Lubricant applying system and injector means

• US 4,520,902 A
• Filed: 04/19/1983
• Issued: 06/04/1985
• Est. Priority Date: 04/19/1983
• Status: Expired due to Fees

• Current Assignee: Lubriquip, Inc. (Graco Incorporated)
• Original Assignee: Lubriquip-Houdaille Incorporated
• Inventors: Snow, John P.
• Primary Examiner(s): Brown, David H.
• Assistant Examiner(s): Griffiths, John E.
• Application Number:
  US06/486,310
• Time in Patent Office: 777 Days
• Field of Search: 184/1 C, 184/6, 184/6.4, 184/6.28, 184/7 R, 184/7 CR, 184/7 D, 184/7 E, 184/7 F, 184/29, 184/6.1, 184/7.4, 417/225, 417/226, 417/265, 417/304, 417/349, 417/391, 417/401, 417/490, 417/501, 417/521, 137/596.12, 137/596.16, 137/625.69, 91/192, 222/335, 222/389
• US Class Current: 184/7.4
• CPC Class Codes: F16N 25/02 with reciprocating distributing slide valve
• CPC Class Codes: F16N 29/04 enabling a warning to be given; enabling moving parts to be stopped
• CPC Class Codes: Y10T 137/87177 With bypass

Abstract

A lubricant applying system which may have a plurality of lubricant injectors along a lubricant supply/return passage which receives lubricant under predetermined pressure through one end from a source for discharging and sequentially recharging the injector in one phase and in a second phase after the recharging permitting return of surplus lubricant from the injector through the passage to the lubricant source. A pressure sensor connected to the opposite end of the passage monitors pressure conditions in the passage. The lubricant injector has a displacement plunger and a cooperatively related metering plunger. The displacement plunger is responsive to lubricant passage line pressure which drives the displacement plunger in a displacement stroke, during which a passageway is connected by the displacement plunger with a metering chamber from which the metering plunger is driven by the pressure and the metering chamber charged while the metering plunger closes the lubricant passage. Upon release of pressure the displacement plunger is biased in a return stroke, and the metering plunger is biased into a metering stroke for driving the charge of lubricant from the metering chamber into a displacement chamber at the inner end of the displacement plunger. This also opens the lubricant passage for return of surplus lubricant to the source.

Claims

1. A lubricant applying system provided with at least one lubricant injector structure having means for lubricant delivery to at least one respective point of use, and comprising:

a lubricant supply and return passage means connected with said injector structure;

operating means at one end of said passage means functioning cyclically for in one phase supplying lubricant under predetermined pressure from a source through said passage means for sequentially discharging and recharging said injector structure, and for in a second phase and after said recharging permitting return of surplus lubricant from said injector structure in a sequential manner through said passage means to said source;

pressure sensing and signaling means connected to an opposite end of said passage means for monitoring pressure conditions in said passage means;

said at least one injector structure containing a lubricant displacement plunger and a lubricant metering plunger;

means normally biasing said displacement plunger toward one end;

a pressure responsive head on said one end of said displacement plunger for direct exposure to pressure in said passage means for effecting shifting of said displacement plunger in opposition to said biasing means in a lubricant displacement stroke toward its opposite end and into a lubricant displacement chamber at such end from which lubricant is thereby ejected through a port communicating with one of said points of use, the displacement plunger being then returned to said one end upon release of pressure in said passage means;

said injector structure including means completing a metering chamber in combination with one end of said metering plunger and adapted to be substantially occupied by the metering plunger in one operating mode of the metering plunger and to be vacated by the metering plunger in a second operating mode thereof;

said injector structure a passageway connecting said metering chamber with said displacement chamber;

means normally biasing said metering plunger into said one operating mode;

said metering plunger being adapted in said one operating mode for opening said lubricant passage means and by occupying said metering chamber driving lubricant from said metering chamber through said passageway into said displacement chamber, and being adapted in said second operating mode for closing said lubricant passage means and vacating said metering chamber in response to lubricant pressure in said metering chamber; and

said injector structure and said displacement plunger including metering chamber pressurizing and recharging means controlled by said displacement plunger for selectively effecting communication between said lubricant passage means and said passageway in the displacement stroke of said displacement plunger, so that lubricant under pressure will be charged into said metering chamber and cause said metering plunger to shift into said second operating mode and when pressure is released said metering plunger will be shifted into said first operating mode by its biasing means for thereby driving a charge of lubricant from said metering chamber through said passageway into said displacement chamber.

2. A system according to claim 1, wherein said operating means comprises a timer in charge of an electrical driving motor of a pump and also in charge of an electrical control for a valve for alternately connecting said one end of said passage supply/return means with a lubricant source through said pump in said one phase and for connecting said one end of said passage supply/return means with said lubricant source for return of surplus lubricant in said second phase.

3. A system according to claim 1, wherein said operating means includes means for selectively predetermining said pressure.

4. A system according to claim 1, wherein said structure includes a relief duct connecting said pressurizing and recharging means and said passage means for returning lubricant to said passage means after said metering chamber has been filled and while said metering plunger is still in said second operating mode.

5. A system according to claim 1, wherein said metering plunger carries a tell-tale for determining functioning thereof, and said structure includes means for controlling the lubricant volume in the charge of lubricant driven from said metering chamber into said displacement chamber.

6. A system according to claim 1, wherein said pressure sensing and signaling means includes a sensor at said opposite end of said passage means for generating a signal if the pressure in said supply and return passage means line falls below a selected level and a fault indicator connected with said sensor for displaying said signal.

7. A system according to claim 6, wherein said sensor comprises a pressure-sensitive switch and said fault indicator is electrically connected with said switch.

8. A system according to claim 1, including means in said injector structure defining a bore in which said displacement plunger is reciprocatable, said bore having a larger diameter counterbore opening to said passage means and providing an inner end abutment spaced from said passage means, said biasing means for said displacement plunger comprising a coiled compression spring about said displacement plunger and thrusting at one end against said abutment, and said spring having an opposite end against said head.

9. A system according to claim 8, wherein said pressurizing and recharging means comprises a bypass from the inner end of said counterbore and through a valve recess in said displacement plunger communicating with said passageway when the displacement plunger is in said displacement stroke.

10. A system according to claim 1, wherein said structure includes a relief device and passage for dumping lubricant when lubricant pressure in said injector structure exceeds a fixed limit.

11. A system according to claim 10, wherein said metering plunger closes said relief passage when the displacement plunger functions normally in its lubricant displacement stroke.

12. A lubricant applying system injector adapted for connection in supply relationship with a plurality of like lubricant injectors along a lubricant passage adapted for cyclically alternately supplying lubricant under line pressure to the injectors and for releasing pressure therefrom, and each injector adapted for lubricant delivery to a respective point of use, and comprising:

a housing;

displacement plunger and a lubricant metering plunger;

means normally biasing said displacement plunger toward one end;

a pressure responsive head on said one end of said displacement plunger for direct exposure to line pressure in said passage for shifting of said displacement plunger in opposition to said biasing means in a lubricant displacement stroke toward its opposite end and into a lubricant displacement chamber at such end from which lubricant is thereby ejected through a port communicating with said points of use, the displacement plunger being then returned to said one end upon said release of pressure in said lubricant passage;

said housing including means completing a metering chamber in combination with one end of said metering plunger and adapted to be substantially occupied by the metering plunger in one operating mode of the metering plunger and to be vacated by the metering plunger in a second operating mode thereof;

said housing including a passageway connecting said metering chamber with said displacement chamber;

means normally biasing said metering plunger into said one operating mode;

said metering plunger being adapted in said one operating mode for opening said lubricant passage and by occupying said metering chamber driving lubricant from said metering chamber through said passageway into said displacement chamber, and being adapted in said second operating mode for closing said lubricant passage and vacating said metering chamber in response to lubricant pressure in said metering chamber; and

said housing and said displacement plunger including metering chamber pressurizing and recharging means controlled by said displacement plunger for selectively effecting communication between said lubricant passage and said passageway in the displacement stroke of said displacement plunger, so that lubricant under pressure will be charged into said metering chamber and cause said metering plunger to shift into said second operating mode and when the pressure is released said metering plunger will be shifted into said first operating mode by its biasing means for thereby driving a charge of lubricant from said metering chamber through said passageway into said displacement chamber.

13. A lubricant applying system injector according to claim 12, wherein said pressurizing and recharging means comprises a bypass through a valve recess in said displacement plunger communicating with said passageway when the displacement plunger is in said displacement stroke relation.

14. A lubricant applying system injector according to claim 12, wherein said housing includes a relief duct connecting said pressurizing and recharging means and said passage for returning pressure lubricant to said passage.

15. A lubricant applying system injector according to claim 12, wherein said housing includes a relief duct connecting said pressurizing and recharging means and said passage for returning lubricant to said passage after said metering chamber has been filled and while said metering plunger is still in said second operating mode.

16. A lubricant applying system injector according to claim 12, wherein said housing includes a bypass passage branch for dumping lubricant away from said displacement plunger when the displacement plunger fails to respond to line pressure imposed on said head, and said metering plunger closing said bypass passage branch when said displacement plunger functions properly in its lubricant displacement stroke.

17. A lubricant applying system injector according to claim 12, wherein said metering plunger carries a tell-tale for determining functioning thereof, and means for controlling the lubricant volume in the charge of lubricant driven from said metering chamber into said displacement chamber.

18. A system for supplying lubricant to a plurality of points from a lubricant source comprising:

a plurality of injectors respectively communicating with said points for delivering said lubricant thereto, each said injector having a housing;

a lubricant supply and return line passing through all of said injectors;

a pumping means for connecting to said lubricant source and connected to said lubricant supply and return line through a valve means and a control means operating said pumping means and said valve means in combination for periodically supplying lubricant under pressure through said lubricant supply and return line to each of said injectors during a supply phase of operation and for stopping supply of lubricant and connecting said lubricant supply and return line to said lubricant source during a following return phase of operation;

each of said injector housings having a displacement chamber communicating with one of said points and a displacement plunger movable in said displacement chamber, said displacement plunger having a head normally disposed by a first bias means for direct exposure to pressurized lubricant supplied during said supply phase in said lubricant supply and return line forcing said plunger against said first bias means expelling lubricant from said displacement chamber to said one point;

each of said injector housings further having a metering chamber with a metering plunger movable therein, said metering plunger disposed for moving through said supply and return line against a second bias means and having blocking means normally disposed out of said supply and return line;

each of said injector housings further having a first passage connecting said displacement chamber and said metering chamber, said first passage being normally closed to said supply and return line by said displacement plunger when said pumping means is off and being opened to said receive lubricant from said supply and return line by movement of said displacement plunger during said supply phase permitting flow of lubricant through said fist passage to said metering chamber forcing said metering plunger against said second bias means such that said blocking means blocks said supply and return line;

each of said injector housings and said diplacement plungers further having a metering chamber pressurizing and recharging means controlled by its said displacement plunger for selectively effecting communication between said lubricant supply and return line and its said first passage in strokes of said displacement plunger expelling lubricant from its said displacement chamber, so that during said supply phase said metering chamber is charged with lubricant under pressure causing its said metering plunger to shift compressing its said second bias means, and during said return phase said second bias means forces said metering plunger into said metering chamber expelling lubricant therein through said first passage to said displacement chamber for recharging said displacement chamber, said first bias means moving said displacement plunger to a position closing said first passage to said supply and return line, and said blocking means being moved out of said supply and return line permitting return of excess lubricant therethrough from said other injectors to said lubricant source; and

each of said injector housings further having a second passage connected to said metering chamber pressurizing and recharging means and to said supply and return line enabling lubricant to bypass said blocking means to supply lubricant to said other injectors when said supply and return line is blocked by said blocking means.