Year: 1895

page_text: 1, PAUL GIFFARD, of 7 Rue Delaborde, Paris, in the Republic of France do
hereby declare the nature of this invention to be as follows:-
This invention relates to pumps, for various purposes, but I will describe them
as suitable for pumping air or gas.
In carrying out the invention any suitable form or size of cylinder is employed
in which is a moving piston arranged in the following manner;-
The piston which may be a loose fit in the cylinder is provided with a peripheral
recess in the usual manner, and in this is fitted a ring of any suitable material, say
india-rubber, preferably adapted to maintain a moderate working contact between
its periphery and the interior of the cylinder. This ring is made so as not to
closely fit the sides of the groove or peripheral recess in the piston, the object
being that when the piston reverses its stroke the ring will alternately engage with,
and be free from, the walls of the peripheral recess in the piston. In one face of the
piston perforations or equivalent are made from the face to the interior of the
groove in the piston, so that the packing ring will operate also as a valve making
alternately, according to the direction of movement of the piston, contact with one
or other of the faces. Thus, when the contact is made with the perforated face,
the air or other fluid upon which the pump is operating will pass through the
openings or perforations in that face of the piston and pass between the interior of
the packing ring and the piston, and escape between the piston and the cylinder
beyond the packing ring, thus travelling freely through the piston as though an
open valve were provided therein. Upon the return stroke, the packing ring will-
engage with the opposite face of the piston groove thus preventing the passage of
the fluid through the piston and operating as a closed valve. Consequently when
moving in one direction, the piston operates as an open valve, and when moving
in the other direction, it operates as a tight-fitting closed piston to force the
fluid.
Any suitable non-return valve may be employed preferably at the end of the
cylinder opposite to that through which, the piston rod passes and this may be
covered in by a cap provided with a screwed nipple to engage with a corresponding
socket upon the tube or vessel into which the fluid is to be discharged, or the
nipple may have rings upon it or be roughened to receive a rubber or other
flexible tube.
Any suitable materials may be employed in the construction of this pump, or its
parts; the cylinder may be made of metal-steel, copper or aluminium, for
example-or of other material, say ebonite, rubber, paper, or other equivalent and
suitable material. The valves may be made of the same materials, but it is found
that rubber gives good results.
!.
The end of the pump cylinder, remote from the valve, may be closed-in by any
convenient cap or equivalent, and the piston may be operated by a rod or tube
provided if necessary with a head or handle outside; the pump as described would
be a single-acting pump, but the parts may be modified or duplicated as required,
to make it a double-acting dump.

page_text: These punips may be made in large size for shop use for charging tyres and may
be provided with branches for the tyre and for the pressure gauge.
Dated this 23rd day of April 1895.
BOULT & WADE,
Agents for the Applicant.
I, PAUL GIFFARD of 7 Rue Delaborde, Paris, in the Republic of France do
hereby declure 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 invention relates to pumps, for various purposes, but I will describe them
as suitable for pumping air or gas.
The invention will be best understood by reference to the accompanying
drawings which show the pump in longitudinal section, Fig. 1 showing it as when
the piston is being raised and Fig. 2 as when the piston is being lowered.
In carrying out the invention any suitable form or size of cylinder A is
employed in which is a moving piston arranged in the following manner;
The piston B which may be a loose fit in the cylinder A is provided with a
peripheral recess B' in the usual manner, and in this is fitted a ring C of any
suitable material, say india-rubber, preferably adapted to maintain a moderate
working contact between its periphery and the interior of the cylinder A. This
ring is made so as not to closely fit the sides of the groove or peripheral recess B¹
in the piston B the object being that when the piston reverses its stroke the ring
will alternately engage with, and be free from, the wails B2 B3 (Figs. 1 and 2)
of the peripheral recess. In one face of the piston perforations or equivalent B4
are made extending from the face to the interior of the groove B¹, so that the
packing ring C will operate also as a valve making, alternately, according to the
direction of movement of the piston, contact with one or other of the walls B2 B3.
Thus, when the contact is made with the perforated wall B3 B4 as in Fig. 1, the
air or other fluid upon which the pump is operating will pass through the openings
or perforations B4 and pass between the interior of the packing ring C and the
piston B; and escape between the piston B and the cylinder A beyond the packing
ring C, thus travelling freely through the piston as though an open valve were
provided therein. Upon the return stroke as shown in Fig. 2 the packing ring C
will engage with the opposite face B2 of the piston groove B¹ thus preventing
the passage of the fluid through the piston and operating as a closed valve.
Consequently when moving in one direction as in Fig. 1, the piston operates as an
open valve, and when moving in the other direction as in Fig. 2, it operates as a
tight-fitting closed piston to force the fluid.
The before-described ring C fulfils the functions of both the piston-packing and
valve.:
Any suitable non-return valve D may be employed preferably at the end of the
cylinder opposite to that through which the piston rod E passes and this may be
covered in by a cap or equivalent F provided with a screw nipple to engage with a
corresponding socket upon the tube or vessel into which the fluid is to be
discharged, or as shown in the drawings the nipple F1 may have rings upon it or
be roughened to receive a rubber or other flexible tube G.
Any suitable materials may be employed in the construction of this pump, or its
parts; the cylinder may be made of metal steel, copper or aluminium, for
example-or of other material, say ebonite, rubber; paper; or other equivalent and

page_text: suitable material. The valves may be made of the same materials, but it is found
that rubber gives good results.
The end of the pump cylinder A. remote from the valve may be closed in by any
convenient cap or equivalent A¹ and the piston rod E which may be solid or
tubular if necessary is provided with a head or handle E' outside; the pump as
described would be a single-acting pump, but the parts may be modified or
duplicated as required, to make it a double-acting pump.
These pumps may be made in large size for shop use for charging tyres and may
be provided with branches for the tyre and for the pressure gauge.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what I
claim is ;-
1. The combination with a pump piston of a ring which acts both as piston-
packing and valve.
2. In a pump the combination with a recessed piston such as B B' having
openings extending from one face of the piston into the recess of a ring or valve
such as C capable of alternately making contact with the two sides of the recess
substantially as described and illustrated in the accompanying drawings.
3. The combination and arrangement of parts constituting a complete pump:
piston substantially as described and illustrated in the accompanying drawings.
Dated this 24th day of February 1896.
BOULT & WADE,
Agents for the Applicant.