Improvements in Machines for Grinding Plane Surfaces.
Year: 1889

page_text: Date of Application, 9th Dec., 1889-Accepted, 25th Jan., 1890
COMPLETE SPECIFICATION.
Improvements in Machines for Grinding Plane Surfaces.
We, ELWIN RUFUS HYDE, Manufacturer, of 29 Osgood Street, Springfield,
Massachusetts, and RICHARD CHEW HORNER, Mechanical Engineer, of 66 Bancroft.
Street, Springfield, Massachusetts, United States of America, do hereby declare the
nature of our invention for "IMPROVEMENTS IN MACHINES FOR GRINDING PLANE
SURFACES," and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
Our invention relates to that class of abrading machines in which are comprised
one or more revolving abrading wheels or tools, and a work-support for exposing the
surface of the article to be operated upon to the action of said wheels or tools,
for the "purpose of reducing said surface to a uniform plane; and it has especial
rference to machines of this class in which the work-support is itself revolved in a
plane at a right angle to the plane of revolution of the abrading wheels or tools.
The object of our invention is to increase the effective abrading capacity of such
machines and also to combine therewith means whereby the adjustments of the
several parts of the machine itself, and the introduction of work thereto and its
removal therefrom will be greatly facilitated and expedited.
To this end our invention consists in a machine of this nature in which the
abrading medium has both a revolving and a reciprocatory movement relatively to
the work-support, and in which the latter also revolves about an axis which is perpen-
licular with that of said abrading medium.
It consists further in such a machine having combined with the revolving and
laterally-reciprocating abrading medium a plurality of revoluble work-supports each
of which can be moved to a position in which the surface of the work supporte I thereon
will be exposed to the action of the abrading medium.
Our invention furthermore comprises certain details of construction hereinafter
fully described and particularly pointed out in the claims.
Referring to the drawings in which like parts are designated by like letters in the
several figures.
Figure 1 is a side elevation of the machine looking toward the left in Figure 2.
Figure 2 is a front elevation thereof.
Figure 3 is a vertical longitudinal section of the front portion of the frame of the
machine and of the work-supporting devices.
Figure 4 is a plan view of the mechanism for reciprocating the cross-head which
carries the abrading medium.
Figure 5 is a similar view of the mechanism for revolving the work-holding
tible, the outlines of the tables and their supporting bed being indicated by broken
lines.
Figures 66ª, 6, 6º, and 6ª, are detail perspective views of the devices by which the
abrading medium is adjustably supported.
Figure 7 is a view of the perspective of one of the revolving tables which support
the work.
Figure 8 is a cross-section thereof taken upon line 8-8 of Figure 7.
Figure 9 is a view in perspective of one of the jaws of the work-holding clutches.
Figure 10 is a vertical section thereof, taken upon line 10-10 of Figure 9.
The letter A designates the frame of the machine, which frame terminates at the
front end in a vertical cylindrical hub A' and at its rear end in an upright and
slightly overhanging arm A2, which arm and hub support respectively the abrading
and work-holding mechanisms. Frame A is preferably made hollow in form to
lessen its weight and also to enable that portion thereof lying in front of arm A² to bo
CD1177

page_text: utilized as a reservoir for water when the abrading medium is of the "wet grinding
class, which reservoir is designated by the letter A³ in Figure 3.
As herein shown the abrading medium is composed of two emery wheels B B¹
of a corresponding diameter, which have a common revolving and laterally recipro-
cating movement and a common vertical adjustment, and in addition to such common
movements each of said wheels is preferably provided with means whereby it can be
independently adjusted both vertically and laterally. The means shown for securing
these various movements of the abrading medium will be first described.
The upright arm A2 of the frame which preferably curves slightly toward the front
end of the frame, terminates in a vertical face of considerable area as shown, and
projecting from said face are two vertical ribs a the outer edge of each of which is
undercut as shown in Figure 4. The letter C designates a bead-block in the rear side
of which is a vertical groove c having undercut edges to receive the outer edges of
the ribs a on arm A2 and thus retain the head-block upon the arm in such manner
as to permit free vertical movement of the former. By making two ribs a upon
the arin instead of a single rib of the full width of groove c, the wearing surface of
said parts is materially reduced without weakening the connection between them.
Head-block is provided at each end with arms c¹² projecting horizontally
therefrom, the front faces of which arms are flush with the front face of the block,
and the rear faces of which are preferably provided with strengthening ribs c³ as shown.
Projecting from the front face of the head-block and its arms is a rib c³,
extending at a right-angle to the groove c in the rear face of the block, the edges
of which rib are undercut to receive the undercut edges of a groove d in the rear
side of a cross-head D, whereby said cross-head is retained and permitted to have free
lengthwise movement upon said block. Said cross-head D, shown in detail in
Figure 6, is preferably slotted as shown at d¹ for the greater portion of its length,
and is provided at its front side with a longitudinal rib d² having undercut edges
to receive the edges of a groove e in the rear faces of two corresponding plates E E¹
and thereby adjustably retain said plates upon the cross-head. Right and left hand
screws, see Figure 6b, are mounted in a block d seated in the end of
cross-head D and retained therein by means of screws d as shown, or in any other
convenient manner, said screws being provided with collars upon each side of said
block whereby they are adapted to have a free revolving movement therein without
endwise progression. Each of the plates E E' is provided upon its rear side with
a projecting threaded hub e which hubs, when the parts are assembled, project
within the slot in the cross-head and receive respectively the threaded portions of
screws dad, whereby by turning said screws by means of a wrench or permanent
handle, said plates E E' can be adjusted independently toward and away from each
other upon said cross-head. Upon their front sides each of the plates E E' is
provided with a vertical rib e² having undercut edges to receive the edges of vertical
grooves in the rear sides of two wheel-heads F F', one of which heads is shown
detached in Figure 6. Adjusting screws f¹ mounted in upwardly projecting
brackets fon said wheel-heads in such manner as to revolve without end wise
progression, are tapped into the plates E E' at their lower ends, and are preferably
provided with the usual handles f³ at their upper ends as shown. By means of said
screws either of the wheel-heads can be independently adjusted in a vertical
direction upon the plates E E³. Projecting from the front side of each of the
wheel-heads F F¹ are two arms f* containing bearings for one of the shafts B² which
carry the abrading wheels B B₁ respectively. One of said abrading wheels
is suitably secured to the inner end of each of said shafts B2, and upon each
of said shafts between its bearings f is secured a band pulley 6 by which
revolving movement is transmitted to said shafts and abrading wheels from a
suitably arranged counter-shaft. It will be observed that by the means just described
provision is made for independently adjusting the abrading wheels both laterally and
vertically, the former adjustment being for the purpose of guaging the distance
between said wheels according to the width or diameter of the work to be operated
upon, and the latter adjustment being for the purpose of compensating for unequal

page_text: wear of said wheels by slightly depressing the one which wears away the most quickly,
should it become necessary to do so.
In addition to the two independent adjustments the wheels B B' have a common
laterally reciprocating movement with the cross-bead upon head-block C, and also a
common vertical movement with said head-block upon arm A2 of the frame, as herein-
before stated, and to the means for producing such common movements attention is
next directed.
a
Upon the rear sides of arms c¹ c² of head-block C are secured by screws as shown or
in any suitable manner threaded hubs c which bubs receive respectively right and
left hand threaded, vertical screw shafts C, which shafts are mounted at their lower
and upper ends in bearings ce upon each side of the frame of the machine. At their
upper ends said screw-shafts carry bevel-gears c and mounted in bearings upon the
top arm A³ is a cross-shaft C² carrying at each end bevel-gears c which mesh with
said gears c and thereby transmit the motion of one of said screw-shafts to the other
in a well known manner. The screw-shaft on the right of the frame as seen in
Figure 2, is continued nearly to the bottom of the frame, and carries at its lower end
bevel-gear c³ which meshes with a bevel-gear coupon the rear of a horizontal
shaft mounted in suitable bearings upon the side of the frame. Said shaft c³
extends to or nearly to the front end of the frame, and at its front end is squared to
receive a wrench, as shown, or may be provided with a suitable hand-wheel, to enable
said shaft to be revolved manually. Revolution of shaft C³ will through the arrange-
ment of the gears and a cross-shaft, as just described, impart a similar movement to
both screw-shafts C¹, in opposite directions, and by the movement of the threaded
hubs cupon said screw shafts head-block C, the cross-head, and wheels B B', will be
raised or lowered upon arın A2 as said shaft ( is turned in one or the other direction.
In order to counter-balance said block and the parts carried thereby and thus render
the vertical adjustment thereof as just described very easy, we connect one end or
a rope or chain c" thereto by means of an eye c¹² secured to the head-block midway
between the ends of the latter, and conduct said rope or chain over two pulleys cls
mounted in brackets secured in arm A2 to the interior of said arm where suitable
weights are suspended thereon, as shown by broken lines in Figure 1. The object of
the common vertical adjustment of wheels B B¹, thus effected is for the purpose of
lowering said wheels upon and raising them from the work, and also to regulate their
grinding action upon the surface of the work, and by the means just described a very
delicate vertical adjustment of said wheels can be made with perfect ease. The lateral
reciprocating movement of wheels B B' is produced as follows:
A horizontally extending bracket G is rigidly secured to arm A² of the frame
near its upper end, which bracket is provided with bearings g for a horizontal
worm-shaft G carrying worm gl and cone-pulley 9", see Figure 4. Said bracket
is also provided with bearings 93 for a vertical shaft G2, the upper end of which
shaft passes loosely through said bearings and through a worm-gear 9 which is
mounted between said bearings and which meshes with worm gl. A spline and
key connection between shaft G2 and worm-gear g, as shown, compels said shaft
and gear to revolve in unison while permitting the former to move vertically
within the latter. Said shaft G2 is mounted at its lower end in a bearing h of a
bracket, H secured to the rear side of arm c² of head-block C by screws passing
through said bracket into a seating formed upon said arm, as shown by broken
lines in Figure 4, or in any other convenient manner. Collars secured upon said
shaft above and below said bracket H compel the former to follow the vertical
movements of the latter as head-block c is moved up or down, and to the lower
end of said shaft is secured a gear-wheel 9' which meshes with a similar gear-
wheel secured to the lower end of a short vertical shaft G³ mounted in a
bearing in said bracket H. At its upper end said shaft G³ carries a crank-
disk ', having a crank-pin 8 adjustable toward and away from the center of said
disk by a screw g in the usual manner. A link g connects said crank-pin with
cross-bead D as shown in Figures 2 and 4. Motion being communicated_to worm-

page_text: shaft G¹ from a suitably arranged countershaft through a belt and cone-pulley 9²,
said shaft will through worm g³, gear 94, shaft G² and gear-wheels 96 96, impart a
uniform revolving movement to shaft G³ and crank-disk g', and the latter
through link go will impart a horizontal reciprocating movement to the cross-head
and wheels B B', the amount of which reciprocating movement can be accurately
gauged by the adjustment of crank-pin 9. The abrading wheels B B¹ receive
their revolving movements by means of belts connecting their pulleys & with a
countershaft, which belts will preferably be led over intermediate idler-pulleys
which are free to move lengthwise of their shafts, to enable the belts to follow the
reciprocating movements of said wheels. By means of the compound revolving
and reciprocating movement of the abrading wheels thus secured their capacity for
quickly reducing the surface of the work is greatly increased, but this desirable
result is still further increased by the revolving movement which is imparted to
the work itself in a plane at a right angle to the plane of revolution of said
wheels, and to the means devised by us for supporting and thus revolving the
work attention is now directed.
As hereinbefore stated, one of the objects of our invention is to combine with
the means for holding and operating the abrading medium as shown and described,
a plurality of revoluble work-holding mechanisms, each of which can be moved to
a position to present the surface of the work held thereon to the action of the
abrading medium. By thus providing two or more of such work-holding
mechanisms we are enabled to greatly expedite the operation of the machine inas-
much as new work can be secured upon and finished work removed from those
that are idle at the same time that the abrading medium is operating upon the
work held by the one which is in operation. For the purpose of illustrating this
feature of the invention we have shown two of these work-holding mechanisms
which are constructed as follows:
The
The letters II designate two circular tables carried at the upper ends of short
shafts, i, said tables having the usual intersecting slots, T-shaped in cross-section
within their upper surface, and having concentric bearing surfaces on their lower
surface, as shown in Figures 7 and 8. The shafts i of said tables are mounted
in vertical bearings within and upon opposite sides of the center of a bed K,
which bed is mounted upon hub A¹ of the frame by means of a tubular stud k
projecting within said hub, as shown in Figure 3, whereby said stud serves as a
pivot about which as a center the bed is free to revolve horizontally. As shown,
the bed is substantially oval in outline and is provided upon its upper surface
with concentric bearing surfaces corresponding to those upon tables I. and is
preferably provided around its edge with an upwardly projecting flange k².
upper surface of the bed, with the exception of the horizontal bearing surfaces k
preferably slopes gradually and downwardly from its edge toward its center where
it is provided with an opening extending through stud k, as shown in Figure 3.
whereby the water used with a "wet grinding" abrading medium which falls
upon said bed, is caused to seek said central opening in the latter and descends
therethrough into the reservoir in frame A. The tables I are provided with
downwardly extending annular flanges which overlap the edges of the outer
concentric bearing surfaces of the bed as shown, and prevent the water, particles
of emery, etc. from working between the respective bearing surfaces of the tables
and bed, thereby avoiding a common cause of injury to said surfaces.
Upon the upper surfaces of tables I are clutches for engaging and holding the work.
Said clutches preferably consist of two or more jaws I', see Figures 9 and 10,
composed of a lower member which is secured to the table by bolts with T-shaped
heads located within the slots in the table, and an upper member movably secured
upon said lower member and adjusted thereon by a screw which is mounted in a
bearing on the lower member and enters a nut secured to the upper member.
have shown the working faces of the jaws of said clutches as being formed upon the
are of a circle and concentric with the centers of the tables, thereby adapting them for
We

page_text: use in connection with circular work, but it will be understood that said working
faces will be formed to correspond with the character of work upon which the machine
is to be used.
Upon the lower ends of shafts i of the tables, and beneath bed K, are secured
corresponding worm-gears, collars being located upon said shafts between said
gears and the lower surface of the bed to ensure steadiness of movement to the shafts.
The letter L designates a worm-shaft which is mounted at one end in a bearing?
pivotally secured to a bracket L' projecting from frame A, in such manner that said
bearing is free to turn horizontally upon its pivot. Near its opposite end said shaft L
is supported by a bearing secured to a plate 12, which plate rests upon a seating
formed upon frame A to which it is secured by bolts 13 passing through slots in
the plate, whereby said plate is permitted to have a limited sliding movement toward
and away from the hub A' of the frame. Shaft L at its free end carries a worm 1
which is adapted to mesh with one of the gears 4 of tables I when plate l² occupies its
forward position, but which is moved to a position to clear said gear when said
plate is moved to its rearmost position. Near its opposite end said shaft is provided
with a band-pulley by which motion is transmitted to said shaft from a counter-
shaft through a belt. It follows from the construction just described that when
either of the gears is in mesh with the revolving worm its table I and the
work held thereon will be given a uniform revolving movement in a horizontal
plane, and it follows, furthermore, that by moving said worm to a position to clear
said gear, the bed K can be revolved about its pivot to bring, the opposite gear and
table beneath wheels B B¹. It is essential that means be provided for locking the bed
to prevent movement thereof while the abrading medium is operating upon the work
carried by either of the tables I, and we have combined means for the purpose with
the means for a shifting plate 12 and worm 15 in such manner that both functions are
performed by a single lever. Said lever designated by the letter M is pivoted at m to
the side of the frame A, its short arm extending upwardly to the plane of bed K and
its long arm extending to the front end of the frame where it terminates in a suitable
handle as shown. To the end of the short arm of said lever is pivotally connected the
rear end of a bolt m¹ sliding within a sleeve m² secured to the side of arm A². Bed K
is provided at each end with a socket k³ to receive the front end of said bolt, so located
upon said bed that when either of the tables I is directly beneath wheels B B¹ one
of the sockets will be opposite the ends of said bolt. By moving lever M in
one direction, bolt m¹ will be thrust forward to cause it to enter one of the sockets on
the bed, and by moving said lever in the opposite direction, said bolt will be withdrawn
from its engagement with the bed. A lever N pivoted at one end to frame A, as
shown in Figure 5, is connected at its opposite end by means of a link n to the short
arm of lever M, and between its ends, by means of a link n' to plate 12. It follows,
therefore, that the same movement of lever M which withdraws bolt m¹ from
engagement with the bed will withdraw worm 15 from mesh with either of the gears it,
and, conversely, that the same movement of said lever which restores said worm to
mesh with one of said gears will project said bolt into one of the sockets of the bed
and thus rigidly hold said bed from movement. A standard m³ secured to the frame
adjacent to the end of the long arm of lever M is provided in its side next to said lever
with a notch, as, shown in Figure 2, to receive the latter, and retain it in the position
shown by broken lines in Figure 1, whenever it may be desired to do so.
As the abrading wheels bear with a heavy pressure upon the work, and as the latter
is supported upon bed K at one side of the central support of said bed, we provide the
bed at each end with a downwardly projecting bearing in which is journalled an
anti-friction roll 4, and provide frame A with a shoulder a¹ upon which one of said
rolls bears, as shown in Figures 1 and 3 in each operative position of the bed. By
this means the downward pressure of the bed during the operation of the abrading
wheels upon the work is distributed between shoulder a¹ and hub A', and undue strain
upon the bed is avoided.
When the abrading wheels employed are of the class known as
66
wet grinding"

page_text: wheels, we design to utilize a small centrifugal or other pump to raise water from the
reservoir in frame A and carry it through suitably arranged pipes to the surface of
the wheels whence it passes to the bed and from thence back into the reservoir as
previously described. A constant circulation of the same water is thus effected which
is especially advantageous in locations where it is not convenient to connect the
machine with water supply and escape pipes. We have not shown said pump and
water conducting pipes for the reason that their use is common, to all of our wet-
grinding machines; and because they form no part of our present invention. For
the purpose of affording access to the reservoir the frame is provided with an opening a²
which opening is normally closed by a cover as shown in Figure 3. Access to arın A²
of the frame is also afforded by a door a³ as shown in Figure 2, in case it should be
desirable to enter said arm for any purpose. The operation of the machine thus
constructed is as follows:
Presuming band-pulleys bb, 92 and 16 to be connected by belt with the same or
different counter-shafts whereby revolving movement is transmitted to wheels B B¹
and worm-shafts G₁ and L, wheels B B₁ are adjusted laterally by means of screws d³ (*
to locate them at the proper distance apart with respect to the width or diameter of
the work to be operated upon, the work itself is firmly clamped between the clutch-
jaws of one of the tables I, bed K is manually revolved to move said table and work
beneath the abrading wheels, lever mis moved to project bolt m¹ into the adjacent
socket of said bed and also to move worm into mesh with the gear it of said table,
and the machine is set in operation. The revolving and laterally reciprocating abrading
wheels are now lowered upon the work by turning shaft C3, and are regulated as to
their abrading action upon the surface of the work by means of said shaft as
herein before described. The work itself being revolved in a plane at a right angle
to the plane of revolution of the abrading wheels, the latter very rapidly reduce the
surface of the former, and the lateral reciprocating movement of the wheels, causes
the surface operated upon to be a true plane. When two abrading wheels are employed,
as shown, they will preferably be of different degrees of coarseness, so that one of
them will perform the function of a finishing wheel, and should one of said wheels
wear away more rapidly than the other it can be depressed to compensate for such
wear by means of its screw f¹. Either of the wheels B B' moreover, can be moved
by one of the screws d³ d to a position where it will be entirely clear of the work,
whenever it is desired to use but one of said wheels, thus enabling the machine to
operate as a single wheel machine. While the abrading wheels are thus operating
upon the work carried by one of the tables I, new work can be clamped upon the idle
table ready to be moved under the wheels as soon as they have completed their first
operation, whereby a great saving in time in feeding work to and removing it from
the machine is effected.
Bed K is balanced upon hub A of the frame in such manner that it can be revolved
upon said bub with but slight exertion, but if desired any suitable anti-friction devices
can be employed to increase its freedom of movement.
Having completed the operation upon the first piece of work, wheels B B¹, are
elevated slightly by turning shaft C³, lever M is moved from the position shown by
full to that shown by broken lines in Figure 1, bed K is revolved to move the second
table beneath the wheels, said lever M is restored to its former position and
wheels B B are lowered upon the new work, and the operation proceeds as before.
The operation would be the same were the bed provided with more than two tables I,
each being moved under the abrading wheels in regular sequence.
The work for which the machine herein shown and described is especially designed
is the grinding of the annular bearing surfaces of valve-bodies and other similar
circular work, in which the wheels B B operate at diametrically opposite points upon
the surface of said work, but it is adapted to operate equally well upon flat surfac s
generally.
While we have shown and described the abrading medium as consisting of emery
"wheels, it will be understood that we do not thereby wish to limit ourselves to

page_text: the use of such material as it is obvious that the particular abraiding material
employed is not essentially related to the construction and operation of the machine-
itself.
It is obvious furthermore, that various modifications of the details of the construc-
tion shown and described can be made without departing from the spirit of our
invention.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The machine for grinding plane surfaces herein described comprising in com-
bination a revolving and laterally reciprocating abrading medium and a revolving
work-support, the plane of revolution of the latter being at a right-angle to that of
the former, substantially as set forth.
2. The machine for grinding plane surfaces herein described comprising in
combination a revolving and laterally reciprocating abrading medium, and a plurality
of revoluble work-supports mounted upon a common revoluble bed whereby each of
said work-supports can be moved to a position to present the surface of the work
carried thereby to said abrading medium, substantially in the manner and for the
purpose described..
:
3. The machine for grinding plane surfaces herein described comprising in'
combination a revolving and laterally reciprocating medium, a revoluble bed having,
its plane of revolution at a right angle to that of said abrading medium, a
plurality of revoluble work-supports mounted upon said bed, each of which work-
supports is provided with a worm-gear, and a worm shaft mounted in movable
bearings, whereby the worm carried thereby can be moved into and out of engage-
ment with the gears upon said work-supports, arranged and operating substantially
as described.
4. In a machine for grinding plane surfaces the combination of the following
instrumentalities, viz.: a substantially horizontal frame terminating at one end in an
upright arm, a head-block secured to and vertically adjustable upon said arm, a
horizontally movable cross-head mounted upon said head-blocks, one or more wheel-
heads adjustably secured to said cross-head, each of said wheel-heads having
journalled thereon, a shaft carrying an abrading wheel a crank-shaft having link
connection with said cross-head whereby revolution of the former will produce a
reciprocating movement of the latter, a worm-shaft carrying a band-pulley, inter-
mediate gear connections between the worm upon said shaft and said crank-shaft, and
a revolving work-support mounted upon said frame beneath the plane of said abrading
wheels arranged and operating substantially as set forth.
5. In a machine for grinding plane surfaces, a substantially horizontal frame
terminating at one end in an upright arm, a vertically adjustable bead-block mounted
upon said arm, a longitudinally reciprocating cross-head carried by said head-block,
two vertically and horizontally adjustable wheel-heads mounted upon said cross-head,
a shaft carrying an abrading wheel and a band-pulley, journalled in each of said
wheel-heads, a bed mounted upon a vertical axis upon said frame, and a plurality of
revolving work-supports mounted upon said bed, arranged and operating substantially
as set forth.
6. In a machine for grinding plane surfaces, frame A having upright arm A² at
one end thereof, head-block C adjustably mounted upon said arm, cross-head D
mounted to slide transversely upon said head-block, said cross-head being slotted as
shown at d¹ and having adjusting screws 3d mounted to revolve without end wise
progression in one end thereof and extending into said slot, plates E E¹ movably.
mounted upon said cross-head each of said plates having a nut e¹ extending into the
slot in the cross-head and receiving one of said screws d³ d, wheel-heads F F
vertically movable upon said plates E E' respectively, adjusting screws f' mounted
apon said wheel-heads and tapped at one end in said plates, and shafts B² each
carrying a band-pulley and an abrading wheel journalled in said wheel-heads,

page_text: arranged and operating substantially as described, whereby provision is made for
independently adjusting said wheel-heads both vertically and horizontally upon said
cross-head.
7. In a machine for grinding plane surfaces, frame A having arm A2 at one end
thereof, head-block (supporting the revolving and laterally reciprocating abrading
medium and having a vertically sliding connection with said arm A, threaded hubs c
secured to said head-block, vertical screw-shafts C'C' having right and left hand threads
engaging the threads in said hubs, each of said shafts having at its upper end a bevel-
gear c and one of said shafts having at its lower end a bevel-gear c³, cross-shaft.c²
having at each end bevel gears c³ meshing with the gears e² of said screw-shafts, and
horizontal shaft 3 having at one end bevel gears el meshing with the gear c at the
lower end of one of said screw-shafts and having its opposite end provided with suit-
able means whereby it can be revolved manually, combined and operating substantially
as and for the purpose described.
8. In a machine for grinding plane surfaces, frame A having at one end upright
arm A supporting the abrading medium and having at its opposite and cylindrical
hub A¹, bed K resting upon said hub and having a central stud k projecting within
the latter, a plurality of work-supporting tables I mounted upon said bed by means
of short vertical shafts passing through the latter and carrying worm-gears i at
their lower ends, a worm-shaft L mounted at one end in a pivoted bearing and near its
opposite end in a bearing secured to a sliding plate 2, said shaft carrying band-
pulley and worm, and means substantially as described for moving said plate /*
toward and away from hub A', combined and operating substantially as described,
whereby said worm can be moved into and out of engagement with either of the
worm-gears connected with said work-supporting tables.
9. In a machine for grinding plane surfaces, the combination with frame A having
revolubly mounted thereon bed K carrying tables I, said tables having vertical
shafts and worm-gears it at the lower ends of said shafts, of a locking device on said
frame to engage said bed and prevent movement thereof, sliding plate 12 mounted
upon said frame and supporting one end of worm-shaft L carrying worm 1, a lever
as M fulcrumed upon said frame, and intermediate connections substantially as
described between said lever, sliding plate 12, and the locking device, whereby move-
ment of said lever will impart movement to said plate and locking device simultan-
eously, substantially as and for the purpose set forth.
10. In a machine for grinding plane surfaces, the combination with frame A,
bed K having a horizontal revolving movement upon said frame, and tables 1 having
a horizontal movement upon said bed, of worm-gears operatively connected with
said tables, worm-shaft L mounted at one end in a pivoted bearing and near its
opposite end upon sliding plate 12, elbow lever M pivoted upon the side of frame A,
locking-bolt connected at its rear end to the short arm of said lever, sockets k³
upon bed K to receive the front end of said bolt, lever N pivoted at one end to
frame A, link n connecting the opposite end of said lever with the short arm of
lever M, and link n¹ connecting said lever N between its ends with sliding plate,
arranged and operating substantially as and for the purpose set forth.
11. In a machine for grinding plane surfaces, frame A having at one end upright
arm A2 and shoulder a' and at its opposite end hub A', of bed K centrally pivoted
upon said hub, said bed having the work-supporting tables I mounted thereon between
its center and its edge, and having at its outer edge and opposite each of said tables
downwardly extending brackets in which are journalled anti-friction rolls k³ one
of which rolls rests upon said shoulder a¹ of the frame whenever either of said tables I
occupies its operative position, combined and operating substantially as and for the
purpose set forth.
12. In a machine for grinding plane surfaces, hollow frame A having at one end
upright arm A2 and at its opposite end cylindrical hub A', communicating with
reservoir A³ in said frame, in combination with bed K having a central tubular stud k
projecting within said hub A¹, said bed having an upwardly extending flange k
extending around its outer edge, a central opening communicating with the bore of

page_text: stud k, and horizontal annular bearing surfaces k, and having its upper surface with
the exception of said bearing surfaces inclined downwardly from the edge of the
central opening thereof, and tables I, I supported upon the bearing surfaces of said
bed, substantially as and for the purpose described.
13. The combination with bed K having the annular bearing surfaces k¹ of
tables I, I having corresponding bearing surfaces upon their lower side, and having
the annular flange adapted to overlap the outer bearing surfaces of said bed,
substantially as and for the purpose described.
3000
Dated uns a way of
1000
ELWIN RUFUS HYDE.
RICHARD CHEW HORNER.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicants.