Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a lubricating appara-
tus, particularly an apparatus able to provide grease
automatically to a location to be lubricated, for example
a bearing, without manual attendance.
Automatic greasing apparatus are well known.
They provide the great virtue of providing a constant
supply of lubricant to a bearing, or indeed anything that
needs to be lubricated, without manual interference.
That is it is not necessary to keep a schedule of what
bearings have been lubricated and what have not and when
the bearings should be lubricated. Th~ automatic appara-
tus simply provides a constant flow of grease.
The principal method of forcing the grease to
the place to be lubricated is by gas pressure. The gas
pressure may be developed by chemical reaction and the
pressure developed, as a result of gas development, is
used to force grease from the container, down a grease
line to the bearing.
The apparatus is reliable and long-lasting.
Indeed apparatus developed by applicant is able to pro-
vide lubrication of a bearing Eor upto 3 years which is
extremely desirable, especially where it can be difficult
for a man to reach to carry out the necessary
lubrication.
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In prior art automatic greasing apparatus it is
usual to incorporate a neoprene or rubber diaphragm. The
gas acts against the diaphragm, stretching it to move a
piston to move grease out of a grease chamber.
However there are a number of disadvantages
with the use of rubber and neoprene diaphragms prin-
cipally because such diaphragms do not react in a uniform
manner to pressure or to temperature. Furthermore their
resistance temperature is not particularly good, espe-
cially the resistance to low temperature. As a result
the characteristics of the diaphragm can change markedly
and this, of course, can have an effect on the lubri-
cating capability of the apparatus.
The present invention seeks to provide a means
of avoiding this inconstant response by providing as part
of the greasing apparatus, used to force grease from the
apparatus, a component that is able to withstand wide
variations in temperature, with a consistent response
and, similarly, wide variations in pressure, again with a
constant response.
~ ccordingly the present invention is in a
lubricating apparatus comprising a lubricant chamber with
an outlet for lubricant in the chamber; a gas generating
device to generate gas to develop pressure; means
responsive to the pressure to force lubricant Erom the
chamber, and is the improvement whereby the means respon-
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sive to the pressure is a bellows.
Aspects of the invention are illustrated,merely by way oi example, in the accompanying drawings in
which:
Figure 1 is a perspective view of a lubricating
apparatus according to the present invention;
Figure 2 is a bottom plan view of the lubri-
cating apparatus of the invention with its base member
removed;
Figure 3 is a section on the line 3-3 in
Figure 2;
Figure 4 is a detail of bellows useful in the
apparatus of the present invention;
Figure 5 is a diagram of a circuit useful in
controlling the apparatus of the present invention;
Figure 6 illustrated a modification of the cir-
cuit of Figure 5;
Figure 7 illustrates a further modification of
the circuit of Figure 5; and
Figure 8 illustrates a simple circuit diagram
using an external power source.
The drawings show a lubricating apparatus
comprising, as shown particularly in Figure 3, lubricant
chamber 2 having an outlet 4 for lubricant. In the
drawing, which is simply of the apparatus, not in its
working position, the outlet 4 is blocked with a plug 6,
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removed when the device is to be used. A grease line can
then be a-ttached on threaded portion 8.
There is a gas generating device to generate
gas to develop pressure. These means are well known and
may, for example, comprise a reaction chamber 10 having
an anode 12 and a cathode 14. Batteries 16 are provided
to provide voltage across the anode 12 and the cathode.
The reaction chamber 10 may contain any chemical com-
position that, upon the application of a voltage, genera-
tes the gas. Typically, for convenience of storage the
reactants are absorbed on a sponge.
There are a plurality of resistors 18 tsee
Figures 4, 5 and 7) between the batteries 16 and the
electrodes 12 and 14. Resistors 18, 20, 22, 24 and 26
are mounted in a printed circuit board (PCB) 28 attached
to base member 30. The printed circuit board has the
resistors 18 to 26 located on it and, of course, com-
municating with the printed, copper circuit. Screws 32
act as switches. One screw 32 is shown extending exter-
nally of the base member 30 so that its head makes a con-
tact for the printed circuit and introduces a resistor
into the circuit. The resistors 18 to 26 are a predeter-
mined value as indicated in Figure 5. Typically the
exterior oE the device, usually the base member 30, will
be marked with an indication of time. That is iE one
resistor 18 to 26 is brought into contact by moving a
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screw 32 so that its head completes the circuit ~see the
left screw in Fi~ure 3) then the device will be useful
for a certain time, aEter which all the grease will have
been expelled from the chamber.
The batteries 16 contact leads 34 and 36 to
supply power to the reaction chamber lO from the ~rinted
circuit board. Conductor member 34 takes the power to
the anode 12. Conductor 36 takes power to a conductor 38
on the printed circuit board 28 to the cathode 14. The
arrangement is conventional, that is the printed circuit
board is entirely conventional and not in any way form a
part of the present invention. Current is conducted to
the reaction chamber 10 through metallic studs 40, insu-
laked from the remainder of the structure by insulating
members 42.
The apparatus includes means responsive to the
pressure generated by the gas to force lubricant from the
chamber. In the present invention the means responsive
to the pressure comprises a bellows 44, as most clearly
shown in Figure 4. The bellows 44 is typically of
polyamide and, in a preferred embodiment is made of the
nylon available under the trade mark PEBAX. The bellows
i5 formed with corrugations 46 enabling its expansion and
contraction. Ik is closed at one end 48 and is formed at
its base with a flange 50.
~ piston 52 is also located in the lubricant
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chamber 2. In the illustrated embodiment - see Figure
3 - the bellows 44 expands on the generation of gas to
push against piston 52 which is a gastight slidable fit
within the chamber 2.
The apparatus includes a collar 54 to which the
lubricant chamber 2 is threadedly attached at 56. The
base member 30 is clamped between the collar 54 and
member 58, which includes the reaction chamber 10 and a
recess 60 to receive the batteries 16. As shown in
Figure 2, member 58 may be formed with bracing ribs 62.
Bellows 44 is then clamped by an internal flanye 6~ on
the lubricant chamber 2 abutting a flat 66 on the
member 58. Flat 66 may be formed with projection 67 to
assist in sealing. O-ring 68 seals base member 30 to
member 58.
To use the device of the present invention it
is clamped in position with thread 8 attached to a grease
line for whatever is desired to be lubricated, typically
a bearing. A screw 32, which of course functions as a
switch, is withdrawn, depending upon the needed time of
operation, as shown to the left in Figure 3 and the cir-
cuit across the reaction chamber thus established.
Lubricant chamber 2 is, of course, full o grease. As
the gas is generated it expands bellows 44 which moves
the piston 52 which Eorces grease Erom the chamber
through outlet 4.
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The bellows 44 has a great number of advantages
over the prior art but in particular has the great virtue
of consistency of performance. That is regardless of
external pressure or temperature the bellows, as
illustrated in Figure 4 according to the preferred embo-
diment of the invention, provides particularly uniform
performance. In the prior art bellows would not, of
course, be present but neoprene and rubber devices have
been used, typically in the form of a diaphragm. ~lowever
the stretch curve of such a diaphragm varies markedly.
That is its elastic properties diE~er markedly depending
upon the external pressure and the amount of stretching
that it has undergone. Furthermore rubber and neoprene
have less desirable temperature responsive charac-
teristics. Rubber at relatively cold temperatures
requires much ~reater pressures to stretch it and at low
temperatures, Eor example minus 40C, can re~uire such
pressure to stretch that it will not be effective in the
lubricating apparatus of the type according to the pre-
sent invention.
The nylon bellows will not become brittle until
minus 94C but rubber becomes brittle at about minus
64C.
Various circuits useEul with the apparatus o-E
the present invention and, in particular, built into the
printed circuit board 28 on the base member 30 of the
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apparatus are illustrated in Figures 5, 6, 7 and 8. The
circuit of Figure 5 is most simple and comprises a 3 volt
power source, typically two ~A batteries 16, mounted
within the recess 60. ~ light emitting diode LED 70 is
arranged in series with resistor 72 and with
transistor 74. A second transistor 76 is in series with
the first and emitter 78 communicates with line 80.
Resistors 82, 84 and 86 are positioned in
series with a third transistor 88. The electrochemical
reactor 10 is arranged as shown particularly in Figure 3
and power supply to the reactor 10 is controlled by
resistors 18 to 26, each controlled bv switches 32. The
arrangement is such that current is applied to the
electrochemical reactor and, depending on the number of
switches 32 that are closed, the period of reaction
within the reactor, and thus of gas generation, is
controlled. The LED 70 indicates when current flows in
the circuit, that is when the device is in operation.
Figure 6 differs from Figure 5 only by the pro-
vision of a pressure sensing device 90 to vary the
current in the circuit depending on ambient pressure.
The sensing of ambient pressure permits the operation of
a shunt 92 to vary the current to the electrochemical
reactor 10 and thus the supply oE lubricant. If the
external pressure increases then the generated pressure,
that is the volume of gas generated, should be increased.
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Figure 7 illustrates a more complicated
variation of the circuits o~ Figures 5 and 6. It differs
from those circuits by the fact that pressure sensing
device 90 is able to shunt any selected timing circuit.
In Figure 7 the time for which the device is operable
with the numbers of resistors 18 to 26 switched into the
circuit is shown.
The circuit again has a current source 16,
typically in the form of A~ batteries joined in series~
across the electrochemicaL reactor. Resistance 94 is in
series with the reactor 10. The circuit has
transistor 96 shunted by line 98 containing resistor lO0
and transistor 102. Transistor 102 is in series with
capacitor 104. An LED 106 is present with resistor 108
in parallel and resistor 110 in series. Capacitor 112 is
in series with resistor 110. Transistor 114 is in series
with resistor 116 and with transistor 118. Resistor 120
is the equivalent of resistor 84 in the circuit of
Figure 6. Transistor 118 is in series with resistor 122.
The circuit shown in Figure 8 is a simple indi-
cation of the use of an external source 124 feeding
through a transformer to provide power to the circuit.
The external source 124 may, for example, be a battery oE
a vehicle, especially where the lubricating apparatus is
mounted on a vehicle. The circuit includes sockets 126,
resistor 128 and switch 130, typically mounted con-
veniently, for example on the facia oE a vehicle.
