An Improvement in the Manufacture of Blocks of India Rubber.
Year: 1890

page_text: Date of Application, 15th Aug., 1890
Complete Specification Left, 11th May, 1891-Accepted, 20th June, 1891
PROVISIONAL SPECIFICATION.
An Improvement in the Manufacture of Blocks of India Rubber.
We CHARLES MACINTOSH AND COMPANY LIMITED of Cambridge Street
Manchester in the County of Lancaster India Rubber Manufacturers and Joux
BAGNALL of the same place Manager do hereby declare the nature of this
invention to be as follows:-
Solid blocks of india rubber from which sheets of rubber are cut, are now
usually formed by the rubber being placed in a soft or plastic state in a hydraulic
The
press and afterwards subjected to a great pressure to solidify the same.
cylindrical block is then taken from the press or cylinder and placed in the cutting
machine whereby it is cut into thin sheets by the reciprocating cutting knife as the
roll slowly revolves.
It is frequently found that there are numerous small holes or perforations in
these sheets which cause a great deal of waste inasmuch as these damaged parts
have in some cases to be cut away altogether.
These holes are caused by small air globules which are formed or imprisoned
in the rubber in process of manufacture and which cannot be removed even by the
great pressure of the hydraulic ram.
This invention is intended to remedy this defect and consists in forming a
vacuum in the hydraulic cylinder after the india rubber has been placed therein in
its soft or pasty state.
This can be effected by a suitable arrangement of pipes and fittings placed on
the top or other suitable part of the ram hox and connected with an exhaust pump
by suitable tubes.
After the air has been exhausted from the cylinder containing the india rubber
the hydraulic ram is set in motion which has the effect of solidifying the mass of
rubber to the requisite density when it will be found that all air has been removed
therefrom and hence more perfect sheets of india rubber will be produced in the
cutting machine as there will be no holes or imperfections caused by the presence
of bubbles of air in the compressed mass as heretofore.
Dated this 14th day of Auơust 1890.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.
COMPLETE SPECIFICATION.
An Improvement in the Manufacture of Blocks of India Rubber.
We CHARLES MACINTOSH AND COMPANY LIMITED of Cambridge Street
Manchester in the County of Lancaster India Rubber Manufacturers and JOHN
BAGNALL of the same place Mauager 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 :-
The
Solid blocks of india-rubber from which sheets of rubber are cut are now
usually formed by the rubber being placed in a soft and plastic in a hydraulic
press and afterwards subjected to a great pressure to solidify the same.
cylindrical block is then taken from the press or cylinder and placed in the cutting
machine whereby it is cut into thin sheets by the reciprocating cutting knife as
the roll slowly revolves.
It is frequently found that there are numerous small holes or perforations in

page_text: these sheets which cause a great deal of waste inasmuch as these damaged parts
have in some cases to be cut away altogether.
These holes are caused by small air globules which are formed or imprisoned in
the rubber in process of manufacture and which cannot be removed even by the
great pressure of the hydraulic ram.
This invention is intended to remedy this defect and consists in forming a
vacuum in the hydraulic cylinder or ram box after the india rubber has been placed
therein in its soft or pasty state.
This can be effected by a suitable arrangement of pipes and fittings placed on
the top or other suitable part of the ram box and connected with an exhaust pump
by suitable tubes, as illustrated by the annexed drawing which is a section of the
upper part of a ram box provided with the necessary fittings.
u is the ram box and the cover of the same which for the purpose of our
invention must be fitted on and made air tight at band by india rubber rings
or otherwise.
Through this cover we drill or form a passage which we connect with the
suction pump or other exhausting device by a pipe d fitted with stop taps e and a
vacuum gauge f
After the air has been exhausted from the cylinder or ram box a containing the
india rubber the hydraulic ram is set in motion which has the effect of solidifying
the mass of rubber to the requisite density when it will be found that all air has
been removed therefrom and hence more perfect sheets of india rubber will be
produced in the cutting machine as there will be no holes or imperfections caused
by the presence of bubbles of air in the compressed mass as heretofore.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
:-
The improvement in the manufacture of blocks of india rubber consisting in
forming a vacuumn in the hydraulic cylinder or ram box after the india rubber has
been placed therein in its soft or pasty state, and previously to, or during, the
compression thereof by the hydraulic ram.
Dated this 9th day of May 1891.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.