Field of the Invention

[0001] The present concept relates to automatic greasing systems and in particular relates to an automatic multi point greasing system which provides pressurized grease to the inlet of one or more grease pumps which deliver grease to multiple grease points.

Background of the Invention

[0002] Automated greasing systems are used to automatically grease at predetermined intervals multiple greasing points on for example heavy off road machinery, and on road tractor and trailers. Automated greasing systems may use one or more electric piston pumps, electric gear pumps, and air or hydraulic operated piston pumps to deliver grease to metering blocks and or directly to a grease point which may be a ball joint for example. Each of these grease pumps will have a pump inlet for delivery of grease into a pump cylinder. In colder climate areas the difficulty encountered with automated greasing systems is that as the temperature lowers the viscosity of the grease increases creating an increasingly greater resistance to flow and therefore an increasing resistance to filling of the pump cylinder when the pump inlet is open. Just prior to the opening of the pump inlet the grease is essentially sitting at a standstill and needs to accelerate and flow to fill the grease pump cylinder. The increased resistance to flow caused by decreasing temperature and corresponding increase in viscosity of the grease limits the output of a particular pump due to slow inefficient and at times totally ineffective filling of the pump cylinder.

[0003] For example an electric pump running at 20 rpm the grease chamber needs to be filled full of grease in approximately 1.5 seconds since the design of the cam lobe usually closes the inlet port at 50% of each cam rotation.

[0004] Current greasing systems rely on atmospheric pressure and the gravity pressure head on the grease to deliver the grease to the inlet port and to accelerate the grease to fill the cylinder. With decreasing temperatures resulting in increased viscosity the flow of the grease becomes sluggish and the amount of grease delivered to the pump cylinder decreases up to a point where the pump becomes non-functional.

[0005] Traditionally this problem is solved by using thinner grade grease or it is decided not to use automated lubrication. Therefore there is a need for compensating for the increased viscosity of greases in automated grease delivery systems with decreasing temperature to ensure that an adequate amount of grease is delivered to the pump cylinder to ensure adequate flow of grease to each of the grease points. Summary of the Invention

[0006] The present concept a pressurized inlet grease delivery system comprising: a) a grease reservoir for housing grease and delivering the grease to a pump inlet of a grease pump;

b) the grease pump for operably delivering grease to a grease point;

c) a means for pressurizing the grease in the grease reservoir such that grease is delivered under pressure to the pump inlet.

[0007] Preferably wherein the grease reservoir is a cylindrically walled chamber including a follower plate separating the chamber into an air side and a grease side.

[0008] Preferably wherein the pressurizing means including a biasing means for applying force onto the air side of the follower plate thereby urging the follower plate into the grease side to pressurize the grease.

[0009] Preferably wherein the biasing means includes a compression coil spring biased against the air side of the follower plate.

[00010] Preferably wherein the biasing means further includes a guide pin with an upper stop wherein the compression coil spring is biased against the upper stop at one end and against the air side of the follower plate at the other end. [00011 ] Preferably further including a means for compressing the coil spring such that the pressure imparted by the coil spring onto the follower plate is relieved.

[00012] Preferably wherein the compressing means includes a lift mechanism which includes; a) a lift rod passing through a reservoir lid; b) the lift rod operably attached at a lower end to the coil spring at the upper end to an advancing mechanism for urging the rod upwardly thereby compressing the spring.

[00013] Preferably wherein the coil spring including lift rings permanently attached to the coil spring the lift rings for engaging with the lower end of the lift rod.

[00014] Preferably wherein the lower end of the lift rod including a rod hook for engaging with the lift ring.

[00015] Preferably wherein the advancing mechanism including a rack and an advancing tooth for urging upwardly the lift rod. [00016] Preferably wherein the compressing means includes a pull mechanism which includes; a) a lift rod passing through a reservoir lid; b) the lift rod operably attached at a lower end to the coil spring at the threaded portion upper end to a nut, such that when the rod is manually rotated it urges the rod upwardly thereby compressing the spring.

[00017] Preferably wherein the coil spring including lift rings permanently attached to the coil spring the lift rings for engaging with the lower end of the lift rod.

[00018] Preferably wherein the lower end of the lift rod including a rod hook for engaging with the lift ring.

[00019] Preferably wherein the grease is pressurized to between 0.3 and 6 psi.

Brief Description of the Drawings

[00020] The current concept will be described by way of example only with reference to the following drawings in which: [00021] Figure 1 is a schematic top plan view of a prior art grease reservoir.

[00022] Figure 2 is a schematic cross sectional view of a prior art grease reservoir.

[00023] Figure 3 is a schematic top plan view of the present concept of a grease reservoir.

[00024] Figure 4 is a schematic cross sectional view of the present concept a grease reservoir shown in a lower position.

[00025] Figure 5 is a schematic top plan view of the present concept a grease reservoir shown in an upper position.

[00026] Figure 6 is a schematic cross sectional view of the present concept a grease reservoir shown in an upper position.

[00027] Figure 7 is a schematic exploded view of some of the main components of the grease reservoir shown in Figure 4. [00028] Figure 8 is a schematic top plan view of a guide pin together with the cross pin.

[00029] Figure 9 is a schematic cross sectional elevational view of the guide pin together with the cross pin.

[00030] Figure 10 is a cross sectional schematic view of a grease pump typically used in automatic greasing systems shown in the inlet open position.

[00031 ] Figure 11 is a cross sectional schematic view of a grease pump typically used in automatic greasing systems shown in the inlet closed position.

[00032] Figure 12 is a schematic flow diagram showing a grease reservoir communicating grease to a grease pump which in turn communicates grease to a ball joint.

[00033] Figure 13 is a schematic top plan view of an alternate embodiment of a grease reservoir showing lift line apertures. [00034] Figure 14 is a schematic side cross sectional view of an alternate embodiment of a grease reservoir shown together with lift line and lift rings.

[00035] Figure 15 is a schematic side cross sectional view of an alternate embodiment of the grease reservoir as shown together with an advancing mechanism and a pull mechanism.

Detailed Description of the Preferred Embodiments

[00036] Figures 1 and 2 depicts a prior art grease reservoir which is currently used in automated greasing systems.

[00037] Grease reservoir 100 includes the following major components namely cylindrical glass walls 102, a lid 104, a base 106, a follower plate 108 which moves up and down along a guide pin 112.

[00038] Follower plate 108 normally includes seals 110 which move slideably along the inner portion of glass walls 102 and guide pin 1 12 normally includes an overflow conduit 1 14. [00039] Grease is normally forcibly injected into grease compartment 250 through a conduit not shown in Figure 2 on the grease side 252 of follower plate 108. Follower plate 108 moves upwardly along guide pin 112 as more and more grease enters into grease compartment 250 and air on air side 254 escapes out of grease reservoir 100. Grease which is housed within grease compartment 250 is delivered out of grease reservoir 100 under gravity pressure head to a grease pump. Additionally the grease pump may create some suction or vacuum on the inlet side of the grease pump thereby assisting the flow of grease from the grease reservoir to the grease pump. Some prior art devices also include a grease agitator at the grease downwardly and out of the grease reservoir.

[00040] Referring now to Figures 3 and 4 Figure 4 is a schematic cross sectional view of the present concept namely grease reservoir 200 which includes the flowing major components namely; glass wall 202, a lid 204, a base 206, a follower plate 208 having seals 210 which slide along glass wall 202. Follower plate 208 is guided by guide pin 212 which is centrally located within grease reservoir 200. Guide pin 212 includes a centrally located overflow conduit 214 communicating with an overflow orifice 228 and the overflow release port 232. [00041 ] Additionally there is a compression spring 222 which is shown in an extended position 234 when follower plate 208 is in the lower position 230. Additionally not shown in the drawings a grease agitator or stirrer may be used at the grease exit for further urging the grease downwardly and out of the grease reservoir. These grease agitators are well known in the art.

[00042] Follower plate 208 divides the grease reservoir 200 into an air side 254 and a grease side 252 which houses grease 220 within a grease compartment 251.

[00043] Compression spring 222 is held in place at the upper end by stop washer 224 which is prevented from moving upwardly by cross pin 226.

[00044] Referring now to Figures 5 and 6, Figure 6 in particular is a schematic cross sectional view of the grease reservoir 200 shown in upper position 240 wherein spring 222 is shown in a compressed position 244.

[00045] Follower plate 208 extends beyond overflow orifice 228 exposing overflow orifice 228 to the grease side 252 of grease compartment 251 such that grease 220 can flow freely through overflow orifice 228 and down overflow conduit 212 and out through overflow release port 232 indicating to the user that the grease reservoir 200 has reached its maximum capacity. When grease reservoir 200 is full not only will the excess grease escape out through overflow conduit 214 and out through overflow release port 232 but also follower plate 208 will make contact with upper stop 216 thereby preventing further compression of spring 222.

[00046] The reader will note that there is downward pressure applied by compression spring 222 onto follower plate 208 as follower plate 208. The spring compression is eased as the follower plate moves from the upper position 240 to the lower position 230 releasing grease out through reservoir outlet 262 which is shown in Figure 12.

[00047] Figure 7 shows in schematic exploded view the components of grease reservoir 200 namely glass wall 202, lid 204 having a cap 250 and O-ring 252 and a screw 254. Grease reservoir 200 further includes an upper seal 256 and a lower seal 258 for ensuring a grease tight seal between glass wall 202 and lid 204 and base 206.

[00048] Figure 7 additionally shows the components used in the present concept namely guide pin 212 having a stop washer 224 and a cross pin 226. Wherein stop washer 224 abuts across the top of spring 222 and the bottom of spring 222 abuts against follower plate 208. [00049] Figure 8 and 9 shows in cross section guide pin 212 including the grease stop 260 which prevents grease from urging out of the top of guide pin but rather forces it down through overflow conduit 214. .

[00050] Figures 10 and 11 show a grease pump 270 in schematic fashion which includes a piston 274, a pump inlet 272, a cylinder 275, a pump housing 278 which includes a check valve 279 and a pump outlet 280. Piston 274 in this particular example includes integrally a cam follower 276 which makes contact with cam 277. Other types of grease pumps may also be utilized such as gear style pumps and other pumps known and used in the art.

[00051] In Figure 10 grease pump 270 is shown in the inlet open position which is the position in which grease can enter freely into cylinder 275 as shown by grease flow arrows 221.

[00052] In figure 1 1 grease pump 270 is shown in the inlet closed position 290 at which time piston 274 urges any grease that has entered into cylinder 275 out through pump outlet 280 and out to the device that will be greased. Grease pump 270 also includes a check valve 279 preventing backflow of grease back into cylinder 275. [00053] Figure 12 is a schematic representation of the pressurized inlet grease delivery system which includes a grease reservoir 200 which includes a compression spring 222, pushing downwardly on follower plate 208 thereby urging grease 220 under pressure down through reservoir outlet 262 through grease conduit 273 and into grease pump 270. When grease pump 270 is in the open position 292 as depicted in Figure 12 grease 220 under pressure enters in through pump inlet 272 and fills cylinder 275. Piston 274 is urged by cam follower 276 to close off pump inlet 272 as the pump stroke progresses. In the inlet closed position 290 grease is forcibly urged out of cylinder 275 and out through pump outlet 280 and on through grease line 282 which delivers grease to a grease point which in this example is ball joint 284.

[00054] Referring now to an alternate embodiment shown as grease reservoir 300 in Figures 13 and 14 which includes lift rings 302, which are attached to lift lines 304 and extend out through lift line apertures 306 of the lid 304 of grease reservoir 300. Apertures 306 can be sealed with removeable plugs when not in use.

[00055] Referring now to Figure 15 which depicts grease reservoir 400 an alternate embodiment of the present concept which is very similar to grease reservoir 200 and grease reservoir 300 with the exception that included with grease reservoir 400 is a lift mechanism 402 and a pull mechanism 502. [00056] First of all grease reservoir 400 includes glass walls 202 a guide pin 212, a lid 450, a follower plate 480 which pushes upon grease 482 in similar fashion as grease reservoir 200 shown in Figure 4.

[00057] In addition to what is depicted in Figure 4 grease reservoir 400 also includes a lift mechanism 402 and a pull mechanism 502. Lift mechanism 402 includes an advancing mechanism 404 which includes the following components namely a base 416, a lift rod 406, a rack 414, a rod top 418, handles 412 and a rod bottom 422.

[00058] At rod bottom 422 lift rod 406 includes a rod hook 420, which engages with a lift ring 408 which is attached to the rod bottom 422 at one end and to the spring 422 at the other end.

[00059] Advancing mechanism 404 is of the type well known in the art used in for example caulking guns and/or in ratchet and clamping devices. Part of lift rod 406 includes a rack 414which engages with an advancement tooth 415 in order to urge lift rod 406 upwardly thereby lifting upon the bottom of spring 422 therefore relieving the pressure which spring 422 is imparting upon follower plate 480 by effectively lifting spring 422 off of the top of follower plate 480. [00060] In this matter when servicing is required of grease reservoir 400 and/or of grease pump 270 or of the grease conduit 273 out one can temporarily eliminate the effects of spring 422 upon follower plate 480 and therefore relieve the pressure that it imparts upon grease 482. In this manner during servicing operations grease 482 will not come gushing out of open grease conduits 273 or connections to grease pump 270 which may have to be open in order to effect service of the unit.

[00061 ] An alternate lifting mechanism is shown as pull mechanism 502 and includes the following major components namely lift rod 506 which has a T-handle 504, a threaded portion 520 and a nut 522 which impinges upon lid 450. Lift rod 506 includes a swivel 539, a rod top 518 a rod bottom 530 which includes a rod hook 532 which hooks around a lift ring 522 at one end wherein the lift ring connects to spring 422 at the other end.

[00062] By turning on T-handle 504 one rotatably threadably can urge lift rod 506 upwardly or downwardly depending upon the direction of turning of T-handle 504. During a servicing operation for example by threadably turning T-handle 504 such that lift rod 506 is lifted which in turn lifts spring 422 off of the face of follower plate 480 thereby relieving the pressure of the spring 422 on follower plate 480 and the resulting pressures in the grease 482. [00063] Nut 522 is used to lock the lift rod 506 into the desired position during servicing operations.

[00064] The reader will note that lift mechanism 402 and pull mechanism 502 are two examples of the type of mechanisms that could be used to lift spring 422 off of follower plate 480.

[00065] In practice grease reservoir 400 normally would have either two lift mechanisms 402 one extending through each of lift line apertures 306 and/or to pull mechanisms 502 again each extending through lift line apertures 306.

[00066] It is also possible to have one pull mechanism 502 and one lift mechanism 402 as shown in Figure 15 to effect the lifting of spring 422.

[00067] The purpose of lift mechanism 402, pull mechanism 502 or lift ring 302 and lift lines 304 is to enable one to compress spring 422, 322 therefore taking the pressure off of grease 482, 320. This is necessary for example during servicing operations when for example all of the grease outlets have been opened for servicing.

[00068] In this manner the grease can remain in grease reservoir during servicing rather than requiring all of the grease to be drained prior to servicing occurring. In Use

[00069] In automatic greasing systems the grease pumps are typically delivering EP 2 grease at 1 to 6 cc's per minute at 23 rpm which means that the volume per stroke is very small approximately between 1/23 cc and 6/23 cc's per stroke. These are very small drops of grease.

[00070] Additionally it has been found that in low temperature testing at temperatures less than -20°C (minus 20°C) with grease with a base spoil viscosity of 220CST for example that an element that was delivering 6 cc's per minute at 23 rpm at room temperature did not deliver any grease at -20°C. This is due to the fact that the traditional systems rely on atmospheric pressure and a suction that can be created by the grease pump in order to refill the cylinder 275 of the grease pump 270. Due to the increase in viscosity of the grease the grease is not flowing sufficiently fast or not flowing at all through pump inlet and into cylinder 275 in order to fill it with sufficient speed for subsequent pumping through the pump.

[00071] It has been found in practice that by applying a 3 psi pressure head onto the grease 220 within grease compartment 251 one is able to ensure that even very high viscosities will flow and will flow sufficiently through pump inlet 272 to provide for a complete filling of cylinder 275 during each stroke of the grease pump 270. [00072] In fact it has been found that a spring which requires approximately 1401bs to compress into the compressed position 244 pressurizes the grease 222 to approximately 2.5 to 3 psi within grease compartment 251. Experimentally pressures of above 0.5psi have found to be very effective in improving cold temperature grease flow. In practice 0.5 to 6 psi has been found to be effective and 0.5 to 3.0 psi has been found to be adequate.

[00073] In the lower position 230 when the spring 222 is in the extended position 234 the spring delivers approximately 401bs of pressure onto follower plate 208 which translates into approximately 0.7 to 1 psi of pressure on the grease 220 within grease compartment 251. This increase in pressure within grease reservoir 200 is enough that grease having an oil viscosity of 220 Cst can flow sufficiently quickly to provide for full filling of the pump cylinder 275 even at temperatures of -20°C and lower. Therefore by providing a positive pressure on grease 220 within grease compartment 251 in this case using a spring 222 it is possible to pressurize the grease 220 to approximately 3 psi in the spring extended position 234 which provides sufficient flow for the grease to fully fill cylinder 275 even at very cold temperatures.

[00074] Filling of the greasing system generally occurs from a barrel of grease with a hand pump or an air operated pump. During the filling process it is common for air bubbles or air pockets to be entrained in the grease. Additionally when the grease pump is running a vacuum may be generated under the follower plate due to suction from the grease pumps. This vacuum may result is air entering the grease pump at various locations within the pump such as at the cam shaft seal, between the reservoir and follower plate seal, between the guide pin and follower plate bushing, and through the fill connector. With prior art units when this air or air pockets reaches the cylinder 275 of grease pump 270, the cylinder may fill with air rendering the piston 274 unable to pump grease. This is commonly referred to as an airlock situation.

[00075] In the present pressurized system reduces the entrainment of air since there is never a vacuum under the follower plate but always a positive pressure. Additionally any air that enters into cylinder 275 is forced out of cylinder 270 via the positive pressure at pump inlet 272 which positively purges and pushes any air out through pump outlet 280.

[00076] Therefore in addition to the ability to be able to pump grease efficiently at very low temperatures the entire greasing system is resistant to air entrainment and is self-purging able to eliminate air bubbles and air pockets that develop throughout the system. [00077] It should be apparent to persons skilled in the arts that various modifications and adaptation of this structure described above are possible without departure from the spirit of the invention the scope of which defined in the appended claim.