CA1224671A - Pump for supplying a liquid additive to a flow of liquid - Google Patents
Pump for supplying a liquid additive to a flow of liquidInfo
- Publication number
- CA1224671A CA1224671A CA000438330A CA438330A CA1224671A CA 1224671 A CA1224671 A CA 1224671A CA 000438330 A CA000438330 A CA 000438330A CA 438330 A CA438330 A CA 438330A CA 1224671 A CA1224671 A CA 1224671A
- Authority
- CA
- Canada
- Prior art keywords
- operating
- switching means
- fluid
- pump
- dosing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B9/00—Piston machines or pumps characterised by the driving or driven means to or from their working members
- F04B9/08—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid
- F04B9/10—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid
- F04B9/103—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having only one pumping chamber
- F04B9/105—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having only one pumping chamber reciprocating movement of the pumping member being obtained by a double-acting liquid motor
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01C—PLANTING; SOWING; FERTILISING
- A01C23/00—Distributing devices specially adapted for liquid manure or other fertilising liquid, including ammonia, e.g. transport tanks or sprinkling wagons
- A01C23/04—Distributing under pressure; Distributing mud; Adaptation of watering systems for fertilising-liquids
- A01C23/042—Adding fertiliser to watering systems
Abstract
A PUMP FOR SUPPLYING A LIQUID ADDITIVE TO A FLOW OF LIQUID
ABSTRACT OF DISCLOSURE
This pump comprises a dosing chamber 11 communicating with inlet and outlet openings 12, 13 for a liquid additive. A displaceable member 20, which dispenses the liquid additive, is connected by connection means 30 to displaceable member 40 in an operating chamber 50 with first and second chambers 51, 52 and ports 53, 54. Operating switching means 60 controls the supply of operating fluid to said ports 53, 54 in such manner that when one chamber (51, 52) is supplied with operating fluid the other chamber (52, 51) is evacuated: successive switching thereof effects reciprocation of the connection means 30 and dispenses measured quantities of liquid additive. The operating switching means 60 is fluid actuated. A pilot switching means 70 is mechanically associated with said reciprocating connection means 30 and is coupled by fluid couplings 81, 82 to switching means 60 such that, at the end of each stroke of the reciprocating correction means 30, the switching means 60 is actuated to change the supply of operating fluid 55 from one to the other of operating chambers 51, 52.
ABSTRACT OF DISCLOSURE
This pump comprises a dosing chamber 11 communicating with inlet and outlet openings 12, 13 for a liquid additive. A displaceable member 20, which dispenses the liquid additive, is connected by connection means 30 to displaceable member 40 in an operating chamber 50 with first and second chambers 51, 52 and ports 53, 54. Operating switching means 60 controls the supply of operating fluid to said ports 53, 54 in such manner that when one chamber (51, 52) is supplied with operating fluid the other chamber (52, 51) is evacuated: successive switching thereof effects reciprocation of the connection means 30 and dispenses measured quantities of liquid additive. The operating switching means 60 is fluid actuated. A pilot switching means 70 is mechanically associated with said reciprocating connection means 30 and is coupled by fluid couplings 81, 82 to switching means 60 such that, at the end of each stroke of the reciprocating correction means 30, the switching means 60 is actuated to change the supply of operating fluid 55 from one to the other of operating chambers 51, 52.
Description
7~
A PUMP FOR SUPPLYING A LIQUID ADDITIVE
rro A FLOW OF LIQUID
This invention relates to a pump for supplying a liquid additive to a ~low o~ liquid, Pumps for this puxpose are well known, see for example oU~E~ Patent Nos. 1243732 and 1387880, Both o~ those 5 pumps are primarily for use in horticul-ture i.e. for introducing quantities o~ liquid -fertilizer into irrigation water. Whilst they operate satisfactorily in their intended en~ironment, in particular they overcome the problem of injecting additive into flowing 10 liquid9 they are not the first choice o~ pump ~or certain other environments e,g. environments where there is no electricity i.e~ remote rural areas, or environments where ~ire hazards have to be avoided at all costs e.g. in petro-chemical industrial plant. For use in 15 petro-chemical industrial plant, pumps may be ~lame proo~ed and other appropriate measure may be taken. However these measures in themselves tend to greatly increase the production costs of the pumps.
A PUMP FOR SUPPLYING A LIQUID ADDITIVE
rro A FLOW OF LIQUID
This invention relates to a pump for supplying a liquid additive to a ~low o~ liquid, Pumps for this puxpose are well known, see for example oU~E~ Patent Nos. 1243732 and 1387880, Both o~ those 5 pumps are primarily for use in horticul-ture i.e. for introducing quantities o~ liquid -fertilizer into irrigation water. Whilst they operate satisfactorily in their intended en~ironment, in particular they overcome the problem of injecting additive into flowing 10 liquid9 they are not the first choice o~ pump ~or certain other environments e,g. environments where there is no electricity i.e~ remote rural areas, or environments where ~ire hazards have to be avoided at all costs e.g. in petro-chemical industrial plant. For use in 15 petro-chemical industrial plant, pumps may be ~lame proo~ed and other appropriate measure may be taken. However these measures in themselves tend to greatly increase the production costs of the pumps.
- 2 -It is there$ore an object of the present invention to provide a pump which is suitable -for use in a wide range of environments, whether industrial, agricultural or horticultural 9 and which does not depend ior its operation on an electricity supply, and finally, which is of a simple and economic construction to manufacture and service~ According to one aspect of the present invention there is provided a pump for supplying liquid additive to a flow of liquidS comprising a aosing chamber communicating with an inlet opening and an outlet opening for a liquid additive, each said opening-being controlled by a non return valve~ a first displaceable member arranged in said dosing cha~ber and operative to dispense said liquid additive, said first displaceable member being operatively connected byconnection means to a second displaceable member arranged iIl an opera-ting chamber, said second displaceable member being arranged $o partition said operating chamber into ~irst and second opera-ting chambers, each of said first and second operating chambers having a respective por-t for CQmmuniCatiOn with a supply o~ operating ~luid~ operating switc~ing means ~or controlling the supply of operating fluid to said ports of said ~irst and second operating chambers, said operating switching means being operative such that when one of said first and second operating chambers is being supplied with operating fluid the respective other operating chamber is being evacuated whereby successi.ve switching of said operating switching means effects reciprocation of said connection means and thereby dispensing oi measured qua~tities o~ liquid additive from the ~osing chamber, wherein said operating switching means is fluid actuated9 and a pilot switching means is mechanically associated with said reciprocating connection moans ~2~6 and is operati~ely coupled by ~luid couplings to the ~luid actuated operating switching means, the pilot switching means and the ~luid actuated switching means thus coupled being operable such that, at the end o~ each stroke of the reciprocating connection means~ said ~luid ac-tuated switching means is actuated to change the supply o~ operating fluid ~rom one to the other of said operating chambers.
In the pre~erred embodiment said first displaceable member is a piston, said dosing chamber is arrangad wi-thin a dosing head, said second displaceable member is an operating diaphram, said operating chambers are de~ined by an operating head, and the connectior means includes piston rod means coupled with both displaceable members Embodiments o~ such a pump may be constructed to operate with either hydraulic or p~eumatic actuation i.e. with either a liquid, ~or example water, or air as the operating ~luid which is supplied and evacuated from the ~irst and second operating chambers.
In a particular application namely in a water puri~ication system ~or the supply o~ puri~ied water for domestic purposes in isolated villages in under-developed territories, the operating ~luid may be the water which is being purified. This water may be pumped, for exampleJ by a diesel pump to a village ~0 reservoir and the pressure of the water in transit may be employed to drive this pump ~or the additive (i.e. agent ~or puri~ying the water). In this case~
it should be appreciated that the water evacuated from the ~irst and second opera-ting chambers is directed back to ~ource, whereby the precious co~odity (water) is not lost.
~L2~
On the other hand, the pump may be pneumatically actuated, for example, in industrial environments where it is common place for there to be an abundant supply of compressed air for driving industrial plant.
In this case since the volumes of air used by this pump are rela-tively small, the air ~rom the first and second operating chambers ma~ be evacuated to atmosphere.
In a preferred embodi~ent, the fluid actuated switching means is a spool valve or a slide valve which is actuated under fluid con-trol by the pilot switching means, -the condition of said pilot switching l~eans controlling the application of pilot operating fluid from said pilot switchirlg means to said fluid actuated switching means and thereby the selection of which of said firs-t and second operating chambers is supplied with operating fluid.
In the preferred embodiment, said pilot switching means is a spool or slide valve arranged to control by fluid control the fluid actuated switching means and itself being mechanically actuated to change state at each end ofeach s-troke o~ thereciprocating connection means bymeansof actuating stopsassociated with the reciprocating connection means.
It should be appreciated that the chambersi~ the operating head and dosing head may be relatively proportioned (that is to say the effective piston area and diaphram area may be relatively proportioned) as to ensure that the pressure of the additive leaving the ~osing head is sufficient for injection of the addi-tive into the liquid i~to which it is to be mixed. It will be readily appreciated that the outlet of the dosing head may be coupled to a vessel or pipework through which said liquid is flowing. Typical values of the , .
mechanical advantage which may be obtained with embodiments of the pu~ps herein defined arc ~rom 11:1 down to 2.5:1. A ratio of ll:i indicates that the pressure of the liquid to be dosed may be eleven times greater than the pressure of the operating fluid. It is an advantageous feature o~ the construction o~ embodiments of the invention that the size of dosing head and piston associated therewith may be a customised unit with the remainder of the structure defining the pump being of standard components.
The aforegoing defined pUlUp with a single dosing head may be termed a "simplex" pump By the addition of a second dosing head itself having a secondconnection means operatively connected with said member, a "duple~"
pump is provided whereby the pump is capable of metering additive via each of the two dosing heads.
~he additives dosedby the two dosing heads may be the same additives, for example, to two dif~erent flows of liquid or different additives, for example7 to the same flow of liquid. The dosing capacity o~ the two dosing heads may be the same or different.
The volw~e of additive passed by the or each dosing head on each actuation thereof may be adjustable.
~ For this purpose the connection between the ~ember of ; the dosing head and the member oft~s operating head may include a variable lost motion coupling thereby to adjust the effective stroke of theconnee-tion means.
The lost motion coupling preferably has cali~ration means giving a visual indication of the dosing rate of the dosingchamber f~ different settings of the lost motion coupling.
~2~7 An embodiment o~ the invention will now be described by way ol' example only~ with reference t~ the accompanying drawing which shows in sectional elevation a pump ~or supplying a liqLuid additive to a flow o~ liquidO
In the drawing there is shown a "simplex" pump ~or supplying a liquid additive to a flow o-i liquid. A
dosing head 10 defines a dosing chamber il communicating with an inlet opening 12 and an outlet opening 13 for a liquid additive. Each of the ~enings i2, 13 is controlled by a respective non re-turn valve 15.
A ~irst displaceable member 20, which is in the ~orm oi a piston member, is arranged in the dosing chamber 11 and is operative to dispense said liquid additive through the outlet opening 13. This ~irst displaceable member 20 is opera-tively connected by connection means 30 (to be ~urther described) to 2 second displaceable member 40, the latter being arranged in an operating cham~er 50. ~he second displaceable member 40, which is in the ~orm of a diaphragm, is arranged to partition operating chamber 50 into ~irst and second operating chambers 51, 52. Each of the ~irst and second operating chambers 51, 52 having a respective port 53~ 54 for communication wi-th a supply o~ operating ~luid 55.
Operating switching means 60 controls the supply o~
operating ~luid 55 to the ports 53, 54 o~ the ~irst an~
second operating chambers 51, 52. This operating : switching means 60 is operative such that when one o~
said first and second operating chambers 51, 52 is being supplied via supply line 61 with operating ~luid 55, the respective other one of the operating chambers 52, 52 is being evacuated via evacuation line ~20 Successive switching operations oi the operating switching means 60 thereby e~ects reciprocation o~
~2 the connection means 30 and also thereby the dispensing of measured quantiti~s O:e liquid additive from the dosing chamber 11~ The operating switching me~ns 60 is fluid actuated, i~e the pressure in - 5 control lines 819 82 ~to be further described) controls the position of the slide or spool valve therein. A pilo-t switching means 70 is me¢hanically associated (as will be ~ur-ther describecl~ with the reciprocating connection means 30. The pilot switching means 70 is operatively coupled by ~luid couplings via lines 81 to 85 to the operating switching means 60.
The pilot switching means 70 and the operating switching means 60 are operable such that9 at the end of each stroke of the reciprocatlng connectio~ means 30~ the operating switching means 60 is actuated to change the supply o~ operating fluid 55 from one to the other of the ports 53, 54 and hence ~rom one to the other of the operating chambers 51, 52.
The operating chambers 51, 52 are defined by an operating head 90 which, as is evident from the drawing, is in two parts 91~ 92 bolted together at 93 to clamp the diaphragm means 40 (o~ the second displaceable member) abou-t its periphery~ The two operating head parts 9i, 92 are ~ormed so as to define the chamber 50 therebetween which is partitioned into operating chambers 51, 52 by the diaphragm means ~0. Diaphragm means 40 is itsel~ provided with stiffening discs 41 maintained in clamped attitude by locking means ~2 threadedly engaged with one portion 32 o~ the connection means 30.
In addition head parts 91~ 92 are ~ormed to define passages 95; 96 which at their outer ends are threadedly engaged by connecting pieces 97, 98. These connecting pieces 97, 98 couple lines 63, 64 to the operating head 90 and also define the aforesaid openings 53, $4.
~2~6~71 In addition part 91 is provided with a passage 94 which accommodates a guide pieoe 99 in threaded engagement therewith. Guide piece 99 guides the connecting means 30 in the head part 91. 0-ring seals 18 are located in passage 94 to co-operate with guide piece 99. It will be appreciated that as shown head part 92 has a recess axially aligned with the passage 94 to accommodate the end 37 of the connection means 30 on its rightward travel (as seen in the dra~ing). It should be appreciated from the aforegoing generalised comments concerning a "duplex"
pump, that for such a pump the operating head part 92 would also have a passage 94 extended through the outer wall thereof to accommodate its respective connection means 30 for another dosing head 20 (not shown).
The connection means 30 includes piston rod means 31, 32 connected respectively to the displaceable members 20, 40 (i.e. the piston and the diaphragm). As shown the piston rod means 31, 32 are associated with a main piston rod part 33~ Part 33 is directly connected with piston rod means 32 and thereby the diaphragm means tsecond displaceable member 40). Part 33 is connected to.
piston rod mears 31 by means o~ a lost motion coupling including members 34, 35. By the setting of member 35 relative to the part 33 so the degree of lost motion will be determined. It will be seen that the forward end 36 of the part 33 enters an axial cavity in the part 31, this ensures that the end 36 is supported at all times. However, as
In the pre~erred embodiment said first displaceable member is a piston, said dosing chamber is arrangad wi-thin a dosing head, said second displaceable member is an operating diaphram, said operating chambers are de~ined by an operating head, and the connectior means includes piston rod means coupled with both displaceable members Embodiments o~ such a pump may be constructed to operate with either hydraulic or p~eumatic actuation i.e. with either a liquid, ~or example water, or air as the operating ~luid which is supplied and evacuated from the ~irst and second operating chambers.
In a particular application namely in a water puri~ication system ~or the supply o~ puri~ied water for domestic purposes in isolated villages in under-developed territories, the operating ~luid may be the water which is being purified. This water may be pumped, for exampleJ by a diesel pump to a village ~0 reservoir and the pressure of the water in transit may be employed to drive this pump ~or the additive (i.e. agent ~or puri~ying the water). In this case~
it should be appreciated that the water evacuated from the ~irst and second opera-ting chambers is directed back to ~ource, whereby the precious co~odity (water) is not lost.
~L2~
On the other hand, the pump may be pneumatically actuated, for example, in industrial environments where it is common place for there to be an abundant supply of compressed air for driving industrial plant.
In this case since the volumes of air used by this pump are rela-tively small, the air ~rom the first and second operating chambers ma~ be evacuated to atmosphere.
In a preferred embodi~ent, the fluid actuated switching means is a spool valve or a slide valve which is actuated under fluid con-trol by the pilot switching means, -the condition of said pilot switching l~eans controlling the application of pilot operating fluid from said pilot switchirlg means to said fluid actuated switching means and thereby the selection of which of said firs-t and second operating chambers is supplied with operating fluid.
In the preferred embodiment, said pilot switching means is a spool or slide valve arranged to control by fluid control the fluid actuated switching means and itself being mechanically actuated to change state at each end ofeach s-troke o~ thereciprocating connection means bymeansof actuating stopsassociated with the reciprocating connection means.
It should be appreciated that the chambersi~ the operating head and dosing head may be relatively proportioned (that is to say the effective piston area and diaphram area may be relatively proportioned) as to ensure that the pressure of the additive leaving the ~osing head is sufficient for injection of the addi-tive into the liquid i~to which it is to be mixed. It will be readily appreciated that the outlet of the dosing head may be coupled to a vessel or pipework through which said liquid is flowing. Typical values of the , .
mechanical advantage which may be obtained with embodiments of the pu~ps herein defined arc ~rom 11:1 down to 2.5:1. A ratio of ll:i indicates that the pressure of the liquid to be dosed may be eleven times greater than the pressure of the operating fluid. It is an advantageous feature o~ the construction o~ embodiments of the invention that the size of dosing head and piston associated therewith may be a customised unit with the remainder of the structure defining the pump being of standard components.
The aforegoing defined pUlUp with a single dosing head may be termed a "simplex" pump By the addition of a second dosing head itself having a secondconnection means operatively connected with said member, a "duple~"
pump is provided whereby the pump is capable of metering additive via each of the two dosing heads.
~he additives dosedby the two dosing heads may be the same additives, for example, to two dif~erent flows of liquid or different additives, for example7 to the same flow of liquid. The dosing capacity o~ the two dosing heads may be the same or different.
The volw~e of additive passed by the or each dosing head on each actuation thereof may be adjustable.
~ For this purpose the connection between the ~ember of ; the dosing head and the member oft~s operating head may include a variable lost motion coupling thereby to adjust the effective stroke of theconnee-tion means.
The lost motion coupling preferably has cali~ration means giving a visual indication of the dosing rate of the dosingchamber f~ different settings of the lost motion coupling.
~2~7 An embodiment o~ the invention will now be described by way ol' example only~ with reference t~ the accompanying drawing which shows in sectional elevation a pump ~or supplying a liqLuid additive to a flow o~ liquidO
In the drawing there is shown a "simplex" pump ~or supplying a liquid additive to a flow o-i liquid. A
dosing head 10 defines a dosing chamber il communicating with an inlet opening 12 and an outlet opening 13 for a liquid additive. Each of the ~enings i2, 13 is controlled by a respective non re-turn valve 15.
A ~irst displaceable member 20, which is in the ~orm oi a piston member, is arranged in the dosing chamber 11 and is operative to dispense said liquid additive through the outlet opening 13. This ~irst displaceable member 20 is opera-tively connected by connection means 30 (to be ~urther described) to 2 second displaceable member 40, the latter being arranged in an operating cham~er 50. ~he second displaceable member 40, which is in the ~orm of a diaphragm, is arranged to partition operating chamber 50 into ~irst and second operating chambers 51, 52. Each of the ~irst and second operating chambers 51, 52 having a respective port 53~ 54 for communication wi-th a supply o~ operating ~luid 55.
Operating switching means 60 controls the supply o~
operating ~luid 55 to the ports 53, 54 o~ the ~irst an~
second operating chambers 51, 52. This operating : switching means 60 is operative such that when one o~
said first and second operating chambers 51, 52 is being supplied via supply line 61 with operating ~luid 55, the respective other one of the operating chambers 52, 52 is being evacuated via evacuation line ~20 Successive switching operations oi the operating switching means 60 thereby e~ects reciprocation o~
~2 the connection means 30 and also thereby the dispensing of measured quantiti~s O:e liquid additive from the dosing chamber 11~ The operating switching me~ns 60 is fluid actuated, i~e the pressure in - 5 control lines 819 82 ~to be further described) controls the position of the slide or spool valve therein. A pilo-t switching means 70 is me¢hanically associated (as will be ~ur-ther describecl~ with the reciprocating connection means 30. The pilot switching means 70 is operatively coupled by ~luid couplings via lines 81 to 85 to the operating switching means 60.
The pilot switching means 70 and the operating switching means 60 are operable such that9 at the end of each stroke of the reciprocatlng connectio~ means 30~ the operating switching means 60 is actuated to change the supply o~ operating fluid 55 from one to the other of the ports 53, 54 and hence ~rom one to the other of the operating chambers 51, 52.
The operating chambers 51, 52 are defined by an operating head 90 which, as is evident from the drawing, is in two parts 91~ 92 bolted together at 93 to clamp the diaphragm means 40 (o~ the second displaceable member) abou-t its periphery~ The two operating head parts 9i, 92 are ~ormed so as to define the chamber 50 therebetween which is partitioned into operating chambers 51, 52 by the diaphragm means ~0. Diaphragm means 40 is itsel~ provided with stiffening discs 41 maintained in clamped attitude by locking means ~2 threadedly engaged with one portion 32 o~ the connection means 30.
In addition head parts 91~ 92 are ~ormed to define passages 95; 96 which at their outer ends are threadedly engaged by connecting pieces 97, 98. These connecting pieces 97, 98 couple lines 63, 64 to the operating head 90 and also define the aforesaid openings 53, $4.
~2~6~71 In addition part 91 is provided with a passage 94 which accommodates a guide pieoe 99 in threaded engagement therewith. Guide piece 99 guides the connecting means 30 in the head part 91. 0-ring seals 18 are located in passage 94 to co-operate with guide piece 99. It will be appreciated that as shown head part 92 has a recess axially aligned with the passage 94 to accommodate the end 37 of the connection means 30 on its rightward travel (as seen in the dra~ing). It should be appreciated from the aforegoing generalised comments concerning a "duplex"
pump, that for such a pump the operating head part 92 would also have a passage 94 extended through the outer wall thereof to accommodate its respective connection means 30 for another dosing head 20 (not shown).
The connection means 30 includes piston rod means 31, 32 connected respectively to the displaceable members 20, 40 (i.e. the piston and the diaphragm). As shown the piston rod means 31, 32 are associated with a main piston rod part 33~ Part 33 is directly connected with piston rod means 32 and thereby the diaphragm means tsecond displaceable member 40). Part 33 is connected to.
piston rod mears 31 by means o~ a lost motion coupling including members 34, 35. By the setting of member 35 relative to the part 33 so the degree of lost motion will be determined. It will be seen that the forward end 36 of the part 33 enters an axial cavity in the part 31, this ensures that the end 36 is supported at all times. However, as
3~ the part 33 advances to the left (in the drawing) no motion of the part 31 (and hence piston or first displaceable -member 20) occurs until member 35 abuts member 34 of the lost motion coupling. It will be seen that the member 35 is threadedly engaged at 38 with the part 33 whereby the degree of lost motion may be varied. In this way the ~olume of additive dispensed by the - g - ~L2~6~
dosing head 10 on each ao-tuation thereof is adjustable.
By varying the posi$ion of the member 35 relative to the part 33, the effective stroke of the connection means ~0 is adjusted.
As can be seen, the lost motion coupling formed by members 34~ 35 is associated with ca,libration means comprising a threaded member 111 threadedly engaging a threaded passage in the member 34 and ~reely displaceable with respect to an associated passage 112 in the mem~er 350 This member 111 carries a pair of calibration discs 113, ~14. On part ~3 of the connection means 30 is calibrated marker piece 115 which is threadedly engageable therewith at the threaded portion 38. l'he disposl-tion o~ the calibra-tion discs 113, 114 relative to the oalibrated marker piece 115 enables the dosing capacity of the dosing head 10 to be read off for each o~ a series of adjustments o~ the lost motion coupling (349 35), It will be observed that the dosing head 10 accommodates the piston or displaceable me~ber 20 in the cavity therein 11. It will be no-ted tha-t dosing head 10 is bolted at 122 to a framework 120 which is connected to -the operating head 90 by further bol-ts 121. Within dosing head 10 are passages which are threaded to accommodate the members 16, 17 incorporating the non return valves 15. It will be noted that O-ring seals 18 seal the joints between members 16, 17 and the dosing head lV~
~0 Likewise, within the chamber 11 the piston 20 carries piston rings 21 to ensure a seal with respect to chamber llo Piston 20 is guided by guide piece 29.
llhe fluid aotuated switching means 60 is a spool valve or slide valve. It is actuated under fluid control by ~L2~4~7~L
the pilot switching means 70. As can be seen the pilot switching means 70 has a spool 77 (i-t could be a slide). The position of this spool 77 (which is determined as will be ~urther described) determines the internal condition o~ said pilot switching means 70.
~his internal condition determines whether pilot pressure ~luid issues from port 71 or port 72 an~ thus enters switching means 60 via a respective one of lines 81, 82. When the pilot pressure fluid is applied . 10 along line 81, the internal condition of the switching means 60 is such that the operating -flu-ld 55 passes to line 63 and thence operating chamber 51, whilst pressure ~luid in chamber 52 is permitted to be e~acuated slnce line 64 is now in communication with evacuation line 62.
However, when switching means 70 changes its internal condition7 the pilot fluid pressure is then applied along line 82. This causes the inte~nal condition o~
switching means 60 to change state~ In consequence line 64 is connected to the line 61 so that chamber 52 is pressurized, whilst chamber 51 is evacuated as line 63 is now coupled to evacuation line 62. Thus the co~dition o~ thc pilot switching mean~ 70 controls the application o~ pilot operating ~luid from said pilot switching means 70 to the switching means 60 and thereby the selection of which o~ the first and second operating chambers 51, 52 is supplied with operating ~lui~ 55~
The pilot switching means 70, which is also a spool or slide valve, is itself mechanically actuated -to change state at each end of each stroke o~ the reciprocating connection ~eans 30. The spool 77 (it may be a slide) is acted upon by s-tops 1~1, 132 arranged to contact, and displace, a respective end of spool 77 at the transition point in the movement of connection means 30. Stop 131, which in this embodiment is ~ormed by a 67; ~
bolt, is carried by the lost motion coupling member 35 and is adjustable relative thereto, whereby the switch~ng point may be adjusted. Stop 132 is carried by a member 133. Member 133 is slideably mounted on ths connection means part 33 and adjustably securecl thereto by fastening means 134. Since the position o~ member 133 relative to part 33 m~y be adjusted, as ma~ ~ember 132 relative to member 133~ it ~ollows that the switching point of the switching means 70 may also be adjusted or tuned relative to the respective transition or end of stroke of the connection means 30. As stated, direct contact of the spool 77 with one of the stops i31 or 132 causes the position of spool 77 to change wi-th respec-t to the housing thexeof, In conse~uence the condition of the swi-tching means 70 changes with the resultant change of pilot pressure fluid between the lines 81~ 82 ~as described above). It will he noted that pilot switching means 70 has ~ive ports 71 -to 75 communicating with lines 81 to 85. I.ines 81, 82 have ~een explained. Line 85 is the pressure -fluid supply line and is connected to the main supply line 610 Lines 83, 84 are the exhaust lines for exhausting as appropriate a respective one of lines 81, 82 when the other of those lines is pressurised, and these lines 83, 84 are connected to the main evacuation line 62.
dosing head 10 on each ao-tuation thereof is adjustable.
By varying the posi$ion of the member 35 relative to the part 33, the effective stroke of the connection means ~0 is adjusted.
As can be seen, the lost motion coupling formed by members 34~ 35 is associated with ca,libration means comprising a threaded member 111 threadedly engaging a threaded passage in the member 34 and ~reely displaceable with respect to an associated passage 112 in the mem~er 350 This member 111 carries a pair of calibration discs 113, ~14. On part ~3 of the connection means 30 is calibrated marker piece 115 which is threadedly engageable therewith at the threaded portion 38. l'he disposl-tion o~ the calibra-tion discs 113, 114 relative to the oalibrated marker piece 115 enables the dosing capacity of the dosing head 10 to be read off for each o~ a series of adjustments o~ the lost motion coupling (349 35), It will be observed that the dosing head 10 accommodates the piston or displaceable me~ber 20 in the cavity therein 11. It will be no-ted tha-t dosing head 10 is bolted at 122 to a framework 120 which is connected to -the operating head 90 by further bol-ts 121. Within dosing head 10 are passages which are threaded to accommodate the members 16, 17 incorporating the non return valves 15. It will be noted that O-ring seals 18 seal the joints between members 16, 17 and the dosing head lV~
~0 Likewise, within the chamber 11 the piston 20 carries piston rings 21 to ensure a seal with respect to chamber llo Piston 20 is guided by guide piece 29.
llhe fluid aotuated switching means 60 is a spool valve or slide valve. It is actuated under fluid control by ~L2~4~7~L
the pilot switching means 70. As can be seen the pilot switching means 70 has a spool 77 (i-t could be a slide). The position of this spool 77 (which is determined as will be ~urther described) determines the internal condition o~ said pilot switching means 70.
~his internal condition determines whether pilot pressure ~luid issues from port 71 or port 72 an~ thus enters switching means 60 via a respective one of lines 81, 82. When the pilot pressure fluid is applied . 10 along line 81, the internal condition of the switching means 60 is such that the operating -flu-ld 55 passes to line 63 and thence operating chamber 51, whilst pressure ~luid in chamber 52 is permitted to be e~acuated slnce line 64 is now in communication with evacuation line 62.
However, when switching means 70 changes its internal condition7 the pilot fluid pressure is then applied along line 82. This causes the inte~nal condition o~
switching means 60 to change state~ In consequence line 64 is connected to the line 61 so that chamber 52 is pressurized, whilst chamber 51 is evacuated as line 63 is now coupled to evacuation line 62. Thus the co~dition o~ thc pilot switching mean~ 70 controls the application o~ pilot operating ~luid from said pilot switching means 70 to the switching means 60 and thereby the selection of which o~ the first and second operating chambers 51, 52 is supplied with operating ~lui~ 55~
The pilot switching means 70, which is also a spool or slide valve, is itself mechanically actuated -to change state at each end of each stroke o~ the reciprocating connection ~eans 30. The spool 77 (it may be a slide) is acted upon by s-tops 1~1, 132 arranged to contact, and displace, a respective end of spool 77 at the transition point in the movement of connection means 30. Stop 131, which in this embodiment is ~ormed by a 67; ~
bolt, is carried by the lost motion coupling member 35 and is adjustable relative thereto, whereby the switch~ng point may be adjusted. Stop 132 is carried by a member 133. Member 133 is slideably mounted on ths connection means part 33 and adjustably securecl thereto by fastening means 134. Since the position o~ member 133 relative to part 33 m~y be adjusted, as ma~ ~ember 132 relative to member 133~ it ~ollows that the switching point of the switching means 70 may also be adjusted or tuned relative to the respective transition or end of stroke of the connection means 30. As stated, direct contact of the spool 77 with one of the stops i31 or 132 causes the position of spool 77 to change wi-th respec-t to the housing thexeof, In conse~uence the condition of the swi-tching means 70 changes with the resultant change of pilot pressure fluid between the lines 81~ 82 ~as described above). It will he noted that pilot switching means 70 has ~ive ports 71 -to 75 communicating with lines 81 to 85. I.ines 81, 82 have ~een explained. Line 85 is the pressure -fluid supply line and is connected to the main supply line 610 Lines 83, 84 are the exhaust lines for exhausting as appropriate a respective one of lines 81, 82 when the other of those lines is pressurised, and these lines 83, 84 are connected to the main evacuation line 62.
Claims (8)
1. A pump for supplying liquid additive to a flow of liquid, comprising a dosing chamber communicating with an inlet opening and an outlet opening for a liquid additive, each said opening being controlled by a non return valve, a first displaceable member arranged is said dosing chamber and operative to dispense said liquid additive, said first displaceable member being operatively connected by connection means to a second displaceable member arranged in an operating chamber, said second displaceable member being arranged to partition said operating chamber into first and second operating chambers, each of said first and second operating chambers having a respective port for communication with a supply of operating fluid, operating switching means for controlling the supply of operating fluid to said ports of said first and second operating chambers, said operating switching means being operative such that when one of said first and second operating chambers is being supplied with operating fluid the respective other operating chamber is being evacuated whereby successive switching of said operating switching means effects reciprocation of said connection means and thereby dispensing of measured quantities of liquid additive from the dosing chamber, wherein said operating switching means is fluid actuated, and a pilot switching means is mechanically associated with said reciprocating connection means and is operatively coupled by fluid couplings to the fluid actuated operating switching means, the pilot switching means and the fluid actuated switching means thus coupled being operable such that, at the end of each stroke of the reciprocating connection means, said fluid actuated switching means is actuated to change the supply of operating fluid from one to the other of said operating chambers, and wherein the volume of liquid additive dispensed by the dosing chamber on each actuation thereof is adjustable by means of a variable lost motion coupling associated with the connection means between said first displaceable member and the second displaceable member, variation of the respective lost motion coupling effecting an adjustment to the effective stroke of the respective connection means.
2. A pump as claimed in Claim 1, wherein said first displaceable member is a piston, said second displaceable member is an operating diaphragm, and the connection means includes piston rod means coupled with both displaceable members.
3. A pump as claimed in Claim 1, wherein the fluid actuated switching means is a spool valve or a slide valve which is actuated under fluid control by the pilot switching means, the condition of said pilot switching means controlling the application of pilot operating fluid from said pilot switching means to said fluid actuated switching means and thereby the selection of which of said first and second operating chambers is supplied with operating fluid.
4. A pump as claimed in Claim 1, wherein said pilot switching means is a spool or slide valve arranged to control by fluid control the fluid actuated switching means and is itself mechanically actuated to change state at each end of each stroke of the reciprocating connection means by means of actuating stops associated with the reciprocating connection means.
5. A pump as claimed in Claim 1, wherein said dosing chamber is arranged within a dosing head and said first and second chambers are defined by an operating head.
6. A pump as claimed in Claim 5, which is provided with a single dosing head.
7. A pump as claimed in Claim 5, which is provided with a second dosing head itself having a second connection means operatively connected between a displaceable member associated with a respective second dosing chamber in said second dosing head and said second displaceable member associated with the operating chambers, a second variable lost motion coupling being associated with said second connection means and adapted to function similarly to said first connection means, whereby the pump is capable of metering liquid additive via each of the two dosing heads.
8. A pump as claimed in Claim 1 or Claim 7, wherein the or each lost motion coupling has calibration means giving a visual indication of the dosing rate of the dosing chamber for different settings of the respective lost motion coupling.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08228318A GB2128264B (en) | 1982-10-04 | 1982-10-04 | A pump for supplying a liquid additive to a flow of liquid |
| GB8228318 | 1982-10-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1224671A true CA1224671A (en) | 1987-07-28 |
Family
ID=10533370
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000438330A Expired CA1224671A (en) | 1982-10-04 | 1983-10-04 | Pump for supplying a liquid additive to a flow of liquid |
Country Status (7)
| Country | Link |
|---|---|
| AU (1) | AU557420B2 (en) |
| CA (1) | CA1224671A (en) |
| DE (2) | DE3335610A1 (en) |
| FR (1) | FR2533974A1 (en) |
| GB (1) | GB2128264B (en) |
| HK (1) | HK11887A (en) |
| NZ (1) | NZ205857A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19638083A1 (en) * | 1996-09-19 | 1998-03-26 | Karl Eickmann | Piston sensors for high pressure equipment |
| WO2005045244A1 (en) * | 2003-11-07 | 2005-05-19 | Urrutia Stephane | Hydraulic motor having bellows, and metering pump comprising said motor |
| FR2862105B1 (en) * | 2003-11-07 | 2006-02-24 | Stephane Urrutia | HYDRAULIC MOTOR WITH BELLOWS AND PUMP COMPRISING THE SAME |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB567144A (en) * | 1943-10-04 | 1945-01-30 | Lee Howl & Company Ltd | Improvements relating to reciprocating pumps |
| GB1014571A (en) * | 1964-06-01 | 1965-12-31 | Haskel Eng & Supply Co | Improvements relating to gas-driven liquid pumps |
| US3669572A (en) * | 1970-06-08 | 1972-06-13 | William R King | Constant flow pumping system |
| DE2626954C2 (en) * | 1976-06-16 | 1985-04-11 | Schmidt, Kranz & Co Gmbh, Zweigniederlassung Maschinenbau, 3421 Zorge | Control slide arrangement for a hydraulic pump driven by compressed air |
-
1982
- 1982-10-04 GB GB08228318A patent/GB2128264B/en not_active Expired
-
1983
- 1983-09-30 AU AU19826/83A patent/AU557420B2/en not_active Ceased
- 1983-09-30 DE DE19833335610 patent/DE3335610A1/en not_active Withdrawn
- 1983-09-30 DE DE8328179U patent/DE8328179U1/en not_active Expired
- 1983-09-30 FR FR8315615A patent/FR2533974A1/en active Granted
- 1983-10-04 NZ NZ205857A patent/NZ205857A/en unknown
- 1983-10-04 CA CA000438330A patent/CA1224671A/en not_active Expired
-
1987
- 1987-02-05 HK HK118/87A patent/HK11887A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| FR2533974B3 (en) | 1985-02-08 |
| HK11887A (en) | 1987-02-13 |
| FR2533974A1 (en) | 1984-04-06 |
| NZ205857A (en) | 1986-02-21 |
| DE8328179U1 (en) | 1986-07-10 |
| GB2128264B (en) | 1986-03-05 |
| AU557420B2 (en) | 1986-12-18 |
| AU1982683A (en) | 1984-04-12 |
| DE3335610A1 (en) | 1984-04-05 |
| GB2128264A (en) | 1984-04-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |