IMPROVEMENTS IN MILL STONE ATTACH- MENTS
Year: 1878

page_text: LETTERS PATENT to Herbert John Haddan, of the Firm of Herbert and
Company, Solicitors of Patents, of 67, Strand, in the City of Westminster,
Civil Engineer, for the Invention of "IMPROVEMENTS IN MILL STONE ATTACH-
MENTS."
A communication from abroad by William Johnson, of Milwaukee,
United States of America”
Sealed the 20th June 1879, and dated the 31st December 1878.
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at
the Office of the Commissioners of Patents on the 31st December 1878.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. IMPROVEMENTS
IN MILL STONE ATTACHMENTS." A communication from abroad by William
Johnson, of Milwaukee, United States of America.
The improvements relate to that part of a mill stone attachment commonly
called a driver, and are constructed on the general plan of the present slip driver,
but in such manner that the difficulties in the use of said driver are overcome. The
improvements consist in or of a metal driving link resting upon metal rollers fixed
in the lower or bed plate of the driver, said link being provided with lignum vitæ,
or other facings, which slide upon the upper or cover plate. The lower plate is cast
with a high annular rim extending up through the upper or cover plate, the
interior of which rim fits the driving spindle. The link slides backwards and
forwards upon the bed plate, and is guided by lugs faced with boxwood.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Herbert John Haddan in the Great Seal Patent Office on the
27th June 1879.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. "IMPROVEMENTS
IN MILL STONE ATTACHMENTS." A communication from abroad by William
Johnson, of Milwaukee, United States of America.
The mill stone attachment or driver is constructed on the general plan and
method of the well known "slip driver" long known and used, but obviates the
difficulties met with in the use of that driver. In the Drawing, Figure 1 represents the
driver with its cover M (Figure 4) removed; Figure 2 shows the lower plate; Figure 3
shows a side view of the driver complete; Figure 4 shows the cover plate; E is the
driving link constructed preferably of malleable iron of the general form shown in
Figure 1. It rests upon hardened steel rollers N, N, N, N, fixed in the lower or
bed plate of the driver. At the points where the link rests upon N, N, it is faced
with hardened steel bearings O. Upon its upper face it is provided with lignum
vitae, or other suitable facings L, L, L, L, which slide upon the upper or cover
plate. The lower plate A is cast with a high annular rim extending up through
the upper or cover plate D, D. The interior of this rim fits the driving spindle;
Link E slides
Q, Q, are projections to which the attaching screws fasten the cover.
back and forth upon the bed plate in a direction passing through the middle of the
jaw slots, and is guided by means of lugs B, B, faced with box wood fitting into
recesses in the lower face of link E, which are provided with brass facings
P, P, P, P. The bearing jaws of the link E are provided with oscillating dogs F, F,
shown in detail in Figures 5 and 6; F is the movable dog provided with hinge
ears K hinging it to E by means of hinge bolt G, as shown in the Drawing.
A rubber cushion closely compressed is placed between F and E, so that it yields
only under considerable pressure. The face of the jaws H is faced with steel pre-
ferably, and the ends of the mortice or rim in the centre of the driver are also faced
with steel. The operation of the improved driver is as follows:-The spindle
passing up through the opening in the centre of the driver to which it is fitted
accurately causes it to revolve, and the jaw dogs F, F, coming in contact with the
ball of the running mill stone link E, slide upon its bearings until they arrive at a
point where the jaws bear equally against the ball, the stone is thus driven steadily,
and when the spindle is out of train, the link will slip and thus allow the upper
stone to run parallel with the lower stone. The clastic backing and peculiar
adjustment of the jaws prevents the vibration and trembling that would otherwise
occur. I claim. 1. The link E provided with dogs F, F, pivoted to the same, so as
to rock up and down, substantially as described. 2. The lower plate A provided
with raised ring D and projections B, B, in combination with link E and dogs F, F,
substantially as described. 3. Link E provided with dogs F, F, pivoted so as to
oscillate up and down in combination with the yielding substance O to prevent
vibration, substantially as described. 4. Lower plate A and rollers in combination
with link E, substantially as specified.
In witness whereof, I, the said Herbert John Haddan, have hereunto set my
band and seal. this Twenty third day of June, A.D. 1879.