Year: 1893

page_text: Date of Application, 1st May, 1893-Accepted, 15th July, 1893
Fig. 3 a side view,
Fig. 4 the use of the plate in a drilling machine for milling single pivots;
Figs. 5 to 8 the combination of two milling plates for producing two concentric
opposite pivots as occurring in bow handles,
Fig. 9 a section through the holes for starting the pivots,
Fig. 10 a handle on which the pivots shewn on Fig. 11 are to be milled.
The milling plate shewn by Figs. 1 and 3 can be used on drilling machines as
shewn by Fig. 4 or fixed on the slide rest of a lathe. The upper side of the milling
plate A is formed with sharp concentric ridges a and corresponding grooves a¹ and
contains one or more holes b which are tapered wider at the top of the plate and
provided with internal teeth c. In this the ends of the bars on which pivots are
to be formed are first milled and reduced in size at the end, so that they can enter
and be guided by the internally smooth holes d, which are made in various sizes
corresponding to the desired diameters of the pivots, and finish a cylindrical sharp
shouldered pivot. The bar or rod on which the pivot to be formed is fixed in
the socket e of the spindle of a drilling machine C in the same way as a drill and
fed against the milling plate A till the desired length of the pivot has been
obtained.
If two opposite conaxial pivots are to be formed two conaxially arranged milling
plates A A, Figs. 5 to 9, are arranged provided with concentric ridges and grooves
as described on their outside face, and pressed outwards or apart (Fig. 7). For
this purpose the milling plate A¹ is fixed or formed on a hollow sleeve g containing
a spring which presses against a pivot or spindle i of the plate A. The pivot i
is held and guided in the sleeve g by a pin l'entering a slot k of said sleeve. For
milling the pivots on the ends of a swivelling handle D, the ends are first brought
into the pointing holes b by pressing the plates A and A¹ together so that the
bandle D can clip both plates. When plate A is released, the handle D holds
with its ends the plates A A¹ under pressure. By a to and fro movement of the
bandle D (Fig. 8) the pivots are pointed, and after transfer of the handles to the
hole of the desired diameter the pivots are finished in the same way.
The improved milling plate has the advantage that it can be very easily and
cheaply made, and its surface can be utilised for a number of different sizes of
pivots.

page_text: In place of the spring for pressing the plates A A' apart for forming opposite
pivots any other equivalent arrangement for this purpose may be used producing a
constant pressure on the ends m n of the handle when milling the pivots f, for
instance combinations of levers and weights or equivalent means.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :
1. The manufacture and use of milling plates for milling pivots made by turning
sharp edged concentric ridges a and corresponding sharp grooves into a disc, and
drilling holes (d) of various diameters into the same corresponding to the diameters
of the pivots to be produced, one or more of which holes (b) may be tapered and
provided with internal teeth (c) for starting the pivots, substantially as herein before
described and illustrated in and by the drawings.
2. For producing two opposite conaxial pivots the combination of two milling
plates (AA) having the same axis and provided on their outsides with pivot
milling teeth and holes and pushed apart by a spring or equivalent means in such a
manner that when the ends of a handle D or equivalent piece are placed into the
holes for starting or into the holes d for finishing the pivots, the plates A A' are
pressed against the ends of (m n) of said handle or piece and the two pivots can
be started and finished simultaneously by imparting a to and fro motion to said
handle or piece, substantially as hereinbefore described and illustrated by the
drawings.
Do In of A11002
R. J. URQUHART,
57, Barton Arcade, Manchester, and 5, Clayton Square, Liverpool,
Consulting Engineer and Patent Agent.