US1750634A - Pulsator for milking machines - Google Patents

Description

March 18, 1930.

PuLsA'roR Fon Mmmm MACHINES Filed lay 3. 192B 2 Sheets-Sheet 2 E. A. FORYSBERG 1,750,634 v j ...Patented y UNITED STATES PATENT oFF-ICE 'man Aueftrs'i` nonsense, or STOCKHOLM, SWEDEN, AssIeNon 'ro THE DE LAvAL i snrAnA'ron conrANY, oiel NEW Yonx, N. Y., A conroiwrioir or Naw .Imm

rULsA'ToB son. mLxING MACHINES 'Application aiealay a, 192s, serial No. 274,803, mi inl sweden November 4, ipa?.

The object of this invention. is to provide a milking machine 'pulsator ada ted to havev a constant ulsation -speed an maximum working reliability. Constructions intended to accomplishthese purposes are known and one devised b me and set forth in an app'lication Serial lo. 259,875 filed by me in the United States Patent Otiice March 7, 1928,

and in Sweden a year earlier is 'effective to so regulate the s ed and is reliablyoperative under norma worlng conditions. i Under unfavorable working conditions, however disturbances may occur, mainly because sma. quantities'of moist air may enter the brake cylinder and `condense in the overow channel. While the present invention embodesthe basic conception of the earlier application, it is an improvement thereon inv that it avoids an construction which can 've riseto the a t has also additional advantages which will be clear from the following description. y

Several different embodiments of the invention are shown in the drawings, in

, as whi'ch- Fig. 1 is a longitudinal sectional view of a neumatic milking machine pulsator emybo ing my invention.

ig. 2 is a similar. view of' part of a modi- ,Io fied pulsator. Y

Fig. 3 is a side elevation showing a modi- V fedconnection between theworking iston or diaphragm and the valve for regulating ig. 4 is a view, similar to Fig. 3 of `another modi cation.

Fig. 5 isa side elevation of a part of a pulsator modified by thesubstitution of a dif- 40 ferent type of pneumatic braking device.

Referring first to the construction shown in Fig. 1: V i In Fig. 1, A is the operating cylinder in which is arranged a working iston, which 5 in this construction takes the orm of a dia- -any other suitable ve mentioned condition.

hragm` or membrane T, which forms one exible Wall of'a chambersU. Chamber U 4tween the chambers the pneumatic pulsations to the milking' phragm or membrane B, which can be made of leather, caoutchouc, corrugated metal, or

material. 'The-.chambers C and D on opposite sides of membrane B are, by means of channelsE and F, connected to a valve chest G in which a valve H moves. Valve chest G is, by way of example, connected with a source'of vacuum through a connection' I. Tomembrane B is fixed a rod J acting on Valve H b means of' across piece K and stops M and providedon valve rod L. To the valve runs a channel 0, which connects with the atmos here. f v Rod J is also connecte to a pistonfP,-'which moves in a cylinder R, whose inner end is connected, through a passage Q, with the vac# uuni system.' Between its ends cylinder R has anozzle S, to which is connectible a tube S adapted for connection tothe teat cups either irectlyior through a secondary pulsator, which in known manner effects the distribution of air in the teat cups.

Rod J is` also connected to another dia# communicates with a chamberX through a narrow, preferably regulable liole 'V in a wall Y separating the -two chambers. Rod' J passes through wall Y and is at itsend providedwith recesses Z and near membrane- T with recesses W, so that, at the end positions of the rod J, a free assage is obtained beand X.

`The pulsator works in the following way.

In Fig. 1, the parts Aare shown in the posi# tion they occupy at. that moment when the' stroke to the left is just completed. Cross piece K hasv come into contact with stop M and has moved slide valve H over to the left side. Thereby chamber D has been connected with vacuum through channel F, valve chest G and connection I; while chamber C hasbeen connected with atmosphere through channels E and O. By reason of the difference in pressure between the chambers C and 90 ings. The

D, membrane B and rodJ are now moved to the right. During the first part of the stroke, the movement takesl place rather easily, as air can ass rather freely through paratively. short part o the stroke, the re-V cessed end of rod J moves beyond Wall Y and rod J tightens more or less completely' against wall Y. A certain compression of the air in chamber U now takes place, and the movement cannot now proceed more rapidly than is permitted by the restricted flow of air from chamber U to chamber X through the small holes V. lIn this manner the speed of movement is regulated. When the stroke to the right is nearly completed, recesses W reach Wall Y, whereby a comparatively free passage for air is again opened between the chambers U and X. Equalization in pressure in the two chambers now takes place and piston J completes its stroke comparatively rapidly. As piston rod J nears the end of its stroke to the right, cross piece K engages projection N and, as rod J completes its movement, moves slide valve H to the ri ht hand end position opposite that shown in t e drawparts B, J and T now move to the left, the oI eration bein similar to that which occurre I in the descri ed movement of these parts to the right.

Approximately or exactly when rod J passes its middle position, piston P also passes connection S, thereby causing the lat'- ter to shift its connection from vacuum to atmospheric pressure, or lvice versa. In this way, pulsations in the teat cups or in the secondarypulsator are generated.

A feature which especially characterizes the present invention is that chambers U andl X together form an entirely closed system, and therefore'impurities cannot, in any circumstances, penetrate from outside and obstruct the flow of air through opening V. For this purpose a single-acting membrane is used in the braking device, whereby no movable tightening against the outer atmosphere around rod J is necessary.

In the embodiment shown in the accompanying drawing there exists, however, such a tightening around rod J at the operating cylinder. This is of minor importance, since,

without considerable complication of the construction, it is in any case not possible wholly to-hinder moist air and the likefrom penetrating into the operatin cylinder, and,

moreover, this does not su stantially affect the efficiency of the pulsator.

However, to guard against the possibility that a certain friction may occur by reason of tightening around the rod J which, in unfavorable circumstances,could cause irregularities in the operation, a single-acting operating cylinder, of which that shown in Fig. 2 is an example, `may be used. In this construction, membrane 10 is normally kept extended by a spring 1l and is brou ht to the opposite end position under the in uence of a vacuum in the chamber, 12. Other details may be similar vto those in Fig. l, but the cylinder R with attached parts should be located between the operating and brake cylinders.

A certain diiiiculty may arise due to the known qualityof membranes to permit only a rather limited length ofstroke compared with their dimensions. Thus, it may be dificult, at least withcertain dimensions, to give the recesses Z and W suiicient dimensions to insure a rapid equalization in -pressure between the chambers U and X at the end positions of the stroke. This may be avoided by arranging, in the wall Y, a special valve which is opened at the end positions by the rod J. But another and greater inconvenience is that iston P, and especially slide valve H, in or er to function in a reliable way, 'may require a movement of greater length than a membra'ne T of suitable diameter will permit. In such a case it is practicable to arrange gearing between rod J vand piston P and valve rod L which Will increase the amplitude. Such a gearing can be of any known kind, for instance, la lever or a toothed wheel. Figs. 3 and 4 show schematically two'` dierent embodiments` of such a device. s

In Fig. 3, rod J is connected with piston P by means of a lever 20 pivoted at 21. The ends of the le'ver 20 are forked to embrace pins 22 on rod J and pins 23 on piston rod P. The end of lever 20 works against the stops M and N on slide valve rod L. The interior of the cylinder R maybe connected with the vacuum system through the connection 24.

In the embodiment shown in Fig. 4, the rod J is provided with a rack engagin with a pinion 30, whichis connected to a t(larger toothed wheel 31. which in turn engages a rack 32 on the piston rod of 'piston P, the piston rod carrying the cross piece K adapted to engage stops M and N.

In order to increase the mobility of one or both membranes B and T, it is practicable to make one or both of them in the form of bellows, as shown in Fig. 5. This device is especially suitable as a substitute for membrane T, because it may be constructed of such dimensions as to be responsive to small pressure differences. In such Ya case, however, the volume of -air rushing to and from the chamber 'U is comparatively large, and therefore the chamber X must be given ample dimensions if strong differences in the prepssure are not to occur. It is therefore desirable in this case to provide chamber X with a movable wall against the exterior, so that the volume of this chamber can change without the pressure therein deviating from the atmospheric pressure to any noteworthy degree. If it is desired to use the simple form p l of membrane in the operating cylinder, which is practicable because of the comparatively great difference in pressure which pre'- vails in it, which difference in lan ordinary' embodiment would amount to about 0.5 atmosphere, the amplitude will, of course, become rather limited. In such a case it is practicable to arrange, between'the operating and brake cylinders, a" gearing which increases the movement.

Fig. 5 shows schematically such a device. 40 is the iston rod extending from the operating cylinder, which may be provided with a double or sin le-acting membrane or piston. The piston ro is-provided with a rack engaging a pinion 41, on whose shaft is a toothed wheel 42. This toothed wheel enga es a rack on a rod 43, which carries the end head 44 of a bellows-membrane 45. An expansible and contractible chamber 48 is formed by a flexible vwall 47 secured to the other end head 46v (sleeved on rod 43) of the bellows-membrane.

Having now fully described my invention,

what'I claim and desire to protect by Letters Patent is: v p

1. VA milkin machine pulsator comprising a pneumatical y operable working member, a neumatic pulsation tube, means controlled Eysaid member to effect pneumatic pulsations in said tube, anda fluid braking device connected with, operable by, and controlling the speed of, said working member; said braking device com rising walls forming two chambers shutl off rom the atmos here, the exterior wall of one of said cham ers comprising a movable diaphragm, and rts afy fording communication between said chambers.

2. A milking machine pulsator comprising apneumatically o erable working member, a pneumatic pulsationtube, means controlled by said member to eiect neumatic pulsations in said tube, and a lui braking device connected with, operable by, and controlling the speed of, said working member; said braking device comprising walls forming two chambers shut oi from the atmosphere and ports affording communication between-said chambers, the exterior walls or both of said chambers comprising movable diaphragms.

3. A milking machine pulsator comprising a neumatically operable working member, a lvallve adaptedtocentrol the neumatic operation of said workingl meinr, means controlled by said member to actuate the valve, a tube throu h which pneumatic pulsations are transmissigle, a regulating valve, connected with and actuable by said working member,

adapted to effect neumatic pulsations in said tube, and a iluicl' braking'device connected with, operable by, and controllin the speed of said workin member; said bra 'ng device comprising w forming chambers shut oif from the atmosphere and ports affording and means allowing,

communication between said chambers, the exterior wall of one of said chambers com,

machine pulsator comprising 5. A milking machine pulsator comprising a pneumatical y operable working member, a valve adapted to control the neumatic operation of said working member, means controlled by said member to actuate the valve, a tube through which pneumatic pulsations are transmissible, a re ulating valve connected with and actuable said tube, and a braking device connected with, operable by, and controlling the speed of, said working member; said working member and said braking device comprising re- .spectively expansible membranes connected to operate in unison.

6. A milking machine pulsator comprising a pneumat1c pulsation tube, a pulsating dev1ce, means controlled by the pulsating' de-A vice to effect pneumatic pulsations in said tube, and a fluid braking device connected with, operable by, and controlling the speed of the pulsation device; said pulsating device comprising a rigid wall and a diaphragm forming between them a pulsation chamber, the exterior wall of the diaphragm being const-antly open to atmospheric pressure, a valve adapted to vary the absolute air ressure in said chamber, and means actuable y said diaphragm to actuate said valve.

l 7.- A milking machine pulsator comprising a pneumatically operable working member a pneumatic pulsation tube, means controlled by said member to effect pneumatic pulsations in said tube, a rod reciprocable by said working member, a Huid braking device com rising walls forming two chambers into w ich by saidrod and forming one o sai walls, during the movement of said rod and diaphragm, flow of fluid between said chambers at such late the sp said rod extends, and a diaphragm o erable eed of the working member.

8. A mllln'ng machinepulsator comprising 1 a pneumatically operable working member, a pneumatic pulsation tube, means lcontrolled y said member to effect tions in said tube,a rod reci rocable by said working member, a fluid braking device comprising ywalls forming two chambers into y said working mem'- l ber, adapted to effect pneumatic pulsations in rate as to regupneumatic pulsawhich said rod extends, and a diaphragm operable by said rod and forming one of said walls, a. port in the wall separating said chambers allowing restricted flow of fluid, said rod having grooves-adapted to aiord additional fluid communication between said chambers as the rod approaches the ends of its move-` ment.

In testimony of which invention, I have hereunto set my hand, at Stockholm, Sweden, on this 19th day of A ril, 1928.

ERIK AU UST F ORSBERG.

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