US2991971A - Telescopic compensating unit - Google Patents

Description

y 1961 0. HOFFLIN 2,991,971

TELESCOPIC COMPE"\L'SAT1NG UNIT Filed Feb. 11, 1958 INVENTOR. OTTO HOFF L! N 'S A TTORNEYS "this cylinder through a passage Patented July 11, 1961 tic This invention relates to compensating units for receiving a continuous flow of viscous material and delivering the collected material intermittently and, more particularly, to a new and improved compensating unit arranged to eliminate loss of the viscous material.

In apparatus for handling viscous material under pressure, compensating devices for coupling continuous and intermittent flow stages are well known. Many of these devices such as the device described in the United States patent to Wilson et al. No. 2,474,136, for example, include an accumulating cylinder supplying material from a continuously operating production stage to an intermittent packaging stage and a piston movable within the cylinder under controlled pressure. Viscous material from the continuous stage is customarily received through an aperture in the piston and distributed thereby in a uniform manner at the end of the cylinder opposite the intermittent stage, a telescopic connection being provided in the supply line to accommodate the movement of the piston. Inasmuch as the viscous material flows through the apparatus under pressure, some'of the material being processed inevitably leaks out between the sliding members of the telescopic connection in the supply line, resulting in substantial contamination or loss of the material.

Accordingly, it is an object of the invention to provide new and improved apparatus for handling viscous material arranged to prevent loss of material by leakage from the supply line.

Another object of the invention is to provide apparatus of the above character wherein any material leaking through the telescopic connection is not wasted.

These and other objects of the invention are attained by supplying the viscous material through a fixed tube to a telescopic connection within the accumulating cylinder. From the movable part of the telescopic connection the viscous material is delivered to the operating surface of the piston for distribution across the end of the cylinder opposite the intermittent stage in the usual manner.

Further objects and advantages of the invention will be apparent from a reading of the following description with reference to the accompanying drawing in which:

FIG. 1 is a longitudinal section through a typical compensating unit arranged in accordance with the invention; and

FIG. 2 is a cross sectional view taken on the line 2-2 of FIG. 1 looking in the direction of the arrows.

As illustrated in FIG. 1, a representative embodiment of the invention comprises an accumulating cylinder 1, open at both ends and having at one end a flanged orifice 2 which may be connected to apparatus, such as a packaging device (not shown), intermittently accepting viscous material from the cylinder. At its other end the accumulating cylinder, which terminates in a flange 3, is connected by distance-bolts 4 to a pressure cylinder 5 in coaxial alignment, pneumatic pressure being supplied to 6 in a cover 7 closing the end of the cylinder away from the accumulating cylinder.

In order to transmit the pneumatic pressure to the viscous material within the accumulating cylinder 1, a freely movable piston 8 is positioned within the accumulating cylinder and connected by longitudinal shafts 9 to a piston 10 movable within the pressure cylinder 5, each piston being provided with suitable packing to form a fluid-tight seal with the corresponding cylinder. Viscous material is continuously supplied to the compensating unit under pressure through a tube 11 which passes through an opening in the side of the accumulating cylinder 1 and is sealed therein by a weld 12, the inner end 13 of the tube 11 being positioned coaxially with the cylinder and directed toward the piston 8. Telescopically engaging the end 13, a hollow tube 14 leads through a socket 15, by which it is aflixed to the piston 8, to aseries of radial channels 16 which distribute the viscous material across the working face of the piston, thus assuring uniform spreading of the material over the cross section of the piston 8. In order to accommodate the full stroke of the piston 8, the tube 14 and the coaxial end of the tube 11 are made at least as long as the distance-bolts 4, which determine the maximum stroke.

Leakage of the viscous material between the sliding surfaces of the tubes 13 and 14 is substantially eliminated by a gasket 17, but it will be noted that inasmuch as the accumulating cylinder 1 is filled with the same material during operation, any substance which does leak out is not lost but mingles with the material flowing toward the orifice 2. Further, it will be observed that the tendency for material to leak through the telescopic connection is, in this case, greatly reduced as compared with compensating units wherein the telescopic connection is outside the accumulating cylinder, since the pressure of the material surrounding the connection is substantially the same as that within the sliding tubes.

As best seen in FIG. 2, a block 18, clamped to two of the rods 9, supports a longitudinal shaft 19 which passes along the outside of the accumulating cylinder and has two spaced rollers 20 and 23 affixed at the opposite end. Positioned between the rollers an arm 21 is arranged to operate a valve 22 controlling the supply of the material to the tube 11. When the block 18 is against the flange 3 the arm 21 is moved by the roller 23 so that the valve 22 is fully opened. As the block 18 travels away from the accumulating cylinder the shaft 19 first brings the roller 20 into contact with the arm 21 which then gradually closes the valve until it is completely shut when the block 18 meets an abutment plate 24 adjacent the pressure cylinder 5, thus preventing overloading of the accumulating cylinder.

In operation, viscous material is continuously supplied to the tube 11 and pneumatic pressure is applied to the piston 10. This pressure is transmitted through the shafts 9 and the piston 8 to the material within the accumulating cylinder 1, forcing it out through the orifice 2 whenever the intermittent stage is in condition to receive it. If the quantity of material supplied to the tube 11 over an interval of time is greater than the quantity discharged in this manner, the piston 8 progresses toward the cylinder 5, moving the arm 21 by means of the shaft 19 to reduce the supply of material. On the other hand, the shaft 19 moves the arm 21 to increase the flow when the amount forced through the orifice 2 is greater than the supply. Under the usual operating conditions, however, when the flow has been automatically adjusted in this manner, the piston 8 moves back and forth within a limited range during each delivery cycle so that neither of the spaced rollers 20 and 23 actuates the control arm 21.

It will be understood that the embodiment described herein is illustrative rather than restrictive of the invention. Accordingly, various modifications and changes therein will occur to those skilled in the art which do not exceed the intended scope of the invention as defined by the following claims.

I claim:

1. Apparatus for coupling in a flow system, said apparatus comprising means forming a chamber having an inlet means and an outlet means, a piston movable within the chamber to vary the capacity thereof, said piston having a working face, means for applying a force to urge the piston in a direction to decrease the capacity of the chamber, said inlet means including a first fixed tube leading into the chamber and including a portion parallel to the direction of motion of the piston, and a second tube fixed to the working face of the piston and slidably engaging said portion of the first fixed tube, said second tube having port means opening from the interior thereof to said chamber closely adjacent to the working face of the piston.

2. Apparatus according to claim 1 wherein the second tube is aflixed centrally to the Working face of the piston and the port means comprises a plurality of radial channels angularly disposed about the end of the second tube.

3. Apparatus for coupling in a flow system, said apparatus comprising means forming a chamber having an inlet means and an outlet means, a piston movable Within the chamber to vary the capacity thereof, said piston having a working face, pressure means for urging the piston in a direction to decrease the capacity of the chamber, said inlet means including a first fixed tube leading into the chamber and including a portion parallel to the direction of motion of the piston, and a second tube fixed to the Working face of the piston and slidably engaging said portion of the first fixed tube, said second tube having port means opening from the interior thereof to said chamber closely adjacent to the working face of the piston.

4. Apparatus for coupling in a flow system, said apparatus comprising means forming a chamber having an inlet means and an outlet means, a piston movable Within the chamber to vary the capacity thereof, said piston having a working face, pressure mean normally urging the piston in a direction to decrease the capacity of the chamber, said inlet means including a first fixed tube leading into the chamber and including a portion parallel to the direction of motion of the piston, and a second tube fixed to the working face of the piston and slidably engaging said portion of the first fixed tube, said second tube having port means opening from the interior thereof to said chamber closely adjacent the Working face of the piston, and control means in said inlet means, said control means operatively associated with the piston so as to be responsive to the position thereof to regulate flow through the inlet means.

References Cited in the file of this patent UNITED STATES PATENTS 295,532 Francis Mar. 25, 1884 540,003 Reed May 28, 1895 726,155 Fulton Apr. 21, 1903 1,010,834 Westburg Dec. 5, 1911 1,885,000 Muller Oct. 25, 1932 2,474,136 Wilson Jan. 2l, 1949

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