IMPROVEMENTS IN MACHINES FOR PLANING OR DRESSING THE SURFACES OF LITHOGRAPHIC AND SIMILAR STONES
Year: 1884

page_text: I, WILLIAM ROBERT LAKE, of the firm of Haseltine Lake & Co. Patent Agents,
Southampton Buildings London in the County of Middlesex do hereby declare the
nature of said Invention for "IMPROVEMENTS IN MACHINES FOR PLANING OR
DRESSING THE SURFACES OF LITHOGRAPHIC AND SIMILAR STONES" 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 machines for planing or dressing the surfaces of
lithographic and other soft stones.
The method most commonly employed for dressing lithographic stones after use,
in order to remove the designs drawn thereon in ink, and give them a smooth and
level surface ready for new work, consists in rubbing another stone the
over
surface with fine sand and water between the two. This operation is, however,
slow and tedious, and requires great skill to render the surface perfectly level and
uniform as is necessary, especially when the stones are to be used in large cylinder
presses. Machines have been also employed for this purpose, in which a revolving
metallic disc was used for grinding down and polishing the surface of the stone;
and a knife or scraper has also been employed in connection with a reciprocating
carriage for supporting the stone, the scraper acting upon its surface during
its movement in one direction only. None of these machines have however
accomplished the desired end in a sufficiently rapid and perfect manner to warrant
their general use.
The object of this Invention is to facilitate the operation of dressing the stone
and to enable the work to be performed much more rapidly and at the same time.
obtain a uniform surface over the entire stone, and also to obtain stones of
exactly the same thickness.
The said Invention comprises a stone-planing machine having a pair of cutters
or scraping knives adapted to be rocked or vibrated to bring them alternately,
into contact with the stone as it is traversed in opposite directions. by means
reciprocating.carriage, the, shifting of the cutters taking place just previous to the
of a
;
1

page_text: ATTIVAL OF the stone at the end of its traverse in either directION;
various details of construction as hereinafter set forth.
In the accompanying Drawings
It also comp
Figure 1 is an elevation of one side of the improved stone-planing machine.
Figure 2 is a plan of the same.
Figure 3 is an elevation of the side of the same opposite to that represented in
Figure 1.
Figure 4 is a longitudinal vertical section through the centre of the machine.
Figure 5 is an end elevation.
Figures 6 and 7 are sectional views of details.
Figure 8 is a transverse vertical section through the machine on the line xx
Figure 3.
Figure 9 is a perspective view of the cutter stock and cutters.
Figure 10 is a section on the line y y Figure 7.
Figure 11 is a transverse vertical section, drawn to an enlarged scale, through
the cutter stock and cutters.
A indicates the bed or frame-work of the machine which is provided with
guideways bb on which slides a carriage B upon which is secured, by any suitable
device, the lithographic or other soft stone C to be planed. This carriage has
secured to its underside a heavy lug or projection c through a threaded aperture in
which passes a long horizontal screw-shaft D supported in suitable bearings de
secured to the bed A between the guideways b b. To one end of the shaft D is
secured a large gear-wheel E which is driven by a smaller gear-wheel or pinion G
on a short shaft fupon which are mounted the driving or fast pulleys g h between
which are arranged three pulleys il running loosely upon the said shaft f.
mn indicate the belt shippers by means of which the belts p q are alternately
shifted from the fast to the loose pulleys, and vice-versa to cause the screw-shaft
to be rotated in. opposite directions whereby the carriage is traversed, backwards,
and forwards, from one end of the bed A to the other. The central loose pulley /
onto which each of the belts laps when shifted from its fast pulley, serves to
prevent one belt from being moved onto a fast pulley until the other belt has
nearly, or entirely, cleared the other fast pulley. The belt-shippers m n are
secured to a sliding bar r to which is pivotted a connecting rod s the opposite end
of which is provided with a stud which works in a slot 15 at the upper end of a
lever t secured to one end of a rock shaft H having its bearings in the framework
and extending, transversely through the same from one side to the other. The
shaft H is provided near its opposite end with a lever u which is alternately
vibrated in opposite directions by adjustable projections vw at the opposite ends
of the carriage B; and thus, through the connections described, the belts p q are
shifted and the motion of the screw. shaft D reversed as soon as the carriage has
arrived at the end of its traverse in either direction.
On each side of the framework A is bolted a heavy standard I, and between
these standards is placed a cross head K the ends of which fit within vertical
slots a¹ in the standards. This cross head K which carries the cutters or 'scraping
knives to be hereinafter described is supported at its opposite ends by two vertical
screw-shafts b¹ which pass through the cap-piece L secured to the upper ends of the
standards. These screw-shafts b' are provided at their upper ends with worm gear
wheels which are rotated by worms d¹ on a horizontal shaft M having its
bearings in projections rising from the cap piece L. The shaft M is provided at
one end with a ratchet wheel e¹ which is rotated in the same direction alternately
by the pawls f g pivotted to the levers h¹¹ oscillating freely upon the shaft M,
and arranged upon opposite sides of the ratchet wheel. These levers are connected
by rods with the upper end of a lever N secured to the end of the rock-shaft H,
the vibration of which, at the end of each traverse of the carriage B by the contact
of one of the projections vw with the lever u as previously described, causes the
rotation of the ratchet wheel e¹ and the screw shafts b¹ and the downward feed of
the cross head K and cutters attached thereto. The arrangement of the pawls
-

page_text: upon opposite sides of the ratchet wheel causes one pawl to engage with its teeth
when the lever N is rocked in one direction, and the other to engage with the teeth
when the lever is rocked in the opposite direction whereby a movement of the feed
mechanism of the cutters is produced at the end of each traverse of the carriage.
Within a long slot m¹ in the cross head K is hung, on pivots n¹, the rocking.
cutter stock or holder P, to which are secured by bolts p' the scraping knives or
cutters q¹¹ which act upon the surface of the stone and plane the same as -
required. The cutters are shaped at their lower ends as seen in Figures 3; 4, 7
and 9, and are arranged back to back, so that, when the stock P is inclined to one
side in the slot m¹, the cutting edge 20 of the knife q' will be in a position to act
upon, and scrape, the surface of the stone C while travelling in the direction of the
arrow, the edge of the other knife ¹ being raised out of contact with the stone;
while, when the stock P is thrown over in the opposite direction, the cutting edge
of the knife r¹ will be brought into contact with the stone, ready to scrape or plane
the same while travelling in a direction contrary to the arrow, the knife q¹ being
then raised out of contact with the stone. By this construction it will be seen
that the stone is planed at each traverse of the carriage, thus avoiding much loss of
time and effecting a material saving in the cost of dressing or preparing the surface
of lithographic and other soft stones.
The oscillation of the cutter stock P is effected in the following manner that is
to say, To one end of the stock is secured a toothed segment s' which engages
with a similar segment t¹ secured to one end of a short shaft u' supported in a
bearing wl in one end of the cross head K. The opposite end of the shaft u¹ has
secured to it, a lever a² the lower ond of which is connected by a rod b2 with the
lever N, so that as the latter is rocked, the cutters are shifted. As the movement
of the cutters takes place just previous to the arrival of the stone C at the end of
its traverse in either direction and at the same instant that the cutters are shifted,
the downward feed of the cross head with the cutter stock is produced to cause the
next cutter to be lowered, sufficiently to shave off a fresh portion of the surface of
the stone. The slot 15 at the upper end of the lever t affords the necessary
amount of lost motion to prevent the belts from being shifted until the lever N
has nearly completed its movement in either direction, as is necessary to ensure
the cutters being oscillated from the succeeding cut before the belts are shifted
to cause the stone to travel in the opposite direction.
The cutters are made adjustable vertically in the stock P by means of screws c²,
any suitable number of which may be employed at different portions of the length
of the cutters. By means of these screws which pass through the upper portion
of the stock into the cutters, the latter can be adjusted. to a perfect level
transversely with the carriage B on which the stone rests, and exactly on a level
with each other in order to ensure a cut of uniform depth at each traverse of
the carriage, and a uniform action over all portions of the surface of the stone,
which is thus given a uniform level surface, as required, to produce perfect work.
The projections vw are made adjustable in the direction of the length of the
framework by means of nuts 25 and bolts d², the heads of the latter being adapted
to slide in a dovetailed groove e² in the side of the carriage B. By means of this
adjustment the rocking of the shaft H can be effected at any desired part of the
traverse of the carriage B to reverse the direction of its motion when the end of
the stone is reached by the cutters, the point where the removal occurs depending
upon the length of the stone upon the carriage.
When it is desired to raise the cross head K with its cutters to accomodate stones
of varying thicknesses, or for any other purpose, it is merely necessary to disconnect
the pawls f¹g from the ratchet wheel e¹ when the shaft M can be turned by
means of a crank handle or wheel applied to one end, and the cutters thus raised.
to the desired height.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that

page_text: I claim in a machine for planing or dressing the surfaces of lithographic and other,
soft stones:-
→
First. The combination with the reciprocating carriage B for supporting the
stone to be planed, of the oscillating cutter-stock P pivotted to the cross-head K
and provided with a pair of cutters q¹, 71 adapted to be alternately brought into
contact with the stone at opposite ends of its traverse; the toothed segments s¹ t¹,
the shaft u', the lever a², the rod 62, the lever N, and means substantially as
described, for. oscillating the said lever N at each traverse of the carriage, all
constructed to operate substantially in the manner and for the purpose described.
Second. The combination with the vertically movable cross head K sliding in
slots in the standards I, and provided with an oscillating cutter stock P having a
pair of cutters q r adapted to be aternately brought into contact with the stone
at opposite ends of its traverse, of the screw shafts 61 adapted to support the cross
head and provided at their upper ends with worm gear wheels c rotated by
worms d on the horizontal shaft M located above the cap piece L, the ratchet
wheel e' on the shaft M rotated by the pawls f¹, g on the levers h¹¹ oscillating
upon the shaft M, and connected by rods k¹ with the lever N on the rock shaft,
-the lever u on the said shaft H and the projections won the carriage B adapted
to vibrate the lever u alternately in opposite directions, all constructed and
arranged to operate substantially in the manner and for the purpose described.
Third. The combination with a rocking cutter stock P supported within the
cross-head K, of the two cutters q¹¹ extending transversely across the entire
width of the carriage B and each made adjustable vertically at different portions of
its length by means of screws c² whereby each cutter can be adjusted to a perfect
level transversely with the carriage, substantially as set forth.
Fourth. The combination of the reciprocating carriage B, the oscillating cutter
stock P pivotted to the cross head K and provided with the cutters q¹ 1; means
substantially as described for oscillating the cutters; the shaft H connected with
the mechanism for oscillating the cutters and operated by the projections v won
the carriage B; the lever t secured to the shaft H and provided with a slot 15;
the connecting rod s; the bar sliding in standards above the pulleys g and h;
and the belt shippers m n secured to the sliding bar r, all constructed, and arranged
to operate, substantially in the manner and for the purpose described.
· Dated this 4th day of March 1884.