Milk tap device for milking machine

A milking machine tap assembly for connecting a teat cup unit with a vacuum pipe and a milk pipe extending within the vacuum pipe. A tap box unit is provided which has a housing with a window opening in its side wall, and two axially aligned connecting tubes at opposite ends of the housing to connect with confronting sections of the vacuum pipe. A tubular milk tap body within the housing has its ends arranged to connect with confronting sections of the milk pipe, the tap body also having a first port through its side wall to enable the teat cup unit to communicate with the milk pipe through the tap body. A tap frame is fixed to the housing over the window opening to position the first port. An air packing is mounted on the frame and cooperates therewith to form a second port which enables the teat cup unit to communicate with the vacuum pipe through the housing interior. A gate is slidably mounted to the frame for simultaneously closing the first and second ports.

BACKGROUND OF THE INVENTION 
The present invention relates generally to a milk tap assembly in a milking 
machine system, and particularly to a milk tap assembly for joining a teat 
cup unit to a system wherein a milk pipe is provided within a vacuum pipe. 
Milking machine system of conventional design are constructed in such a way 
that milk and vacuum pipes are positioned about 1.5 meters above and 
parallel to the floor. This arrangement was intended mainly to protect 
milk pipes made of the glass from being kicked and destroyed by cows. 
However, with such a difference in height between the milk pipe and a teat 
cup unit affixed to the cow, vacuum pressure in milk lines associated with 
the teat cup unit changes as the milking operation proceeds. Thus, the 
vaccum pressure applied to the cow's teats changes every time the milk is 
sucked, and causes congestion about the teats or mastitides from the 
strong stimuli applied upon the lactic glandular cells. The conventional 
milk machine system generally is arranged as shown in FIG. 8 of the 
accompanying drawing, wherein a milk pipe 1 and a vaccum pipe 2 are 
positioned parallel to the floor and provided with a given number of tap 
boxes 3. A milk tube 4 is affixed to the box 3 at one end, and is 
connected at its other end with a milk claw 5 having a number of teat cups 
6. A pulsator 7 is fixed to the tap box 3, and is interconnected with the 
vacuum pipe 2. Pulsator 7 and teat cup 6 are joined with a vacuum tube 8. 
In accordance with this construction, the milk tube 4 extends for a height 
H between the milk claw 5 of the teat cup 6 and the milk pipe 1 which 
transfers the milk. Thus, milk is not sucked immediately after attachment 
of the teat cups 6 to the teats. The vacuum in the milk pipe 1 works 
directly upon the teats via the milk tube 4 and the milk claw 5. When milk 
starts to flow out of the teats, passes through the milk claw 5 and begins 
to fill the milk tube 4, there arises a loss in vacuum when the milk tube 
4 becomes completely filled with milk because of the height H of the tube. 
This acts to decrease the vacuum applied upon the teats of the cows. When 
the milking operation is over and no more milk is drawn into the teat 
cups, the vacuum then works on the teats in the same manner as when the 
operation began. Thus, the vacuum working on the teats changes from high 
to low and then again to high levels. A bleeder-hole is provided in the 
milk claw 5 to facilitate a smooth flow of milk by allowing air to enter 
into the milk tube 4 to prevent the tube from becoming overly full with 
milk. In the case where the height from the milk calw 5 to the milk pipe 1 
is 1.5 meters, the vacuum within the milk pipe 1 is usually 380 mm Hg. 
However, when the milk tube 4 is filled with milk, there will be a loss of 
about 110 mm Hg so that the vacuum working on the teats decreases to 270 
mm Hg. In this manner, the vacuum changes from 380 to 270, and back to 380 
mm Hg during the milking operation. If these variations continue, the area 
around the teats will become congested and the orifice of the lactic canal 
will project and turn outwardly, thereby increasing susceptibility to 
germs and to sicknesses. 
An object of the present invention is to obviate the above defects in the 
prior milking machines and to prevent injuries to the teats of milking 
cows. 
In accordance with the present invention, a milking machine tap arrangement 
for connecting a teat cup unit with a milk pipe and a vacuum pipe 
comprises a tap box unit including a housing having a window opening in an 
axially extending side wall, and two axially aligned connecting tubes 
extending from opposite ends of the housing for providing air tight 
connections with axially spaced sections of a vacuum pipe. A tubular tap 
body is located within the housing and has its axially spaced ends 
connected with axially spaced sections of milk pipe which extends within 
the vaccum pipe. A first port is arranged on the side wall of the tap body 
to allow communication with the milk pipe through the tap body, the first 
port facing the window opening. A tap frame is fixed to the housing over 
the window opening, and an air packing is mounted to the tap frame to form 
a second port which allows communication with the vacuum pipe through the 
interior of the housing. A gate is slidably mounted to the frame for 
simultaneously closing the first and second ports. 
The various features of novelty which characterize the invention are 
pointed out with particularly in the claims annexed to and forming a part 
of this disclosure. For a better understanding of the invention, its 
operating advantages and specific objects attained by its use, reference 
should be had to the accompanying drawings and descriptive matter in which 
there are illustrated and described preferred embodiments of the invention 
.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIGS. 1 to 3, a tap box unit includes a housing 10 and a pair 
of axially aligned connecting cylinders or tubes 11 extending from 
opposite ends and forming a part of the housing. A window 12 is also 
provided in an axially extending side wall of the housing, the window 
facing in a transverse direction relative to the axis of the tubes 11. 
Flanges 11a are formed at the ends of tubes 11, the flanges tapering 
outwardly to form openings of larger diameter than that of the tube 
bodies. 
A steel vacuum pipe 13 included a pair of axially aligned, spaced pipe 
sections is joined to the tubes 11 of the unit housing 10. A pair of metal 
sleeves 14 having flanged ends of identical cross section to the flanges 
11a are placed over the vacuum pipe sections, and the vacuum pipe sections 
are inserted into the tubes 11. Packings 15 are located about the sections 
between the tube flanges 11a and the flanges of sleeves 14, and notched 
bands 16 are tightened over confronting flanges (FIG. 2). Before inserting 
the vacuum pipe sections into the tubes 11 of the unit housing 10 and 
tightening the bands 16, the flanged sleeves 14, packings 15 and bands 16 
preferably should be inserted over the vacuum pipe sections. 
The V-notched bands 16 have a V-shaped cross section, and each of them 
includes a pair of semi-circular band members 16a, as shown in FIG. 5. 
Projections 16b extend radially outwardly at one end of each band member 
16a, and end clamps, 16c are formed at the other end of each band member 
16a. The V-notched bands 16 are assembled by selecting two band members 
16a, and a connecting plate 17 having a pair of holes 18 therein for 
engaging the projections 16b of the band members 16a. Screws 19 extend 
through the end clamps 16c of the band members thereby enabling the 
housing 10 to be fixedly joined with the vacuum pipe sections when the 
screws 19 are tightened. 
A milk pipe 20 extends within the vacuum pipe 13, the milk pipe being made 
of glass and including a pair of axially aligned spaced pipe sections. A 
rubber tubular milk tap body 21 has its axially spaced ends joined to the 
sections of the milk pipe by way of ring bands 22 at the joints. A port 23 
extends through the side wall of the tap body 21 intermediate the ends of 
the body for allowing a teat cup unit (not shown) to be connected with the 
tap body. As shown in FIG. 4, a tap adjusting metal plate 24 is located 
against the outside of the tap body 21 opposite the port 23. Milk tap body 
21 preferably is placed inside the tap housing 10 prior to connection of 
the vacuum pipe sections to the connecting tubes 11. Once placed inside 
the housing 10, the milk tap body 21 is joined to the milk pipe sections 
and fixed thereto by the ring bands 22. The port 23 in the milk tap body 
21 is positioned to face toward the window 12 of the housing 10, and an 
adjustment screw member 25 is screwed into the wall of the housing 10 
behind the tap body 21 to engage the adjusting plate 24 and securely fix 
the milk tap body 21 within the housing 10. 
A tap base or frame 26 is fixed over the window 12 of the tap housing 10 by 
screws 28, a packing seal 27 being provided between frame 26 and housing 
10. The milk tap body 21 is accurately positioned relative to the frame 
26. The tap frame 26 and the tap body 21 are securely fixed by the screw 
25 as it is screwed into the rear wall of the tap housing 10. 
An annular air packing 29 is mounted to the tap frame 26 so that the front 
of the packing 29 is in the same plane as the front of the port 23 in the 
milk tap body 21. Packing 29 forms, in combination with the frame 26, a 
second port which communicates with the interior of the housing 10. A 
sliding gate 30 is mounted to frame 26 for simultaneously closing the port 
of the air packing 29 and the port 23 of the tap body 21. It will be 
understood that port 23 of the tap body 21, and the port of the air 
packing 29 on the tap frame 26, communicate with the milk and vacuum pipes 
through the tap body 21 and the interior of the housing 10, respectively. 
An opening 31 is also provided in the sliding gate 30 for enabling the 
teat cup unit (not shown) to be connected with both ports. 
Since the teat cup unit is attached to the tap box unit only during a 
milking operation, a cover 33 is provided to protect the tap box unit from 
dust and the like. Cover 33 is sufficiently large to cover a substantial 
portion of the unit housing 10, and is mounted to the housing 10 for 
pivotal movement by means of a bearing plate 32 provided on the rear wall 
of the housing 10, and a pin 34. Cover 33 is pivoted upwardly during the 
milking operation, but at other times it is allowed to cover the housing 
10 as shown in FIGS. 3 and 4. When milking cows, cover 33 is pivoted 
upwardly and the teat cup unit is attached to the ports of the tap box 
unit. 
Although there are various types of cow sheds or milking barns, the most 
conventional have spaced partitions for housing one cow in each defined 
stall, and passages running in front of and behind the cows. In one type 
of barn, cow beds or pallets are provided on both sides of a passage. FIG. 
6 shows a type of cow barn where pallets 51 are provided on both sides of 
a center passage 50, although the drawing only shows one of the two rows 
of pallets 51. 
The pallet 51 is on a plane somewhat lower than that of the center passage 
50, and a feed box 53 is formed on the side closer to the center passage 
by means of a low wall 52, while on the opposite side of the feed box 53 
is provided a trough 54 for manure, as well as the side passage 55. A 
vacuum pipe with a milk pipe therein is preferably located close to the 
low wall 52 of the feed box 53. The diameters of the vacuum pipe 13 and 
the milk pipe 20 are preferably 64.5 mm and 50 mm, respectively, and the 
center of the vacuum pipe 13 is at a height of about 60 mm over the floor. 
At locations where the pipes cross the center passage 50 and the side 
passage 55, it is preferable to provide a groove deep enough to contain 
the pipes so that the passages remain at uniform levels. 
When milking cows with the arrangement of the present invention, cover 33 
is pivoted open, sliding gate 30 is pulled down to expose the air packing 
29 and the tap body port 23, and a pulsation tube of a teat cup (not 
shown) and associated milk tube are respectively connected to the port of 
the air packing 29 and the port 23. The pulsation tube connected with the 
air packing 29 communicates with the vacuum pipe 13 via the unit housing 
10, whereas the milk tube communicates with the milk pipe 20 by way of the 
tubular milk tap body 21. 
Inasmuch as the vacuum pipe 13 is connected to a vacuum generating device, 
and the milk pipe 20 to a milk processing plant, vacuum pressure and 
atmospheric pressure are alternatingly supplied to the teat cup unit by a 
pulsator attached to the teat cup unit, so that milk sucked through the 
teat cup unit when attached to the teats is sent to the milk processing 
plant through the milk pipe 20. The provision of a tap box unit and a dual 
pipe arrangement in accordance with the present invention facilitates 
locating the tap box unit at a position as close to the floor of a cow 
barn as possible, thereby eliminating differences of height between the 
teat cup unit and the tap box unit with its associated pipes. This 
arrangement avoids changes in vacuum applied to the cow's teats during a 
milking operation, and thereby prevents injury to the teats. 
While specific embodiments of the invention have been shown and described 
in detail to illustrate the application of the inventive principles, it 
will be understood that the invention may be embodied otherwise without 
departing from such principles.