GB2094126A - Vacuum pulsator valves - Google Patents

Description

SPECIFICATION Vacuum pulsator valves The invention relates to vacuum operated pulsator valves for use with milking machines adapted to be wholly automatic in use.

To assist in the understanding of the present invention the various types of pulsators commonly used will defined.

1. MASTER AND SLAVE PULSATOR 2. AUTOMATIC PULSATOR 3. RELAY PULSATOR 4. PULSATORTYPES : REVERSING. NON REVERSING.

Master and Slave pulsation indicates that all bail pulsators receive and are driven by the actuating vacuum/air pulse generally supplie from a mechanical master pulsator driven from the vacuum pump.

In this system the air demand is balanced by having the pulsators operating in opposing banks of units so that when one bank is on vacuum the other is on air. This is accomplished by the use of a reversing pulsator, or pulsators installed at intervals, or by direct linkage from the master pulsator.

Automatic puisators do not require a master.

Initially they are basically designed to produce, at requisite mercury levels a defined pulse, the rate or speed of which is either fixed or adjustable by controlling the volume interchange to a timing chamber of the vacuum/air phases produced by the pulsator. Present type automatic pulsators have a less stabilising effect on air line vacuum as having no master control, all pulsators operate more or less at random. Broadly automatic pulsators fall into two types: (i) Those pulsators designed to produce purely pneumatically at requisite mercury levels a defined ratio of pulsation of vacuum to atmospheric pressure, the rate or speed of the said pulsation being regulated by the controlled interchange to a timing chamber, either by fixed jet or adjustable valvular means of the vacuum/air phases produced by pulsa- tor action.

(ii) Those developed on the so-called windscreen wiper principle combining both pneumatic and mechanical features. These are based on pneumatically operated opposing diaphragms which alternatively and mechanically actuate a spring loaded plastic slide switch-over arrangement which in turn controls the admittance of vacuum or atmosphere to the opposing diaphragms and also to the slide controlled ports giving access to and the resultant pulse to the treat cups.

Both in construction and performance these pulsators are more or less stereotyped and none are capable of performing other than the fixed role in milking machine pulsation for which they were designed.

Relay pulsation on milking machines is defined as where the first bail pulsator receives its actuating pulse direct from a"Master"and then in turn relays the pulse received to the next pulsator and so on.

This means that the vacuum/air phases"ripple" along the air-line thus stabilising the vacuum variation in the line to a greater extent than in the balance effect of Master and Slave pulsation.

Pulsatortypes ; Reversing and non-reversing.

The reversing pulsator is so called because it delivers the opposite pulse to that received, i. e: upon receiving an air pulse to its actuating chamber it delivers a vacuum pulse to the teat cups and in relay pulsation-also to the next pulsator and vice versa.

The non-reversing pulsator upon receiving an air pulse, delivers an air pulse and vice verse.

In all known pneumatic relay pulsators controlled by an automatic master the passing of pulsation phases one to the other has only been effectively accomplished when the pulses passed were of an equal ratio. In the circumstances where a master or a relay pulsator produces an operating pulse where the vacuum phase is greater than that of atomospheric pressure such as vacuum/air ratio of 60 : 40, then this pulse would, if passed directly to the actuating chamber of the next pulsator, produce to the connected teat cups of that pulsator the reversed vacuum/air ratio of 40: 60.

There is no known milking machine valve capable of correcting this effect and enable in such pulsation the passing one to the other of any desired constant ratio.

This invention relates to both reversing and nonreversing type vacuum operated pulsator valves for use with milking machines adapted to be wholly automatic in use. Preferably the invention will be described with reference to a reversing type pulsator i. e: a pulsator which on receiving an air pulse to its timing or to its actuating chamber, produces an ensuing vacuum pulse to its attached teat cups and vice versa.

It is the principal objective of the invention to provide a pulsator valve for milking machines which is readily adjustable as to rate of pulsation and also as to the ratio of pulsation of vacuum to both atmospheric and compressed air pressure as required.

It is also an objective of the invention to provide: 1. a master or control pulsator for operating a plurality of slave pulsators ; 2. a relay from pulsator to pulsator under master control reversible or non-reversible ; 3. as a master and slave combination; or 4. as an automatic unit operating as a milking medium directto teat cups.

5. A pulsator with externally mounted control valves and a timing chamber with external access to the vacuum/air pulses received. The valves are flexibly connected to timing chambers.

It is also an objective of the invention to provide: a pulsator valve also having incorporated, or may have as a separate attachable unit, readily adjustable valvular means enabling it at the same time, or independently, to be used as a master pulsator for the transmitting or relaying of any desired pulsation ratio; a relay pulsator valve having incorporated or attached similar adjustable valvular means as in the preceding paragraph of readily adjusting in step or out-of-step pulsation ratios to any desired constant ratio; a pulsator valve as in the preceding paragraph also designed to act as a versatile reversing or balancing pulsator between those opposing banks of pulsators that are so disposed in master and slave pulsation operated miling machines in orderto balance air demand; a highly efficient slave pulsator suitable for either mechanical or automatic master control ; the pulsator valve as in preceding paragraphs eminently suitable for use with compressed air in lieu of atmospheric air as the pressure medium to the teat cups; valvular means as described (see Figure 4) which may be used independently as a means of converting other types of slave or relay pulsators to any desired ratio of pulsation.

According to the present invention there is provided a vacuum pulsator comprising a body for housing a pair of valves sealingly mounted within the body, one valve being moved alternately to the othervalve between two positions to control a bleed means, said bleed means communicating with the other valve for alternately applying vacuum and pressure to said othervalve, said bleed means including adjustable means controlling the ratio of the pulsator cycle and thereby controlling the length of time said valve is subjected to vacuum or pressure.

Conveniently the adjustable means is a needle valve associated with the bleed means controlling the volume of fluid to said other diaphragm.

According to a further aspect of the invention adjustable additional air or vacuum bleed means are provided operable to varythe rate orfrequency of the pulsator cycle viz. by varying the rate of alternation of said valves.

The invention will be described in greater detail having reference to the accompanying drawings in which: Figure 1 is a section view of a master pulsator taken on line II-II of Figure 2.

Figure 2 is a plan view of Figure 1.

Figure 3 is a sectional view of a relay pulsator taken on line lil-lil of Figure 7.

Figure 4 is a section view taken on line IV-IV of Figure 2.

Figure 5 is a section view taken on line V-V of Figure 2.

Figure 6 is a sectional view of ratio adjusting mechanism taken on line VII-VII of Figure 7.

Figure 7 is a plan view of a relay pulsator.

Figure 8 is a section view of the relay pulsator taken on line VIII-VIII of Figure 7.

Figure 9 is a section view of a pressure member taken on line IX-IX of Figure 10.

Figure 10 is a plan view of a pressure member.

Figures l la, l lb & 11c graphs graphs different pulse cycles obtainable with the pulsator of the present invention.

The timing chamber 1, is cylindrical in shape and has an external nozzle 29, giving connection to the vacuum/air phases controlled by the rate adjusting needle valve 19, and the ratio adjusting needle valve 21.

Thefabricated housing includesthetiming chamber 1, a body 2, and base 3, having a permanent connection to vacuum 4, and a connection 5, to the milking machine teat cups.

A diaphragm 6, located in the section between the chamber 1 and body 2 and capable of being sealed by the timing chamber 1. An annular seat 7, and a pressure member 8, is interposed in the chamber between the connection to vacuum 4, and the connection to teat cups 5, and is slidable in the guide 9. The pressure member 8, is arranged to be in contact with both the diaphragm 6, and the central seating arrangement 7.

The lower section of the pressure member 8 also acts as a valve member in contactwith a valve diaphragm 10 located in the base of the pulsator 3 functioning to operate immediatelythe pressure member 8 is moved down under atmospheric pressure on the diaphragm 6 so as to prevent direct passage of atmospheric airto the vacuum connection during the changing phases of the pulsator from air, or from vacuum to the teat cups. The valve diaphragm 10 also co-acts with the seat 11 located in the base 3 for admitting atmospheric air to the teat cups through connection 5.

The base 3 is circular in shape and has four holes 12 arranged centrally to allow admittance of atmospheric air to the pulsator. Provision is made 13 for attachment of a suitable air filter. Alternatively the air admission holes 12 may be plugged off or omitted and replaced by a suitable connection giving the pulsator access to compressed air.

Around the holes 12 is arranged a ring or seat 11 and adjacent there-to are arranged metering holes 14 enabling atmospheric air to pass to the teat cups through connection 5. Sitting across the seat 11 is a valve diaphragm 10 held in place by a suitably fixed retaining plate 15 which has a central aperture 16 extending just clear of the outer periphery of the seat 11 allowing access to the contacting valve head of the pressure medium 8. Adjacent to the aperture 16 the retaining plate has a circular recess 17. The object of this recess is to allow the valve diaphragm to have minimal or no clearance across the seat 11 so that the entry of atmospheric air to the pulsator under pulsation is only possible on the air phase to cups, thus creating a positive and leak proof pulsator under all conditions of operation.

When a vacuum phase pertains to the pulsator the recess 17 operates in conjunction with the projection 8b and the recess 8c of the pressure member 8 to give clearance across the seat 11, thus allowing atmospheric air to pass to the teat cups.

The pressure member 8 is of particular shape. The guide stem 8a being fiuted or grooved to both reduce friction and give free passage of atmospheric air via the fluted air passages 8d from teat cups to permanent vacuum.

The lower section which operates in permanent contact with the valve diaphragm 10 is stepped in shape having a circular projection 8b and a circular recess 8c the action of which is as follows : 1. On atmosphere applied across the diaphragm 6 the resultant initial downward movement of the pressure member 8 causes the small projection 8b acting centrally on the valve diaphragm 10 to immediately close off atmospheric air across the seat 11. The further downward movement continuing until stopped by the recess 8c acting across the seat 11 thus providing accurate opening of the seat 7 to permanent vacuum.

2. On vacuum applied across the diaphragm 6 atmospheric air entering through the holes 12 against the valve diaphragm 10 forces the pressure member 8 upwards to instantly close off permanent vacuum at the seat 7 and at the same time forces and distorts the valve diaphragm 10 around the projection 8b into the recess 8c and across into the recess 17 of the retaining plate 15 thus giving full clearance above the seat 11 and allowing atmospheric or compressed air to pass to the teat cups via the air metering holes 14 and connection to teat cups 5.

The graph in Figure 11 a shows a standard pulse curve with curve 50a showing the vacuum phase and 51 a in pressure phase.

Referring to Figure 5 a housing 18 is externally and vertically attached to the body 2 preferably having a rate adjusting needle valve 19 its seat 20 a ratio adjusting needle valve 21 and its seat 22.

The rate adjusting needle valve 19 is connected via the duct 23, channel 24 and the duct 25 to the vacuum/air phases of the pulsator and thence via the needle valve 19, the common chamber 26 nozzle 27, flexible tube 28 to the nozzle 29 directly connected to the timing chamber 1.

The function of the rate adjusting needle valve is to control the rate at which air passes to and from the timing chamber. The greater the opening the faster the pulsation rate. The smaller the opening the slowerthe pulsation rate.

The ratio adjusting needle valve 21 (Figure 5) is connected via the chamber 30, the duct 31, the common chamber 26 and thence via the nozzles 27 and 29 to the timing chamber 1. It also has connection via the duct 32 and channel 33 to permanent vacuum pertaining at the duct 34 or to atmospheric via the port 35 either of which may be alternatively plugged off by the removable plug 36 according to the particular ratio required. If a longer vacuum phase is required the removable plug 36 preventing the admission of atmospheric air through the port 35 is removed and inserted into the channel 34 connecting permanent vacuum via the ratio adjusting needle valve 21 to the timing chamber 1. This increases the length of the vacuum cycle whereas connection to permanent vacuum lengthens the pressure cycle of the pulsator.

The ratio needle valve is now opened to admit sufficient atmospheric air to the timing chamber 1 to give the required longer vacuum phase to the teat cups.

Figure 11c shows the longer vacuum phase 50c as againstthe pressure phase 51 c.

This is engendered by the extra time the vacuum bleed via the rate adjusting needle valve 19, the nozzles 27 & 29 to the timing chamber 1 takes to remove sufficient air to enable requisite vacuum to pertain in the timing chamber to facilitate the following airto cups phase.

To shorten the vacuum to cups phase atmospheric air is shut off by reversing the plug 36. The open duct 34 now gives an added vacuum bleed via the channel 33, duct 32, the adjusted ratio needle valve 21, chamber 30, duct 31, common chamber 26, nozzles 27 & 29, to the timing chamber 1. This in conjunction with the vacuum pertaining through the rate adjusting needle valve 19 to the timing chamber 1 causes vacuum to attain quickly in the timing chamber with resultant longer air phase to the teat cups.

Figure 11 b shows the short vacuum phase 50b and the long vacuum phase 51 b.

With the plug 36 inserted into the port 35 and the ratio adjusting needle valve 21 closed, the standard ratio of the pulsator pertains.

When it is required that the pulsator as described, also or independently, act as a master pulsator transmitting or relaying a specific ratio of pulsation, the following valvular relay ratio adjustment means as shown in Figure 6 are also suitably attached to the body 2.

The valve housing 37 is preferably oblong in shape and is constructed with two main air passages 38 and 39. Passage 38 incorporates preferably a ball valve 40 and its seat 41. The upward movement of the ball is contained and controlled bythe adjustable coned retaining screw42.

Passage 39 incorporates and is controlled by preferably a needle valve 43 and its seat 44. Both passages are commonly interconnected via the channels 45 and 46 to both the vacuum and atmospheric air phases to the teat cups of its attached pulsator through the connection 47 and to the connecting nozzle 48 operating to the actuation chamber to the next and driven pulsator.

The function of the valve when used in conjunction as a master or as a fixed component of a relay pulsator valve is to correct any ratio of vacuum to atmospheric air inherent to it, to that ratio necessary for the required operation of the relay or slave pulsators subject to it.

When used in fixed relationship as a relay pulsator subject to master control it may also be used preferably as a driving unittransmitting a corrected pulse to the next pulsator or as a driven unit correcting and operating to the pulse received. In the latter usage the valve has no connection to the vacuum and atmospheric air phases of the pulsator to which it is attached. These are received from a suitable connection on the previous relaying pulsator and connected directly to an external nozzle on the valve housing 37 giving access to the passage 38. The pulse corrected by the valve passes via the nozzle 48 to the actuating chamber of its attached pulsator.

Description of relay pulsator valve Figures3, 4,6,7 & 8.

The construction of the relay valve is identical to that of the automatic valve except that the rate and ratio valve is omitted, the timing chamber 1 is replaced by the pulsator cap 50 which has preferably a nozzle connection 49 giving access to the actuating chamber 51 and the relay/ratio adjustment valve 37a is added as a combined entity.

It will be appreciated that the relay/ratio valve 37a may be added to any pulsator of the same general type.

Referring to Figures 3 & 4 when atmospheric air pertains to the valve via the connection 47 air flows through passage 38 and via the ball valve 40 lifted thereby, common channel 46 and via channel 45, the needle valve 43, passage 39, chamber 46, through the connecting nozzle 48 to the nozzle 49 giving access through the pulsator cap 50 to the actuating chamber 51 of the driven pulsator to provide free and rapid action of the diaphragm 6. The airflow or pulse thus passed causes a resultant instant vacuum pulse to the teat cups of the driven pulsator.

Conversely, when vacuum pertains to the valve, air being withdrawn immediately closes the ball valve 40 thus compelling all airto pass via passage 39, the adjusting needle valve 43, channel 45, passage 38 to the connection to vacuum 47. Vacuum now pertaining to the actuating chamber of the driven pulsator causes atmosphere to pertain to the attached teat cups.

Adjustment To lengthen the vacuum to teat cups phase the withdrawal of air is restricted by closing the ratio needle valve 43 thus prolonging the air phase to the actuating chamber to the desired ratio.

To shorten the vacuum to teat cups phase the ratio needle valve is opened thus accelerating the withdrawal of airfrom the actuating chamber.

Description of slave pulsator The construction of the slave pulsator is identical to the relay pulsator except that the relay ratio adjustment valve is omitted.

With the trend to more rapid rates of pulsation combined with increased and increasing vacuum to atmospheric air ratios to promote faster milking of the herd, the time factor in pulsation for the introduction of atmospheric air giving pressure to the teat cups has become progressively shorter and less conductive to cow comfort and well being.

The application of compressed airto pulsators while it would accelerate and increase the pressure cycle, necessitates a pulsator essentially capable of having the ratio of pulsation adjustable to both the air pressure used and the rate of pulsation required otherwise advantage gained could be largely negatived by pressure induced ratio imbalance.

Claims (10)

1. A vacuum pulsator comprising a body for housing a pair of valves sealingly mounted within the body, one valve being moved alternately to the other valve between two positions to control a bleed means, said bleed means communicating with the other valve for alternately applying vacuum and fluid pressure to said other valve, said bleed means including adjustable means controlling the ratio of time in which said othervalve is subjected to vacuum orfluid pressure.

2. Avacuum pulsatorasclaimed in Claim 1 in which said adjustable means is a needle valve associated with the bleed means controlling the volume of fluid flowing to said other valve.

3. Avacuum pulsatorcomprising a body for housing a paid of diaphragms sealingly mounted with the body, one diaphragm being moved alternately to the other diaphragm between two positions to control a bleed means, said bleed means communicating with the other diaphragm for alternately applying vacuum and fluid pressure to said other diaphragm, said bleed means including adjustable means controlling the ratio of time in which said other diaphragm is subjected to vacuum orfluid pressure.

4. Avaccum pulsator as claimed in claim 4 in which air and/or vacuum bleed means are provided communicating between said diaphragms acting to control the frequency or rate of alternation of the pulsator cycle.

5. A vacuum pulsator as claimed in Claim 3 in which the bleed means is connected to either a permanent vacuum source or to atmosphere by passages selectively blocked by plug means thereby varying the length of time said other diaphragm is subjected to atmosphere or vacuum.

6. A vacuum pulsator as claimed in any preceding claim in which said pulsator is used as a master pulsator relaying pulsations to additional interconnected vacuum pulsators, said connection being via a said time ratio adjustment bleed means to allow correction of pulsation phases to each pulsator.

7. A vacuum pulsator as claimed in any preceding claim including a pressure member interposed and slidably mounted between said diaphragms to move in response to pressures acting upon said diaphragms, said other diaphragms working in conjunction with a valve seat to control ingress of atmosphere past said seat, said pressure member including a projection engageable with said other diaphragm to achieve a sharp cut-off across said valve seat.

8. A vacuum pulsator as claimed in any preceding claim in which the said one valve is positioned in a timing chamber the bleed means communicating with said chamber via an externally accessible flexible pipe coupling.

9. A vacuum pulsator as claimed in any preceding claim in which the fluid is compressed air.

10. Avacuumpulsatorsubstantiallyasherein described when having reference to the accompanying drawings.