Year: 1887

page_text: Date of Application, 24th Aug., 1887
Complete Left, 25th Jan., 1888
Complete Accepted, 6th Apr., 1888
We JOSEPH LINDSAY, and ROBERT ALLAN, of Blackness Foundry, Dundee, in the
County of Forfar, North Britain, Engineers, do hereby declare the nature of this
Invention to be as follows, that is to say :-
Our said Invention has for its object to improve the shaping of the teeth of bevil
wheels when such teeth are made with inclinations to the planes passing through the
axis of the bevil wheel or relative cone. Such teeth are generally made each with
one half inclined the reverse way of the other half; and ordinarily each half has
been made with its acting surfaces straight or nearly so, or otherwise of an imperfect
form, and so as to cause imperfect action between two such wheels gearing together.
By our Invention we shape the teeth so that each half of each tooth is made as nearly
as is practicable of a true conoido-helical form and of a correct taper. With such forms
two of such wheels will gear correctly together with the surfaces of the teeth bearing
as completely as truly-helical spurwheel teeth, and with great regularity and smooth-
ness in working.
In carrying out our Invention we make patterns for making moulds in which to
cast the bevil wheels, each complete pattern corresponding to a complete wheel. Or
we make a pattern for only one or two teeth and form the mould with the aid of
apparatus of a kind in use, by means of which the several teeth of a wheel are
moulded successively. In all cases the pattern for one half of a tooth or for the
halves of a series of teeth, is shaped or cut out separately from the pattern for the
other half or halves, so that the cutters employed may work beyond the ends of
the half teeth. The halves are subsequently fixed.. together on a plate or web, care
being taken to adjust them accurately to each other.
For cutting the teeth patterns we employ a special modification of the machinery
described in our Patent Specification No. 4122 of 1878. In this modification, whilst
giving the same motions as formerly to the cutter, we in addition give a reciprocating
angular or partial rotatory motion to the part carrying the pattern, the combined
motions of the two parts giving the conoido-helical form to the teeth as desired.
Our Invention may also be applied when the conoido-helical teeth are made not
with one half of each at an angle to the other half but with the whole of each tooth
inclined the same way.
Dated this third L
Ր A
1007
EDMUND HUNT,
Applicants' Agent,

page_text: COMPLETE SPECIFICATION.
Improvements in Shaping the Teeth of Bevil Wheels.
We, JOSEPH LINDSAY, and ROBERT ALLAN, of Blackness Foundry, Dundee, in
the County of Forfar, North Britain Engineers do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement, that is to say :—
Our said Invention has for its object to improve the shaping of the teeth of bevil
wheels when such teeth are made with inclinations to the planes passing through the
axis of the bevil wheel or relative cone. Such teeth are generally made each with
one half inclined the reverse way of the other half; and, ordinarily, each half has
been made with its acting surfaces straight or nearly so, or otherwise of an imperfect
form, and so as to cause imperfect action between two such wheels gearing together.
By our Invention we shape the teeth so that each half of each tooth is made, as
nearly as is practicable, of a true conoido-helical form, and of a correct taper. With
such forms two of such wheels will gear correctly together with the surfaces of the
teeth bearing as completely as truly-helical spurwheel teeth, and with great regularity
aud smoothness in working.
In carrying out our Invention we make patterns for making moulds in which to
Or
cast the bevil wheels, each complete pattern corresponding to a complete wheel.
we make a pattern for only one or two teeth, and form the mould with the aid of
apparatus of a kind in use, by means of which the several teeth of a wheel are
moulded successively. In all cases the pattern for one half of a tooth or for the
halves of a series of teeth, is shaped or cut out separately from the pattern for the
other half or halves, so that the cutters employed may work beyond the ends of
the half teeth. The halves are subsequently fixed together on a plate or web, care
being taken to adjust them accurately to each other.
For cutting the teeth patterns we employ a special modification of the machinery
described in the Specification of Patent No. 4122 of 1878 granted to William Walter
Urquhart, and Joseph Lindsay (the latter being one of the present applicants). In
this modification whilst giving the same motions as formerly to the cutter, we in
addition give a reciprocating angular or partial rotatory motion to the part carrying
the pattern, the combined motions of the two parts giving the conoido-helical form
to the teeth as desired.
On two accompanying sheets of explanatory drawings, figures, 1, and 2, are a plan
and a side elevation which are the same as similar figures of the drawings of the
earlier Specification hereinbefore referred to, excepting alterations or additions made
for the purposes of the present Invention. The unaltered parts are marked by the
same reference numerals as in the said earlier Specification and the altered parts are
marked by reference letters.
On the main spindle or mandrill; 11, of the machine there is set loosely a pattern
carrier, A, made with two arms, B, C, on one, B, of which there is fixed a pièce, D,

page_text: of wood or other suitable material to be operated on by the cutter, 27, so as to be
shaped into one or more conoido-helical half teeth. The other arm, C, of the pattern
carrier has formed or fixed on it a cylindrical segment or arc, E, to which there are
attached two steel bands, one, F, fixed to the top of the segment being drawn down
directly by a weight, G, and the other, H, being passed over a pulley, J, and fixed
to a weight, K, so as to tend to draw the segment upwards. The pulley, J, (to which
the band, H, passing round it is fixed by a screw pin) is fixed on a horizontal shaft, L,
carried partly by a forked horizontal arm, M, which is adjustable in a bracket, N, the
pulley, J, being between the fork prongs of the arm. The horizontal shaft, L, has
fixed on it near its inner end a saucer-shaped pulley, P; and a small ball is formed
on the extreme end of the shaft, the centre of which ball is in the plane passing
through the middle of the rim groove of the pulley, P. The spherical end of the
horizontal shaft, L, is, as shown in the enlarged horizontal section, figure, 3, centered
in one or other of two bearings, Q, accordingly as a right-hand or left-hand helix is
being formed on the pattern. The bearings, Q, are formed in a bracket, R, fixed to
the centre block, 30, adjustably fixed to the beam, 29, and carried on the main centre
ball, 25, of the machine. A steel band, S, fixed to the saucer-shaped pulley, P, passes
down through a hole in the base of the bracket, R, also through a hole in the
block, 30, and round a guide pulley, T, fitted in a recess in the block, 30, the band
proceeding from the pulley, T, to the cutter block, 28, to which last its end is
adjustably fixed. When the cutter block, 28, moves in the direction from the centre
of the machine it draws the band, S, and by means of it turns the pulley, P, and
shaft, L, which last through the pulley, J, and band, H, either lowers or draws up
the segment, E, of the pattern carrier, A. An angular or partial rotating motion is
thus given to the pattern, D, simultaneously with the rectilineal motion of the
cutter, 27, and the two motions combining produce the desired conoido-helical form
of tooth. If the inner end of the horizontal shaft, I, is shifted from one bearing, Q.
to the other, the band, S, will be adjusted to proceed down from the other side of the
saucer-shaped pulley, P, with the result that the angular movements of the pattern
carrier, A, will be reversed so that the helix formed will be left-hand instead of
right-hand or vice versa. Figure, 4, is a diagram showing on a cone representing
the pitch cone of a bevil wheel, two conoido-helices portions of which give the proper
shapes for the half teeth of a bevil wheel according to our Invention.
Our Invention may also be applied when the conoido-helical teeth are made not
with one half of each at an angle to the other half, but with the whole of each tooth
inclined the same way.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed, we declare that what
we claim is :-
1-Making the teeth of bevil wheels of a conoido-helical shape substantially as
hereinbefore described.
2-Making the teeth of bevil wheels of a conoido-helical shape by means of
machinery substantially such as is herein before described and shown in the accom-
panying drawings.
Dated this Twenty-fourth day of January 1988
EDMUND HUNT,
Applicants' Agent.