NZ243103A - Milking machine pulsator rate adjuster with breather hole in sealing cap - Google Patents

Description

C\ 24 310 PATENTS FORM NO. 5 Fee No. 4: $260.00 PATENTS ACT 1953 ^ _ COMPLETE SPECIFICATION , After Provisional .>■ / •"■fVO No: 243103 ^ Dated: 10 June 1992 , f« ^ I PULSATOR IMPROVEMENTS We NU PULSE NEW ZEALAND a division of Alfa-Laval (NZ) Limited of 82-86 Bandon Street, Hamilton, New Zealand, a New Zealand company hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: 1 24 3 1 03 This invention relates to pulsators for milking plant.

The NU PULSE milking systems pulsator has a pulsation unit mounted on a milking claw, and has been established in the market in New Zealand and overseas for some twenty years.

A major development to the claw was made during the late 1970s when the it was modified by the inclusion of a diaphragm which separated the milk and air portions of the claw. , «*> Figure 1 of the accompanying drawings is an exploded view of the current NU PULSE standard and MOC claw.

The claw comprises a claw bowl split about a flange into upper and lower sections. The lower section incorporates milk inlets and a milk outlet. The upper section incorporates a skirt and a rim which accommodates fixed and moving parts of the pulsator unit. Other main parts of the pulsator unit are a substantially funnel shaped bobbin housing, a 15 complimentary bobbin, a diaphragm, and a cap. The operation of the pulsator is fully described in New Zealand patent specification No. 189104, which description is incorporated herein by way of reference.

The pulsator is generally tuned to give 50 to 55 pulsations per unit with the peg diagram 3-5 providing for pulsation rate adjustment.

Figure 2 of the accompanying drawings is an expanded view of the existing peg diaphragm system which allows for pulsator adjustment.

The peg diaphragm comprises a t-section apertured stem 22, a diaphragm, locating collar 23 which secures the inner parts of the diaphragm 24 with respect to the stem 22 and an adjustment peg 25 and collar 26 which can be 2 ■ 24 3-1 adjusted as described in patent specification No. 189104 to alter the flow rate of air between the pulsator dome and lower sections via the aperture 27 of the stem 22. Whilst this pulsator rate adjustor has performed satisfactorily for many years it is difficult for an untrained person to 5 consistently and accurately set a desired pulsation rate.

It is an object of the present invention to provide an improved pulsation rate adjustor for a pulsator of the kind described.

Further objects and advantages of the present invention will become ft apparent from the ensuing description which is given by way of example. - According to the present invention there is provided a pulsation rate adjuster for a pulsator of the kind described said pulsation rate adjuster including an apertured stem where the aperture in the stem provides an air passage between a pulsator dome and a base of the pulsator, a sealed cap covering an outlet on the dome side of the aperture said cap having a 15 breather hole in the surface of the cap which rests on the upper surface of the stem adjacent the aperture and an irregular recess in the surface of the stem communicable with the aperture, the arrangement and construction being such that rotation of the cap with respect to the stem increases or decreases the leakage of air from the dome to the base via the 20 apertures in the stem and the cap.

Upper regions of the apertured stem are circular and complementary with engaging inner surfaces of the cap and the irregular recess in the upper surface of the stem is cam-shaped.

The pulsation rate adjuster includes sealing means between the engaging 25 inner surfaces of the cap and the complementary surfaces of the stem. 3 243 103 The apertured stem is a T-section member with the head of the stem having the irregular recess and providing a peripheral groove for location of the sealing means.

The apertured stem is supported by a diaphragm which separates the dome and base of the pulsator.

Aspects of the present invention will now be described with reference to the accompanying drawings in which: Figure 3: which is a diagrammatic cross-section of a pulsator rate adjuster in accordance with one possible embodiment of the present invention and Figure 4: is a plan view of the pulsator of Figure 3.

With respect to Figures 3 and 4, the pulsator rate adjuster has a diaphragm stem 22, diaphragm 24 and collar 23 similar to that described in relation to the prior art device (Figure 2). The present invention provides a modified peg generally indicated by arrow 30 and a rotatable sealed cap generally indicated by arrow 31.

The peg 30 includes an apertured stem 32 which is a push fit in the aperture 27 of the stem 22. The stem 32 has an enlarged disc shaped head 33. The disc shaped head 33 is provided with an irregular shaped recess 34 in the upper surface thereof and an O-ring seal 35 in the side walls thereof.

The cap 31 has side flanges 36 which are a tight fit against the sides of the head 33 and seal 35 and is provided with a breather hole 37. The passage of air from the aperture 27 via the breather hole 37 is as indicated by the ^^^^^^,varrow and it is noted that the air passage between the aperture 27 and i/** "'•^ breather hole 37 is via the recess 34 in the surface of the head 33. The cap tU -r.V ^ 20 SEP 1995 '""/t c ■ * »f 4 vs. 243 103 31 can be secured to the head 33 by a U-shaped circlip 38 or such like which passes around stem 22 and locks into lower parts of the sides 36 of the cap 31.

Figure 4 shows the irregular shape of the recess 34. The recess 34 is cam-shaped. The cap 31 which may be moulded in clear plastic can be rotated between two positions one being for "fast" pulsation and the other for "slow" pulsation. In the fast pulsation position FP indicated on Figure 4 the breather hole 37 is fully open to the recess 34 whilst in the slow pulsation position SP only a part of the breather hole 37 is communicates with the recess 34 there being intermediate stages is as indicated.

The outer surface of the cap can be marked to indicate the fast and slow pulsation positions and it is preferred that the cap and stem be moulded from different plastics materials, to reduce binding.

Initial trials with the pulsation rate adjuster have confirmed that it is far more convenient to use than the earlier versions and adjustments of pulsation rate from 30 to 90 pulsations per minute can be quickly and accurately set.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope of the invention as defined in the appended claims.

Claims (5)

243 105 WHAT WF. m.ATM IS:

1. A pulsation rate adjuster for a pulsator of the kind herein described said pulsation rate adjuster including an apertured stem where the aperture in the stem provides an air passage between a pulsator dome and a base of the pulsator, a sealed cap covering an outlet on the dome side of the aperture, said cap having a breather hole in the surface of the cap which rests oil the upper surface of the stem communicable with the aperture, the arrangement and construction being such that rotation of the cap with respect to the stem increases or decreases the leakage of air from the dome to the base via the apertures in the stem and the cap.

2. A pulsation rate adjuster as claimed in claim 1 wherein upper regions of the apertured stem are circular and complementary with engaging inner surfaces of the cap and an irregular recess is provided in the upper surface of the stem which is cam-shaped.

3. A pulsation rate adjuster as claimed in claim 2 which includes sealing means between the engaging inner surfaces of the cap and the complementary surfaces of the stem.

4. A pulsation rate adjuster as claimed in claim 3 wherein the apertured stem is a T-section member with the head of the stem having the irregular recess and providing a peripheral groove for location of the sealing means.

5. A pulsator including a pulsation rate adjuster as claimed in any one of claims 1 to 5 wherein the apertured stem is supported by a diaphragm which separates the dome and base of the puls^^t^ 6 ^ ^ » oS'1. 6 \ 2° SEP 1995 -I WHCInJUna*' 24 31 A pulsation rate adjuster substantially as hereindescribed with reference to the accompanying figures 3 and 4. NU PULSE NEW ZEALAND A DIVISION OF ALFA-LAVAL (NZ) LIMITED by their Attorneys