Year: 1886

page_text: I, GUSTAV MELCHER, Manufacturer, of Düsseldorf, in the German Empire, 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 accompanying drawings represent suction- and force-pumps, by which the
fluid in the pressure-pipe is propelled with constant speed. They differ therefore
from pumps, which are actuated by eccentrics or pistons in the usual way, by
delivering a certain quantity of fluid with each angle of rotation of the driving
axle. This uniform motion of the pump-pistons is produced by discs placed
obliquely to their axes or by eccentric discs, which may also be provided with
grooves. The motion of the axle of these discs may be produced by straps, wheels,
worm, ratchet-wheel and pawl etc.
Figs. 1 to 9 show a two-cylinder pump, which is provided with a peculiar conical
or mitre valve 8 situated in the casing 9. From the narrow part of this casing
extends the suction pipe and from the wide part the pressure pipe. Through the
channels b b¹, the cylinders c c¹ are in connection with the valves (Figs. 2 to 5).
In the position indicated by the drawing, the channels b b¹ are closed by the
valve.
By turning the axle w or the valve 8 in the direction of the arrow (Fig. 1) the
slot 8 in the valve is made to appear before the channel b and thus to connect the
cylinder c with the suction chamber. At the same time the slot 811 is placed before
the channel b¹ for connecting the cylinder c with the pressure-chamber, until the
pistons p, which are simultaneously moved by the grooved disc n, have arrived at
the opposite end of their travel, after which they change so that then for the other
half revolution the cylinder c is connected with the pressure chamber and c' with
the suction chamber. The valve is so connected with the shaft w by the coupling k,
that it must take part in the revolution of the said axle. The coupling k is
adjustable in the direction of the shaft, and, to avoid a stuffing box, it is tightened
against the casing g by means of a cone or a ring surface, a spring serving to
press it on.
The disc n, which, partaking of the rotary motion of the shaft w, produces the
to-and-fo motion of the two pistons p p¹, carries at the periphery a continuous
groove, which forms on one half of the periphery, a half turn of a right hand screw,

page_text: and on the other half a half-turn of a left-hand screw, as shown by Figs. 8-10,
Fig. 8 showing the developed centre-line.
In this half right and half left hand helical groove are situated the rollers or
slide blocks, secured to the piston.
Owing to this shape of the groove the travel of the pistons in one or the other
direction has always the same extent, when the disc n is turned for an equal angle.
The disc n may be fixed on the axle w, or it may, as shown by Figs. 2 and 6, be
adapted to turn on a ball or disc for allowing it to be put also into other positions
to the axle and thereby the lift to be adjusted to a certain extent. Figs. 12 to 16
represent a single cylinder pump, to which is applied a helically grooved disc,
the development of which is shown by Fig. 18. Here the grooved disc forms nearly
a whole turn of a screw, the ends of which are connected at i. The helical groove
causes the uniform motion of the piston in the cylinder and forms therefore the
pressure-period, while, by the part i of the groove, the piston is rapidly drawn
back, so that only a short interruption of the pressure takes place. The action of
the valve is effected in a similar manner, as with the pump described above, by the
conical or mitre valve 8 connected with the shaft w. In the position indicated
the piston p is situated at its lowest point, and the channels b 6¹ are closed by the
valve 8. By turning the shaft win the direction of the arrow, Fig. 15, the short
backward motion of the piston commences, during which the channel b is connected
through the slot 81 (Figs. 11 and 12) with the suction chamber, while channel 6¹
(Fig. 13) remains still closed. As soon as the piston p has attained its extreme
position, the slot 81 has passed the channel, and the latter is closed, while now the
circumferential groove 8 of the valve connects the channel with the pressure
chamber. In this pump, the coupling k is tightened by cone and spring, while
Figs. 4, 5, 16 and 17 show another arrangement of the valve 8. The latter is here
so far extended, that it still tightens the wall of the casing g behind the suction
opening, so that a tightening of the coupling is not required. A circumferential
groove in the valve 8 moves, when the latter turns, always in front of the suction
opening and, in Figs. 4 and 5, is connected with the interior of the valve and
therefore with the slot s¹; in Figs. 16 and 17, however, it is directly connected
with the slot 8¹.
In all arrangements of the valve 8, the larger diameter of the same is on that
side, where the pressure chamber is situated, and the smaller diameter on the side
where the suction chamber is situated, by which arrangement an automatic
tightening is obtained. The uniform motion of the pistons may, instead of by
helically grooved discs, also be obtained by spirally grooved discs, as represented
by Figs. 19 to 24. Fig. 22 shows a half-left-hand and half right-hand spiral line.
After this, a cam Fig. 23, may be formed, or a groove in the surface of a disc,
Fig. 24, which move the pistons to and fro by rollers, lying on the periphery or
projecting into the grooves. Fig. 19 shows an almost complete turn of a spiral
with short joining curve at i. After this figure likewise a cam, Fig. 20, may be
formed, or a groove in the surface of a disc, which, as described, move the piston
to and fro by rollers or pulleys. Likewise the disc may be provided with a
projecting rim or edge, embraced by a pair of rollers. All mechanisins, such as
belically grooved discs, may also serve to move disc-pistons instead of plunger
pistons, and the pistons of pumps, which have other valves, slides etc. The pumps
are especially intended as high pressure oil pumps, but may also be employed for
other purposes.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what
I claim, is
1.) The employment of cams, or grooved discs, or discs having projecting rims
on the circumference or face, forming a half turn of a right hand screw or spiral
and a half turn of a left hand screw or spiral in the case of double cylinder pumps,
and an almost complete turn of a screw or spiral with short connecting line in the

page_text: case of single cylinder pumps, in combination with slide blocks or rollers actuated
by said cams or discs and connected with the pump piston in any convenient
manner, said slide blocks or rollers projecting into the grooves or embracing the
projecting rim in pairs or resting on the periphery of the cam, for the purpose of
obtaining a continuous action of the pump.
2.) The attachment of the helically grooved disc to a ball or disc in such a
manner, that the inclination against the axis, and therefore the stroke, can be
altered.
3.) The employment of (truncated cones in suitable casings to serve as valves in
suction- and force-pumps, the said cones being so connected with the driving shaft
for the pump pistons, as to take part in the rotary motion of the same, and provided
with alots or circumferential grooves adapted to connect the pump cylinders
alternately with the suction pipe and with the discharge pipe.
4.) The arrangement of the said valve cones in such a manner, that the wide end
is near the pressure chamber and the narrow end near the suction-chamber, for the
purpose of obtaining an automatic packing.