IMPROVEMENTS IN CARRIERS, DOGS, OR DRIVERS FOR TURNING-LATHES
Year: 1880

page_text: It
LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention of
IMPROVEMENTS IN CARRIERS, DOGS, OR DRIVERS FOR TURNING-LATHES."
A communication from abroad by John Hill, of Columbus, Georgia, United
States of America, Civil and Mechanical Engineer.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 22nd June 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, and Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN CARRIERS, DOGS, OR
DRIVERS FOR TURNING-LATHES." [A communication from abroad by John Hill,
of Columbus, Georgia, United States of America, Civil and Mechanical Engineer.]
This Invention relates to lathe dogs or drivers, and it is especially designed for
driving pieces to be turned, such as the faces or edges of light-armed metal pulleys
or other like articles, where the webs or arms between the central hub and outer
surfaces are light and of insufficient strength to afford the requisite steadiness when
the tool comes in contact with the rim. With the ordinary mandrel and lathe-dog
such articles in turning vibrate and cause the tool to "chatter," so much that owing
to the difficulty in turning off the outer surfaces, there is a limit to the reduction of
the strength of the arms of such pulleys and the like, whereas the proportions of
the same might otherwise be consideraby reduced for all practical purposes.
To remedy this defect I propose to employ two or more lathe dogs in connection
with a face-plate in such manner that the pulley or other article to be turned is
driven equally by each dog in the system, the bearings of the said dogs being at
points near the rim of the pulley, thereby throwing the driving strain from the
pulley-arms on the compound dogs.
To this end the said Invention comprises :-Providing the pivotted radial arms.
of the lathe-dogs with sliding dogs adapted to be automatically adjusted in pulleys
or other like articles; also, the radial dog-arms connected upon the face-plate by
spindles with crank-arms-which-are-set-at-angles to the radial-dog-arms, so-as-to-be-
Dmine G21

page_text: in position for acting upon a plain or cam-shaped movable band or rim or a toggle;
also, the combination of the pivotted arms having crank-arms with a loose ring
arranged to be shifted upon the face-plate until all of the dogs upon the radial
arms are in contact with the arms of the article to be turned, at which period the
ring will be held stationary and the crank arms be fixed by their opposing forces 5
against the ring; also the general combination and arrangement of the parts, as
hereinafter described.
In carrying the said Invention into practice I employ, say, three dogs or drivers,
which are applied to a face-plate provided with an internally screw-threaded hub,
by means of which it is screwed upon the live spindle of an engine lathe. This
face plate may be of any proportionate diameter within the "swing." When three
dogs or drivers are to be used I lay off a circle upon the face-plate, taking the
centre of the spindle as its centre, making this circle for small face-plates as near to
the hub of the face-plate as practicable. The circle is then divided into three equal.
parts, and at each point of division I drill a hole through the face-plate to receive
a spindle. When the face-plate is of insufficient thickness to furnish the requisito
length of bearing for the spindle, the plate may be formed with bosses or hubs,
through which the spindles will also pass, and thus have the required bearing surfaces.
To each spindle is rigidly secured a radial arm arranged parallel with the face of the
plate. Upon each one of these radial arms is fitted a slide from which projects to a
considerable length a dog, preferably arranged to project out from one end of the
slide, so that the slide may be detached from the radial arm and reversed, in order
that in again fitting it upon the radial arm the dog may be brought nearer to or
farther away from the centre of the face-plate as required. These slides are also
secured in position upon the radial arms with relation to the diameter of the wheel
to be turned by means of set-screws.
To the reverse end of each spindle which projects out from the other side of
the face-plate I rigidly secure a crank-arm, which is preferably set at an angle of
about 90 degrees to that radial arm which is upon the same spindle. To the outer
end of each crank-arm is secured a stud extending toward the face-plate, and to
reduce friction each stud is provided with a friction-roll, although a solid stud may
be employed and the friction-roll dispensed with. Surrounding these three friction-
rolls or studs is a loose metal ring, of such diameter that when each friction-
roller or stud of the crank-arms is moved out from the hub to about one third
of a circle, the ring and studs or friction-rollers will be in contact with each
other. In some cases, where there is sufficient space, this ring may be arranged
insido of the friction-rollers or studs instead of outside.
The ring is by preference made flat, and it is arranged loosely upon the face-plate,
so that it may be shifted to a considerable extent without coming in contact with
any stop other than the friction rolls or studs. It is held upon the face-plate by
metal strips or bars, which are secured at their outer ends to a circumferential
flange, and at their inner ends to studs upon the face-plate, space being left
between the face-plate and these strips for the free movement of the ring. The
ring in the present example is made of a circular forn with plain inner and
outer edges, although in place of such there may be substituted a cam-ring having
several irregular curved surfaces, which would answer substantially the same
purpose; or if desired a toggle having as many links as there are radial arms
might be employed, the links being pivotted together at their ends and to the
ends of the crank arms by means of the studs.
The number of dogs is not necessarily limited to three. If two arms with their
attachments and one ring are employed, the relative angle of the radial arm to
the crank-arın can be changed from 90 to 180 degrees. If four sets are employed
90 degrees may be allotted to each, and if five radial arms are used, then
7.2 degrees will be about the proper angle.
In very light work it will sometimes be necessary to change the form of the
plain ring to a ring having cam-shapes of appropriate forms, so as to cause the
thrust of the cranks to adjust the prongs of the radial dog-arms more delicately

page_text: against the arms of the pulley, though for the heavier class of work, especially
in compound dogs of from two to four arms, the round ring is preferable, both
for simplicity and for facility in changing its bearings upon the friction rollers or
studs of the crank-arm.
In the compound lathe-dog herein described the cranks are arranged upon the
rear side of face plate. It is evident however that they might be arranged upon
its front face whereon the sliding dogs are located, and thus operate in conjunction
therewith. Also, for a certain class of work the slides and their dogs could be
replaced by dogs secured directly to the radial arms. The device can be attached
to the live spindle of the lathe, as hereinbefore mentioned, or it can be attached
directly to the mandrel, the central hole being in the latter case of sufficient size to
pass over the mandrel bushings, set-screws being usually employed to secure it in
place.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 21st
December 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, and Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN CARRIERS, DOGS, OR
DRIVERS FOR TURNING-LATHES." A communication from abroad by John Hill,
of Columbus, Georgia, United States of America, Civil and Mechanical Engineer.
This Invention relates to lathe dogs, carriers, or drivers, and it is especially designed
for driving pieces to be turned, such as the faces or edges of light aried metal pulleys
or other like articles, where the webs or arins between the central hub and outer
surfaces are light and of insufficient strength to afford the requisite steadiness when
the tool comes in contact with the rim. With the ordinary mandrel and lathe dog
such articles in turning vibrate and cause the tool to "chatter," so much that owing
to the difficulty in turning off the outer surfaces, there is a limit to the reduction of
the strength of the arms of such pulleys and the like, whereas the proportions of
the same might otherwise be considerably reduced for all practical purposes.
To remedy this defect I propose to employ two or more lathe dogs in connection
with a face plate in such manner that the pulley or other article to be turned is
driven equally by each dog in the system, the bearings of the said dogs being at
points near the rim of the pulley, thereby throwing the driving strain from the
pulley arms upon the compound dogs.
To this end the said Invention comprises: Providing the pivotted radial arms
of the lathe dogs with sliding dogs adapted to be automatically adjusted in pulleys
or other like articles; also, the radial dog arms connected upon the face plate by
spindles with crank arms which are set at angles to the radial dog arms, so as to be
in position for acting upon a plain or cam shaped movable band or rin or a toggle;

page_text: also, the combination of the pivotted anns having crank arms with a loose ring
arranged to be shifted upon the face plate, until all of the dogs upon the radial
arms are in contact with the arms of the article to be turned, at which period the
ring will be held stationary, and the crank arms be fixed by their opposing forces
against the ring; and also, the general combination and arrangement of the parts,
as hereinafter set forth.
In the accompanying Drawing,―
Figure 1 is a perspective view of my improved compound lathe dog when
in use.
Figure 2 shews a face view of the compound dog looking through the pulley
which is being operated upon, and also shows a cross-section of the mandrol
supporting the pulley.
Figure 3 is a perspective view of the compound lathe dog detached, and
Figure 4 is a rear elevation of the same.
Figure 5 is a central section of the said compound lathe dog.
Figure 6 is a rear elevation of the compound lathe dog provided with a toggle in
lieu of a loose ring.
Figure 7 is a rear clevation of the compound lathe dog provided with a
cam-shaped loose ring.
In the compound lathe dog illustrated in the Drawing three dogs or drivers are
shewn. These dogs are applied to a face plate A provided with an internally scrow
threaded hub B, by means of which it is screwed upon the live spindle of a lathe,
as shewn in Figure 1, in which m designates the live spindle. This face plate may
be of any proportionate diameter within the “swing." When three dogs or drivers
are to be used I lay off a circle upon the face plate, taking the centre of the spindle
as its centre, making this circle for small face plates as near to the hub of the faco
plate as practicable. The circle is then divided into three equal parts, and at each
point of division I drill a hole through the face plate to receive a spindle C. When
the face plate is of insufficient thickness to furnish the requisite length of bearing
for the spindle, the plate may be formed with bosses or hubs, through which the
spindles will pass, and thus have the required bearing surfaces. To each spindle C
is rigidly secured a radial arm D arranged parallel with the face of the plate.
Upon each one of these radial arms is fitted a slide E, from which projects to a
considerable length a dog G, preferably arranged to extend out from one end of the
slide, so that the slide may be detached from the arm D and reversed, in order that
in again fitting it upon the radial arm the dog may be brought nearer to or farther
away from the centre of the face plate as required. These slides are also secured in
position upon the radial arms with relation to the diameter of the wheel to be
turned by incans of set screws E¹.
To the reverse end of each spindle which projects out from the other side of the
face plate I rigidly secure a crank-arm F, which is preferably set at an angle of
about 90 degrees to that radial arm which is upon the same spindle. To the outer
end of each crank arm is secured a stud f extending toward the face plate, and to
reduce friction each stud is provided with a friction roll G', although a solid stud
may be employed and the friction roll dispensed with. Surrounding these three
friction rolls or studs is a loose adjustable metal ring or annular stop H of such
diameter that when each friction roller or stud of the crank arms is moved out
from the hub to about one third of a circle, as illustrated in Figure 4, the ring and
studs or friction rollers will be in contact with each other. In some cases, where
there is sufficient space, this ring may be arranged inside of the friction rollers or
studs instead of outside, as shewn.
The ring is by preference made flat, and is arranged loosely upon the face plate, so
that it may be shifted to a considerable extent without coming in contact with any
stop other than the friction rolls or studs. It is held upon the face plate by metal
strips or bars I, which are secured at their outer ends to the circumferential
flange K, and at their inner ends to studs L upon the face plate, space being left
between the face plate and these strips for the free movement of the ring.

page_text: The ring in the present example is shewn of a circular form with plain inner and
outer edges, although in place of such a ring there may be substituted a cain-ring
having several irregular curved surfaces, as shewn at H' in Figure 7, which would
answer substantially the same purpose; or if desired a toggle having as many links
5 as there are radial arms might be employed, as illustrated in Figure 6, in which
h, h, h, designate the links of the toggle which are pivoted together at their ends
and to the ends of the crank arms by means of the studs f.
The operation of the devices is ns follows:-
The pulley or like article to be turned is first bored out as usual and fitted to a
mandrel near one end thereof, as shewn in Figure 1, in which n indicates the
mandrel, and o, o', the lathe centres. The mandrel with the pulley is placed
between the lathe centres in such a position that each dog will be out from the hub
of the face plate about one third of a circle, and at the back of the arms of the
pulley to be driven. When the lathe is started and the lathe tool acts upon the
surface to be turned, it prevents the pulley froin revolving until one arm of
the pulley is engaged by one of the dogs. The lathe power causes the radial arm
of the dog to move backward, and this moves its crank arm, which in turn acts
upon the ring so as to move it to one side of the centre of the face plate. The ring
during such movement bears upon the friction rolls or studs of the remaining crank
arms, and causes a second dog to move in an opposite direction to the one just
described, until said second dog engages with the next arm of the pulley.
The two dogs now in engagement with the two pulley arms will both be moved
backward, thus moving the ring in a direction to act upon the friction roll or stud
of the crank arm of the third dog, which will then be caused to move in a
direction opposite to the movement of the first two dogs, until said third dog
likewise engages an arm of the pulley.
The ring, being now acted upon by three forces equally, as illustrated in
Figures 1 and 2, where the dogs G aro shewn in contact with the arms of a pulley
to be turned, will remain fixed in its position, and the driving will become positive
with regard to any forward movement of the lathe and pulloy against the lathe tool.
From the above description it will be understood that the number of dogs is not
necessarily limited to three. If two arms with their attachments and one ring are
employed, the relative angle of the radial arm to the crank arm can be changed
froin 90 to 180 degrees. If four sets are employed 90 degrees may be allotted to each,
and if five radial arins are used, then 72 degrees will be about the proper angle.
In very light work it will sometimes be necessary to change the form of the
plain ring to a ring having a cam shaped configuration, as in Figure 7, or a ring of
any other appropriato forin, so as to cause the thrust of the cranks to adjust the
prongs of the radial dog arms more delicately against the arms of the pulley,
though for the heavier class of work, especially in compound dogs or from two to
four arms, the round ring herein shewn is preferable, both for simplicity, and for
facility in changing its bearings upon the friction rollers or studs of the crank arm.
In the compound lathe dog herein described and shewa in the Drawing the
cranks are arranged upon the rear side of the face plate. It is evident however
that they might be arranged upon its front face whereon the sliding dogs are
located, and thus operate in conjunction therewith. Also, for a certain class of
work the slides and their dogs could be replaced by dogs secured directly to the
radial arms. The device can be attached to the live spindle of the lathe, as
herein before mentioned, or it may be attached directly to the mandrel, the central
hole being in the latter case of sufficient size to pass over the mandrel bushings, set
screws being usually employed to secure it in place.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
First. In a compound lathe dog, the combination of the face plate with the sliding
dogs adjustably connected to pivotted radial arms, and a common automatically

page_text: adjustable stop acted upon by all of the arms, substantially as and for the purpose
specified.
Second. In a compound lathe dog, the combination of the face plato with a series
of radial arms connected by spindles with crank-arms, which aro set at angles
to the radial arms, and a ring held loosely upon the face plate and arranged to be
acted upon by all of the said arms, substantially as set forth.
Third. In a compound lathe dog, the combination with a face plate of a series of
pivoted arms having crank-arms, and a loose ring or a toggle arranged to be
shifted upon the face plate in the manner set forth, and to hold the dogs fixed in
the required position so as to ensure a positive driving after their adjustment,
as above specified.
Fourth. The combination of a loose ring, as herein described, held upon the face
plate of a lathe with the spindles C having their bearings in the face plate, tho
radial arms D and the crank-arms F secured to the spindles, the dogs G connected
with the radial arms, and the studs with anti-friction rollers secured to the crank
arms, substantially as set forth.
Fifth. The combination of a loose ring or a toggle, as herein described, held upon
the face plate of a lathe with the spindles having their bearings in the face plate,
the radial arms and the crank-arins secured to the spindles, the dogs connected
with the radial arms, and the studs f secured to the crank armis, substantially as
herein described.
Sixth. The combination of the face plate with the radial arms D and the crank-
arms F secured to spindles C, the dogs G secured to slides fitted upon the radial
arms, and provided with set-screws to hold them in place upon the said radial
arms, and the loose ring H, or a cam-shaped ring, or a toggle acted upon by the
crank arms, as herein specified.
In witness whereof, I, the said William Robert Lake, havo hereunto set my
hand and seal, this Twenty first day of December, in the year of our Lord
One thousand eight hundred and eighty.