Improvements in Collier's Two Speed Gear
Year: 1896

page_text: Date of Application, 8th Oct., 1896
Complete Specification Left, 7th Aug., 1897-Accepted, 11th Sept., 1897
Improvements in Collier's Two Speed Gear, Patents Nos. 8893/89
and 13234/93.
I, JOHN POLLITT of 63 Warley Road, Claremont Park, Blackpool in the County of
Lancaster Cycle Manufacturer do hereby declare the nature of this invention to be as
follows:-
In Collier's Two Speed gear the mechanism for changing from one gear to the
other consists of a bolt sliding through the eccentric axle and in the one case engaging
with a slot or hole in the annular wheel or pinion disc causing the two parts to revolve
together as one piece to give the low gear, and in the other case sliding out of the
slot or hole and allowing the annular wheel or pinion to revolve on its own axis, to
give the higher gear. In the second case the eccentric axle is held so as not to
revolve and becomes the bearing for the annular wheel or pinion axle. This axle is
held by the projecting head of the bolt engaging in a slot cut on the highest part of
an inclined plane, the bolt head taking all the strain of driving at the higher gear.
The difficulty being to fit the head of the bolt sufficiently free to slide, and yet so
firmly that it will not shake when holding the axle against the driving strain. Also
the constant driving causes the head of the bolt to work loose in its guide. My
Invention relates to the method of withdrawing this bolt, and to the method of
holding the eccentric axle. The bolt is constructed upon similar lines to Collier's
but with an inclined plane upon the projecting head set at right-angles to the length
of the bolt. The head of the holt runs or slides in a slot cut out of the solid metal
of the eccentric axle, or secured firmly to the same by brazing, screwing, or other
recognized mechanical means. In order to cause the bolt to slide and so withdraw
the end from the pinion or annular wheel disc it is only necessary to bring in contact
with the toe or thin part of the inclined plane a simple plunger, by preference of
square steel, and sliding on or guided from the bottom bracket or framework carrying
the two speed gear. When the eccentric axle revolves and the plunger is allowed to
strike the inclined plane the bolt is withdrawn from the pinion or annular wheel disc
and the pluger at this moment engages in the slot in which the bolt slides, thus
taking all driving strain off the bolt head and holding the eccentric axle by direct
contact without the aid of intermediate mechanism, and avoiding looseness or rattle
in the bolt by wear, as exists in Collier's Invention. The inclined plane on the head
of the bolt may be a double one so that the bolt may be withdrawn when the
eccentric axle is running (or revolving) either backwards or forwards. The invention
may be applied either between the ball races of the eccentric axle or at the projecting
end outside the ball races. The advantage of applying inside being that it is enclosed
by the casing of the carrying bracket and protected from dust or wet, and that by
dispensing with the projecting end to the eccentric axle the tread or width of such
xle is reduced without reducing the distance between the ball races or bearings.

page_text: COMPLETE SPECIFICATION.
Improvements in Collier's Two Speed Gear, Patents Nos. 8893/89
and 13234/93.
I, JOHN POLLITT, late of 63 Warley Road, Claremont Park, Blackpool, now of
Clifton Drive, Fairhaven near Lytham, do hereby declare the nature of this inven-
tion and in what manner the same is to performed to be particularly described and
ascertained in and by the following statement:-
In Collier's two-speed gear as described in his specifications, as aforesaid the
mechanism for changing from one gear to the other consists of a bolt sliding through
the eccentric axle, and in the case of one gear (say for the lower speed) engaging
with a slot or hole in the annular wheel or pinion, causing the two parts to revolve
together as one, and in the other case, (say for the higher speed) sliding out of the
said slot or hole and allowing the annular wheel or pinion to revolve on its own
axis.
In the second case the eccentric axle is held fast so as not to revolve and becomes
a bearing in which the axle of the annular wheel or pinion revolves. This axle is
held fast by the projecting head of the bolt engaging in a slot cut in the highest
part of an inclined plane, and this takes all the strain when driving at the higher
speed.
The difficulty being to fit the head of the bolt sufficiently free to allow it to slide,
and yet so firmly that it will not shake when holding the axle against the driving
strain. Also the constant driving causes the head of the bolt to work loose in its
guide.
My improvements are designed to obviate these difficulties, and relate principally
to the method of withdrawing this holt and the method of holding the eccentric
axle.
The nature of my improvement and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference to
the sheet of drawings hereunto annexed and the following explanation thereof :-
Fig. 1. on the drawings is a longitudinal section through the Collier two-speed
gear with my improvement shown as applied thereto.
Fig. 2. is a vertical, transverse section through about the line A-B in Fig. 1.
Fig. 3. a vertical, transverse section through about the line C-D.
Fig. 4. is a plan view of the eccentric axle and its adjuncts showing the bolt
locking the annular wheel thereto, and Fig. 5. shows the same released.
a is a barrel of the bottom bracket which supports the whole gear,
b the eccentric axle,
d the sliding bolt, and
e the annular wheel or pinion fixed to, or formed with, the crank spindle c.
The sliding bolt d is constructed on similar lines to Collier's but it is provided
with a double inclined plane f upon or fixed to the projecting head d. set at right
angles to the length of the bolt as seen at Figs. 4 and 5. The head dx of the
bolt slides in a slot cut out of a solid metal projection b* forming part of the eccentric
axle b or secured firmly to the same by brazing, screwing, or by other recognized
mechanical means.
In order to cause the bolt d to slide so as to withdraw its end from the hole in
the disc of the annular wheel or pinion e it is only necessary to bring into contact
with the toe of the inclined plane fa plunger g preferably of square steel which
slides in a groove made through a solid part of the bottom bracket or barrel a.
When the eccentric axle b is revolving and the plunger g is placed in such a
position as to act upon the inclined plane f the sliding bolt d is withdrawn as shown

page_text: at Fig. 5 from the disc of the annular wheel or pinion e and the end of the plunger g
at this moment engages in a slot in the solid projection bx in which the head d
of the bolt d slides, thus relieving the head of the bolt from all driving strain, and
holding the eccentric axle 6 fixed by direct contact without the aid of intermediate
mechanism, and avoiding looseness and rattle by wear as in Collier's invention.
The inclined plane f at the end of the sliding bolt d may be either a single one so
as to only act when the gear is being driven in a forward direction, or it may be
double, as shown, so that the bolt may be withdrawn when the eccentric axle b is
being driven either backwards or forwards.
The invention may be applied either entirely between the ball races of the
eccentric axle b as shown, or it may be at the end outside one of the bull races, but
the advantage of applying the same at the inside as drawn is that it is then enclosed
entirely inside the bottom bracket a, and is protected from dust, and by dispensing
with the projecting end of the eccentric axle the tread or width between the pedals is
reduced without reducing the distance between the ball races.
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 what
I claim is:
First, the improvement in the method of withdrawing the sliding bolt in the
Collier two-speed gear, and secondly, the improved arrangement for holding the
eccentric axle fast when the higher speed is being used, substantially as hereinbefore
described and illustrated by the drawings annexed.
Dated this Sixth day of August 1807
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.