Improved Apparatus for the Manufacture of Cycle Gear Cases.
Year: 1896

page_text: Date of Application, 21st Aug., 1896
PROVISIONAL SPECIFICATION.
Improved Apparatus for the Manufacture of Cycle Gear Cases.
We. HORACE WALTER DOVER, Engineer, and PICKERING PHIPPS, Gentleman,
both of The Dorman Engineering Company, Mayorhold, Northampton, do hereby
declare the nature of this invention to be as follows: -
This Juvention relates to tools for moulding gear cases of xylonite, celluloid
and the like for bicycles (of the kind known as the Dover Gear Case made in halves
divided longitudinally at the plane of the crank and driving wheel axles) and the
Invention comprises preparatory tools for bringing the material in the sheet roughly
to the form of the case and finishing tools for bringing the roughly moulded case
to its final formn.
The preparatory tools comprise a lever or screw operated plunger or "form"
preferably made of wood and of a shape conforming roughly to that of the interior
of one half of the case, an apertured die plate through which the material is drawn
by the pressure of the "former," a presser plute which in conjunction with tho
die plate is provided with special means of smoothing out the wrinkles or puckers
formed in the marginal portions of the material in consequence of the drawing
action through the die plates, and means of applying the necessary pressure
thereto.
To prevent the puckers of the marginal portion of the sheet extending into the
moulded article the aperture in the die plate is surrounded by a raised rib of half
round section forming a rounded edge over which the material may be drawn
easily without tearing and the pressure plate is provided with a similarly shaped
rib opposed in direction to, and lying outside of or surrounding, the rib on the
die plate so that the sheet in passing first under the one rib and then over the other
will be deflected from its plane the ribs acting on opposite sides of the sheet
in such manner as to gently smooth out or keep back the wrinkles whilst the
material is being drawn through the die. The presser plate is held down upon the
sheet by spring hooks pivoted universally in brackets below the die plate so tha
the hooks may be swung aside and turned down out of the way when out of use.
The tool for pressing the article (after being roughly moulded as above
described or otherwise) to its final form comprises a male die and a female die or
matrix respectively corresponding to the internal and external orm of the case, the
male die being actuated by pressure screws mounted in stirrup brackets pivoted
to the framing of the female die and the female die being formed of a middle
member or bottom bar corresponding to the shape of the rounded bottom and ends
of the moulded article and of two cheek plates forming the opposite sides of the
mould pivoted loosely at either side of the middle member so as to swing outwards
to release the moulded article these cheek plates being drawn together by lever
arms pivoted universally to the middle member and acting on the cheek plates
through thrust pins, the long arms of the levers being drawn together to apply
the pressure necessary to close the cheeks against the central member by connect-
ing stirrups and pressure screws. The male die is made hollow and strengthened

page_text: by transverse divisions or distance pieces and is provided with a detachable offset
at one side which may be changed to vary the form of the case to suit particular
requirements, the corresponding part of the cheek plate being changed also.
In conjunction with this mould there is used a plate apertured to correspond to
the shape of the mould and which rests on the top of the mould and supports the
marginal flange of the partly moulded article, and also a pressing plate which
rests on the marginal flange and serves by its weight to retain the flange in place
during the additional drawing which the partially moulded material undergoes
when the die is forced home into the matrix in order to complete the moulded
article. The mould is made of inoxidisable alloy and the moulding operations
are performed by immersion in boiling water.
Datad this 21st day of August 1896
A. M. & WM. OLARK,
53, Chancery Lane, London, Chartered Patent Agents.
COMPLETE SPECIFICATION.
Improved Apparatus for the Manufacture of Cycle Gear Cases.
We, HORACE WALTER DOVER, Engineer, and PICKERING PHIrrs, Gentleman,
both of The Dorman Engineering Company, Mayorhold, Northampton, 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: -
This Juvention relates to tools for moulding cycle gear cases of xylonite (of the
kind known as the Dover Gear ('ase) and the Invention comprises a preparatory
tcol for tringing the material in the sheet roughly to shape and a finishing tool
for bringing the roughly moulded article to its final form. The gear case is made
in halves divided longitudinally at the plane of the crank and driving wheel axles
of the machine and as the two halves differ somewhat in shape a set of preparatory
and finishing tools would be provided for each although the same preparatory tool
might be used for both halves if desired.
Reference is to be had to the accompanying drawings forming part of this
Specification wherein Figure 1 is an elevation, Figuro 2 a plan, and Figure 3 a
transverse section, on line 33 Figures 1 and 2, of the first or preparatory tool.
Figures 3 and 3* are longitudinal and cross sections of the partially moulded half
case as it leaves the preparatory tool. Figure 4 is an elevation Figure 5 a plan,
Figure 6 an end elevation, and Figuro 7 a cross section of the finishing tool, the
latter figure shewing the matrix in the opened position. The same letters of
reference indicate the same parts in all the figures.
The preparatory tool comprises a male dio or "former" A preferably made of
word and of a shape conforming roughly to that of the interior of the half case the
"former" being suitably guided in uprights B and pressed upon by a hand lever C.
It further comprises an apertured die plate 1) or table upon which the sheet of
material is laid in order that it may be forced or drawn by the pressure of the
"former" through the aperture of the die plate which corresponds in configura-
tion thereto with just sufficient clearance to allow for the material. In order to
smooth out the radially extending wrinkles or puckers that form in the marginal
portions of the material in consequence of the contraction caused by drawing the
central portion of the material through the aperture of the die plate and so to
prevent the puckers of the marginal portion of the sheet extending into the
imoulded article, the aperture in the die plate is surrounded by a rib d of half round
section on the upper surface of the die plate forming a rounded edge over which
the material may be drawn easily without tearing and the sheet of material is
pressed between the die plate or table D and a pressure plate E provided with a

page_text: similarly shaped rib e opposed in direction to, and surrounding the rib d or situated
at the side thereof farthest from the aperture of the die plate so that the sheet of
material in vielding to the pressure of the male die or "former" A forcing it
through the die plate will be drawn between the pressure plate E and the die plate D
passing first under the rib e and then over the rib d whereby the said ribs will
be caused to exert a scraping action on opposite sides of the sheet in such manner
as to gently smooth out and keep back the wrinkles. The pressure plate E is held
down upon the sheet by a pair of spring hooks whose shanks are pivoted to turn
about their vertical axis in brackets G which are in turn pivoted on horizontal
axes g in brackets H fixed below the die plate so that the hooks may be swung
aside and turned down out of the way when out of use. Springs f coiled about
the shanks of the hooks apply the necessary yielding pressure to the middle of the
plate at opposite sides and in order to distribute this pressure uniformly over the
plate E the latter may be slightly cambered in the direction of its length.
The operation of moulding is performed by laying the sheet of xylonite, out to
a shape conforming approximately to that of the pressure plate, between the die
plate or table and the pressure plate, applying the spring pressure hooks, and
immersing the whole in hot water at the proper temperature to soften the xylonite,
and then gently forcing it by the pressure of the lever operated die or "former"
through the aperture of the die plate, care being taken to avoid tearing the
material by excessive ressure of the "former" whilst maintaining sufficient
pressure between the table and presser plate to prevent wrinkles extending into the
mouldeu article.
The tool for pressing the article (after the latter has been roughly moulded as
above described or otherwise) to its final form (see Figures 4 to 7) comprises a male
die or plunger I and a female die or matrix respectively corresponding to the
internal and external final form of the half case, the male die being actuated by
presser screws J mounted in stirrup brackets K pivoted at k to the framing of the
female die and the female die being formed of a middle member or bottom bar L
having uprising ends and corresponding on the inner face to the shape of the
rounded bottom and ends of the moulded article, and of two cheek plates M M
forming the two sides of the mould. The cheek plates M are pivoted loosely at
either side of the middle member L by means of tangs m apertured to rest swing
and slide upon pins m¹ projecting from the middle member L so that the cheek
plates M may be swung outwards, as shewn in Figure 7, in order to enable the
plunger I to be for.ed down home upon the middle member L and to permit of its
release when the operation is terminated. These cheek plate. M are closed against
the middle member L by pairs of levers N each of which is pivoted universally to
the middle member by two axes n n (whereof one, riz:-n, may consist of a pro-
lengation of pin k) at right angles and these levers act on the cheek plates through
trust pins the extremities of the levers of each pair being drawn together to
epply the pressure necessary to close the cheeks against the central member by a
screw oupling formed by a stirrup Q pivoted to the one lever of the pair and a
Fiessure sew 9 serewing through a nut in the end of the stirrup and bearing
agains: the other lever of the pair. The male die or plunger I is made hollow and
strengthened by transverse ribs and it is provided with a detachable offset I¹ bolted
to it at our side which may be changed to vary the form of the die to suit particular
requirements, the corresponding part of the adjacent cheek plate being made
detachable so that it may be changed also.
In conjunction with this mould there is used a die plate It apertured to cor-
respond to the shape of the mouth of the mould and which tests on the up-turned
ends of the middle member of the mould to which it is fitted by steady pins r.
This die plate is slipped over the partially moulded article when the latter is placed
upon the male die T which is removable from the press for the purpose. It serves
to clip the partially moulded article upon the die I when the whole is placed as one
in the press, the plate R when in position therein serving to support the marginal
flange of the partly moulded article. A pressing plate S rests as a dead weight

page_text: on the marginal flange and serves to retain the flange in place during the
additional drawing which the material undergoes when the die or plunger I is
forced home. After this has been done the cheek plates M are closed in by means
of the levers N and sorew couplings in order to close the mould and complete the
moulded article.
The operations of forcing the plunger home and closing in the sides of the matrix
are performed with the aid of heat preferably whilst the tool is immersed in water
at the proper temperature to soften the material, and when the operation is com-
plete the material is caused to set in the moulded form by cooling of the mould,
preferably by immersion in cold water. After the operation is completed, the
marginal portions of the moulded article are trimmed off.
The die or plunger I and the members L and M of the matrix are preferably
made of gun-metal, the whole of the tool being made of the same or of other
inoxidizable alloy.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed we declare that what
we claim is:-
1. A tool for the preparatory moulding of sheet xylonite, celluloid, or like
material, roughly to the form of a gear case, consisting in the combination of a male
die or "former" an apertured die plate and a presser plate the adjacent faces of the
die plate and presser plate having oppositely projecting ribs surrounding the die
aperture of the rib on the one plate surrounding the rib on the other plate so as to
successively act on opposite sides of the material, as scrapers extending entirely
around the die aperture whereby to smooth out wrinkles from the material drawn
between them substantially as specified.
2. In a tool for the preparatory moulding of sheet xylonite, celluloid, or like
material the combination, with a frame, of a die plate, a male die or "former"
carried by the frame and movable through the die plate, a pressure plate bearing
down on the die plate the pressure and die plates having oppositely projecting ribs
adjacent to each other, and means for holding the pressure plate down on the
die plate substantially as described.
3. In a tool for the preparatory moulding of sheet xylonite, celluloid, or like
material the combination, with a frame, of a die plate having an orifice, a mule die
or "former" mounted on the frame to move vertically through the orifice of the
die plate, a pressure plate, and means for holding the pressure plate in position
substantially as described.
4. In a tool for the preparatory moulding of sheet xylonite, celluloid, or like
material the combination, with a frame, of a die plate carried by the frame and
having an orifice, a pressure plate located above and bearing on the die plate and
having upwardly extended channelled guides, a male die or "former' slidable
vertically in the guides, and means for holding the pressure plate down upon
the die plate substantially as described.
6. The combination, with the frame, the orificed die plate carried thereon, and
the orificed pressure plate, the die plate and presser plate having ribs adapted to
act as scrapers on opposite sides of the sheet of plastic material drawn between
them by the action of a die, of spring-pressed hooks carried by the frame and
vieldingly holding the presser plate in position, the hooks being pivoted to turn
about their axes in brackets pivoted on transverse axes below the die plate
substantially as described.
6. The combination, with the die and presser plates having ribs adapted to act
as scrapers on opposite sides of the sheet of plastic material drawn between them,
and with means co-acting with the die and presser plates to mould the plastic
material, of a bracket pivotally mounted at each side of the presser and die plates
and a spring-pressed hook carried in each bracket and yieldingly holding the
pressure plate in position substantially as described.

page_text: 7. A finishing tool for moulding xylonite, celluloid, or 'he like material, con-
sisting of the combination of a male die or "former," a matrix formed of a middle
member enclosing the bottom and ends and of two loosely-pivoted side members,
and means for forcing and holding the die in the matrix and for closing the sides
of the matrix upon the article on the die substantially as specified.
8. In a tool for moulding xylonite, celluloid, or the like material, the combina-
tion of a screw-operated male die or "former," a matrix formed of a middle
member and of two loosely-pivoted side members, and of levers and screw-operated
connecting links for closing the sides of the matrix upon the article on the die
substantially as specified.
9. In a tool for moulding xylonite, celluloid, or the like material, the combina-
tion of a screw-operated male die or plunger, a matrix formed of a middle member
and of two loosely pivoted side members closed by levers and screw couplings
against the article on the die, and of a die plate to support the unmoulded marginal
flange of the article, and a presser plate to hold the Hauge own on the die plate
substantially as specified.
100%
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agente.