frames in
which the wheel spindles bear swinging on a shaft.
The Invention will be gathered from the following description of the
apparatus: A base plate supports an adjustable bracket on its front
face, and this bracket holds a table, a slide rest, and other appliances in
or by which the article to be ground or surfaced is held, the slide rest
with the appliances being capable of movement to the front and rear,
and also sideways, to bring the article under the action of a rotating disc
or wheel, by which the grinding, reducing, surfacing, polishing, or other
manipulation can be effected. The bracket carries a swing lever and a

page_text: diso, the latter being pressed upon by a spring and employed in con-
junction with a spring or a weight at the back of the. ápparatus, by
which an equilibrium or balance of the table and parts connected with it
can be effected. The bracket also carries a swivel arm, one end of which
can be regulated by a screw pin, and the other, which is spread out
and forked, carry rollers against which a sliding plate bears, the plate
riding in straight or curved templet races to determine the slope of the
grinding as desired. The base plate has uprights, and these support in
suitable bearings the axle or pivots of the emery or other wheel, which
can be rotated by overhead or other motion as desired, the points of the
axle or pivots being received in wooden blocks in sockets of the uprights,
the sockets being capable of fixation with any degree of touch by set
screws,
In the foregoing only one grinding wheel is mentioned; but two or
any number can be mounted in separate headstocks or poppets, and of
the same or of different diameters. If they are of different diameters
their axle frames can be pivoted so that their peripheries can be caused
to bear upon the article or articles under operation.
-
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Gardner in the Great Seal Patent Office
on the 11th March 1875.
TO ALL TO WHOM THESE-PRÉSENTS SHALL COME, I, HENRY
GARDNER, of the Firm of Robertson, Brooman, and Company, of 166,
5 Fleet Street, in the City of London, Patent Agent, send greeting..
=
WHEREAS Her most Excellent Majesty Queen Victoria,: by Her
Letters Patent, bearing date the Eleventh day of September, in the year
of our Lord One thousand eight hundred and seventy-four, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and
O successors, give and grant unto me, the said Henry Gardner, Her
special licence that I, the said Henry Gardner, my executors, admini-
strators, and assigns, or such others as I, the said Henry Gardner,
my executors administrators; and assigns, should 'at any time agree
with, and no others, from time to time and at all times thereafter
tw

page_text: during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN APPARATUS TO FACILITATE THE GRINDING AND SURFACING OF
METALLIC AND OTHER BODIES," Communicated to me from abroad by Louis &
Bollmann, a Citizen of the United States of America, but residing at
Vienna, in the Empire of Austria, upon the condition (amongst
others) that I, the said Henry Gardner, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same
to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
was
NOW KNOW YE, that I, the said Henry Gardner, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:-
:
According to this Invention a base plate supports an adjustable
bracket on its front face, and this bracket holds a table, a slide rest, and
other appliances in or by which the article to be ground or surfaced is
held, the slide rest with the appliances being capable of movement to
the front and rear and also sideways to bring the article under the action
of a rotating disc or wheel, by which the grinding, reducing, surfacing,
polishing, or other manipulation can be effected. The bracket carries a
swing lever and a disc, the latter being pressed upon by a spring and
employed in conjunction with a spring or a weight at the back of the
apparatus, by which an equilibrium or balance of the table and parts
connected with it can be effected. The bracket also carries a swivel
arm, one end of which can be regulated by a screw pin, and the other,
which is spread out and forked, carry rollers, against which a sliding
plate bears, the plate riding in straight or curved templet races to
determine the shape of the grinding as desired. The base plate has
uprights, and these support in suitable bearings the axle or pivots of the
emery or other wheel, which can be rotated by overhead or other motion
as desired, the points of the axle or pivots being reserved in wooden
blocks in sockets of the uprights, the sockets being capable of fixation
with any degree of touch by set screws.

page_text: In the foregoing only one grinding wheel is mentioned, but two or any
number can be mounted in separate headstocks or poppets, and of the
same or of different diameters. If they are of different diameters their
axle frames can be pivotted so that their peripheries can be caused to
bear upon the article or articles under operation.

page_text: backwards and forwards under the emery wheel. The connecting rod J
can be made longer or shorter, according as the work requires it, by
being more or less through a hole in the link bolt K of lever L, wherein
it is fastened by a set screw k.
The table may also be moved backwards and forwards by other means
instead of a lever without affecting the nature of the Invention, for
example, a hand wheel connecting with a toothed wheel gearing into a
rack connected to the table may be as well used, especially when a long
motion should be required. The lever L on the aforesaid wheel or its
equivalent may also be worked in a suitable manner by machinery
instead of by hand.
The lever L is furnished on its fulcrum with a segmental disc L',
against which presses a spring M in such a manner as to act as a brake
to the lever. A set screw m serves to strain the spring more or less, and
thus regulates the amount of friction against the disc L'. On one or
both sides of the sliding table H are guide bars R fastened, which slide
against rollers fastened in the lever Q, which also turns on the shaft F
and serves to regulate the exact position of the table and the work lying
on it in relation to the surface of the emery wheel. When this lever
(see Figures 6, 7, and 8,) is turned on its fulcrum, the rollers q will be
raised or lowered and the table be brought to the exact position required
by the thickness of the work to be finished. The friction of the brake
spring M against the disc L' tends to turn the slide rest on the shaft F
when the lever L is turned on its fulcrum in the direction of the arrow 1,
in the Figure 1, thereby pressing the surface of the work to be ground
against the emery wheel until the guiding bars R rest against the
rollers q, after which no further grinding can take place. The surface
of the work must therefore receive exactly the form of the guide bars R.
There might be straight or curved guide bars used, according as the
work requires.
When the lever L is moved, corresponding with arrow 1, the table will
be moved in an opposite direction to the motion of the emery wheel,
shown by arrow 2. The opposite motion of the lever causes a reverse
movement of the table; the slide rest will then tend to turn on shaft F,
so as to bring the work downwards and away from the emery wheel
while being moved back in the same direction as the wheel turns. The
lever L has therefore to perform two functions, namely, to move the
work under the emery wheel backwards and forwards, and further to

page_text: press the same upwards as it moves in an opposite direction to the
motion of the said emery wheel, and to bring the work downwards so as
not to touch the wheel as it is carried backwards. On the lower part of
the lever Q is acting a set screw S turning in E, which serves to raise or
lower the rollers q, according to the thickness of the work on the table.
If it is required to raise or lower the table more than can be done by
screw S, then the table H may be raised or lowered by first loosening
the screw e by which it is fastened to the frame.
I may here remark that the guide bars R on the table may be avoided
by connecting the sliders G direct with lever Q by means of a pin or
screw, or also by having the slide rest act against a set screw connected
to the back part of frame A in such a manner that the upward motion
of G will be limited according to the thickness of the work. In this
last case also the lever Q will be unnecessary, but only straight surfaces.
can then be ground. On the under side of the slide rests G is fastened
a spring T, the end of which presses against the lever Q in such a
manner that the table and slide rest is pressed upwards with a pressure
corresponding to the tension of the spring, which can be regulated by
the set screw U. The object of this spring is to balance the weight of
the slide rest, table, and work, so that the brake on lever L may act
fully in pressing the work against the emery wheel. The pressure of
the spring T and the brake on the lever L act both together to produce
the exact required pressure against the emery wheel.
. It is obvious that in place of the spring T a weight may be applied to
counteract the weight of the slide rest. Such a weight might be con-
nected by u to pull, by means of a cord, the slide rest upwards, or also
by e direct to force the latter downwards.
In order that such work as is wider than the emery wheel may be
ground, and that the circumference of the latter may work itself even
and true, it is necessary that the slide rest with the work can be moved
in the direction of the length of the shaft F. This is done by means of
the lever O, which turns on a bolt fastened in the table carrier E, and
which through a connecting rod P or its equivalent is connected with G,
as is clearly shown in Figure 1.
I may here remark that the lever O may be connected with the slide
rest in other manners, and also that a toothed wheel and rack or a screw
may be employed to effect the sideward motion of the slide rest.

page_text: In all former machines working with emery wheels the application of
a slide rest for carrying the work has been connected with so many
difficulties that they have come till now but little into use. The main
difficulty has been that the slide rest was made rigid instead of yielding.
The pressure of the work against the emery wheel could therefore not
be exactly regulated, in consequence of which the surface to be ground
would be heated even to red heat. This causes the destruction of the
grinding surface of the wheel, so that it will get glazed and cannot cut
the work, and also makes the ground surface very hard. A fixed un-
yielding slide rest is also very dangerous to use, because when a large
cut is to be taken off the wheel, which must run at a great speed, will
often get jammed, and thereby burst into pieces.
In this Invention these difficulties are entirely overcome. The pressure
against the wheel can be exactly regulated, and the surface of the work
is not cut at once but successively, by being repeatedly passed backwards
and forwards under the wheel until it is finished to the exact thickness
and to the shape of the guide bars. In consequence of the light pressure
against the wheel, very small bearings can be employed for the spindle
without danger of breaking them; only conical points therefor are
used, as herein described, which reduces the friction and wear, and sim-
plifies the machine to a great extent.
In larger machines where heavy cuts must be taken from the work,
two emery wheels are employed, one for rough and the other for smooth
cutting. These wheels are each fastened on a separate spindle, and each
spindle has its bearing in a separate frame, both of which swing on a
horizontal shaft, out in the same manner as does the slide rest on the
shaft F before described. The shaft is placed at a height about equal to
the spindles of the emery wheels. These wheels are fastened on the
ends of their spindles, whose axes are in one line, so that the wheels run
close side by side as if both were placed on one spindle.
Each of the frames can be separately turned on the shaft by means
of set screws, in order to lower or raise each of the wheel spindles
separately. The object of this arrangement is to be able to set the
height of each wheel so that the lower grinding surfaces of both should
always be nearly level with each other, whatever the difference of their
diameters might be, for the first rough cutting wheel must remove the
most metal, and will therefore generally wear much faster than the

page_text: Sixthly. Giving to the slide rest a motion to the right or left on a
shaft by means of a lever or its equivalent.
Seventhly. Connecting guide bars to a sliding table, and its action.
against rollers for giving to the work the exact shape required.
Eighthly. The combination of a yielding slide rest with two emery
wheels on two independent spindles bearing in two swinging frames,
the two wheels being placed side by side, and one of them used for
rough grinding while the other does the smooth finishing of the work,
each of them being capable of being raised or lowered to the work, as
the difference of wear requires, by means of set screws, the two frames
in which the wheel spindles bear swinging on a shaft, all as set
forth.
In witness whereof, I, the said Henry Gardner, have hereunto set
my hand and seal, this Eleventh day of March, One thousand
eight hundred and seventy-five.