US3430556A

US3430556A - Arrangement for a baling press

Info

Publication number: US3430556A
Application number: US599561A
Authority: US
Inventors: Gunnar Stoeng
Original assignee: Beloit Corp
Current assignee: Beloit Corp
Priority date: 1966-12-06
Filing date: 1966-12-06
Publication date: 1969-03-04
Anticipated expiration: 1986-03-04

Description

March 4, 1969 G. STGENG 3,430,556

ARRANGEMENT FOR A BALING PRESS Filed Dec. 6. 1966 Sheet of 2 I NVEN TOR.

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United States Patent Claims ABSTRACT OF THE DISCLOSURE A baling press incorporating a conveyor passing over a pressing table to deliver material to the pressing table to be pressed. The baling press includes a cylinder which is formed of pressure-tested and X-ray controlled cast steel and wherein the hydraulic cylinder includes a collar and a ring to align the extended portion of the hydraulic cylinder with that of the press table.

This is a continuation-in-part of application Ser. No. 569,135, filed Aug. 1, 1966, now Patent 3,376,809 issued Apr. 9, 1968.

This invention relates generally to a baling press and more particularly to a baling press arrangement for the baling of paper pulp. Specifically, the present invention is directed to an improved baling press construction which allows the baling press to be cycled many times per hour without effecting the structural integrity of the press, thereby increasing the average tonnage of baled pulp produced.

It is the usual practice in factories which produce paper pulp, such as cellulose, semichemical and mechanical wood pulp, to use baling presses in order to increase the density (specific weight) of the paper pulp bales, so as to make them more suitable for transport over long distances. In view of the increasing size of the production units in such factories, there has been a demand for large capacity baling presses. For example, baling presses having a capacity of 150 to 180 bales per hour are desired. A baling press which has a large bale-per-hour capacity naturally requires that each bale be formed in a minimum amount of time.

Modern baling presses, which have large bale-per-hour capacity, must work very quickly, with quick movements up and down of the main piston and the movable pressing board which is connected thereto. It is also important that the material being baled is transported into position under the movable pressing board and out from this position after the bale has been pressed quickly and efficiently. Therefore, it is evident that the time required to press each bale must be kept at a minimum. Furthermore, it is important that sufiicient pressing force is exerted on the bale during the short period of time allotted so that the material is adequately compressed. For example, a pressing force of 700 to 1000 tons is necessary. When a baling press is operated at high speed and at the high pressure necessary to achieve the desired bale-per-hour capacity, the hydraulic cylinder which urges the movable press table toward the bale is effected by the continuous reoccurrence of stresses and strains which act as low frequency high amplitude vibrations on the cylinder. Therefore, it is important to provide a baling press which has a main hydraulic cylinder which can withstand such vibrations.

It is known from practice how to arrange some form of transportation through the press, for example by steel band, balata belt, rubber band or by lamellas, and for the conveyer to have a driving pulley and a return pulley, and in such manner that the band is endless, so that there is no joint which can get under the bale when it is pressed 3,430,556 Patented Mar. 4, 1969 and make marks in it or tear up the wrapping sheet, or itself be damaged during the very high pressure to which it is subjected.

The bale or the stack is transferred to this conveyer from a feed-conveyer, for example in the form of a rolling table, and is carried in onto the pressing board directly underneath the pressing piston, after which the conveyer is stopped by means of an electric limit switch or in some other way, it being possible to provide the drive motor with a magnetic brake in order to insure instant stoppage of the conveyer. The pressing is effected preferably by the upper pressing board, which is coupled to the piston in a hydraulic cylinder, moving down and causing compression of the material. When it is accomplished and the movable pressing board has reached a certain distance upward, a suitable control switch may be actuated and the conveyer is started and carries the compressed bale out onto another conveyer for further transport, and at the same time carries a new bale in under the pressing piston.

As the conveyer band, which passes through the press itself, is situated between the bale and the lower pressing board, it is exposed to very high and frequent pressure stresses. These conditions cause a great amount of wear on the conveyer band. Thus, they must be capable of replacement after a relatively short operation time. As mentioned, the belt or band must be made endless, as joints are not permissible. Thus it has great significance to be able to exchange the belt or band easily and quickly and without the necessity for too much dismantling or the lifting of heavy parts.

The arrangement according to the invention aims at obtaining easy, convenient and rapid exchange of the conveyer band through the press, without having to dismantle or move heavy parts.

Therefore, one of the primary objects of the present invention is to provide a baling press with transport means which can quickly convey material into and out of the press during the baling operation.

Another object of the present invention is to provide a baling press with a conveyer belt for transporting material into and out of the press and which conveyer belt can be easily changed for maintenance.

Another object of the present invention is to provide a baling press which has an improved hydraulic cylinder construction so as to withstand high amplitude vibrations caused by the relatively high repetition rate of the press.

Briefly, the invention relates to a press of the abovementioned type, which has a lower pressing board which is supported along two opposite edges, rear edge and front edge, at a distance above the bottom frame of the press, and is provided wth a conveyer consisting of an endless band and two end rollers, over which the band is passed, namely a driving pulley on one side of the press and a return pulley on the other side which band is carried through the press over and under the pressing board respectively, and serves to carry material into the pressing position and after the material is pressed, it is carried out of the baling press.

One of the important features of the present invention is the design of a baling press which makes it possible to quickly and easily replace the conveyer band. This is accomplished by providing the front edge of the pressing board with a detachable distance-piece. When the conveyer band is being replaced, the lower pressing board is supported like a cantilever by a permanent supporting flange at the rear edge of the board. The press has a heavy duty bottom frame and base plate. A box shaped top frame is slidably mounted on standards and carries a traveling press table. The tie rods and nuts which are associated with the baling press are made to withstand dynamic stresses and strains and are dimensioned to withstand out-of-center loads which may occur during the pressing operation.

The main hydraulic cylinder is made of certified, pressure-tested and X-ray controlled cast steel. The cylinder is circular inside and outside along its entire axis, and has no ribs above the outer surface of the cylinder and no holes in the walls which might weaken the cylinder or act as points for stress concentration. Therefore ports are provided in a separate ring which is mounted at the end of the cylinder rather than boring such ports through the cylinder itself. This type of cylinder design is found advantageous to avoid local stress concentrations which would be particularly harmful to the cylinder due to the rapid cycling of the press.

Inlet of low pressure and high pressure oil to the main cylinder is arranged through a separate inlet piece mounted on the top of the cylinder. Also, a reservoir is carried on top of the cylinder to minimize feed lines between the cylinder and the hydraulic oil supply.

A pair of hydraulic cylinders are mounted on the top frame of the press to raise the movable press table upward at the end of the pressing operation. Also, a bumper is provided between the bottom surface of the main cylinder and the top surface of the movable press table to minimize ramming of the main cylinder by the press table.

Other objects and features will be more fully realized and understood from the following detailed description when taken in conjunction with the accompanying drawings in which like reference numerals throughout the various views of the drawings are intended to designate similar elements or components and wherein:

FIGURE 1 is a front elevation-a1 view of a baling press constructed in accordance with the principles of this invention;

FIGURE 2 is a side elevational view of the baling press of FIGURE 1; and

FIGURE 3 is an enlarged sectional view of the collar and ring shown in FIGURE 2.

Seen in FIGURES 1 and 2 is a baling press which is constructed in accordance with the principles of this invention, and is designated generally by reference numeral 10. A base 11 is mounted on a supporting floor 12. The floor 12 is provided with a recess 13 for receiving the lower portion 14 of the base 11.

A lower press table 16 is secured to the base 11 at its outer edges 16a and 16b. The edge 16a is provided with a permanent flange 17 and a plurality of gussets 18 to provide sufficient rigidity to support the table 16. It will be noted that the lower press table 16 forms a cantilever design when secured to the base 11 solely by the permanent flange 17.

The edge 16]) of the lower press table 16 is provided with a removable spacer 19 which is bolted in place by plurality of bolts 20 which extend through a portion of the lower press table, the spacer 19 and the base 11. The spacer 19 is provided with one or more hooks 21 to facilitate removal of the spacer.

By mounting the lower press table 16 onto the base 11 at the edges 16a and 16b, a space 22 is provided between the lower surface of the lower press table and the upper surface of the base 11. Therefore, the space 22 provides a passage for a conveyor belt 23 which has a portion positioned above the lower press table and a further portion positioned below the lower press table. The conveyor belt 23 is of the continuous type and is wrapped about a drive roll 24 and a tension roll 26. A support member 27 is positioned adjacent the drive roll 24 and carries a pair of

support rollers

29 and 30. Similarly, a support 28 is positioned adjacent the tension roll 26, and carries a pair of support rolls 31 and 32. As seen in FIGURE 1, the tension roll 26 has tensioning means 20a which urges the tension roll 26 toward and away from the drive roll 24. Therefore, the continuous conveyor belt 23 may be put into tension during operation, and may be released from tension to facilitate changing of the conveyor belt.

In operation, material to be baled is positioned over the lower press table 16 by the conveyor belt 23. The material, indicated by reference numeral 33, may be a preformed bale of relatively light density or may be formed by stacked sheets.

A plurality of

standards

36, 37, 38 and 39 are secured to the base 11 and extend upwardly to support a super structure 40. The superstructure 40 is a prefabricated welded assembly. A movable press table 41 is provided with a plurality of guide portions 42 which embrace the standards 36-39 so as to guide the press table 41 upward and downward in a fixed path.

Movement of the movable press table 41 is accomplishcd by the hydraulic actuator 43. The hydraulic actuator 43 includes a cylinder 44 and a piston 46 which, in turn, is secured to the movable table 41. The hydraulic actuator 43 is operated by hydraulic pumps not shown, from which hydraulic oil is supplied through a pair of pipes 48 and 49 and through an inlet piece 47 mounted on top of the cylinder 44. In addition, hydraulic oil is supplied from a reservoir 50 through a pre-fill valve mounted between the inlet piece and reservoir. The reservoir 50 with pre-fill valve serves the purpose of filling up the hydralic cylinder with oil during the first part of the downward stroke when oil under pressure is supplied to the two auxiliary cylinders 53 and 54, in order to achieve a quicker filling up of the main cylinder during this approach phase of the stroke.

As mentioned hereinabove, the superstructure 40 is of welded construction. However, the cylinder 44 of the hydraulic actuator 43 is constructed of certified, pressuretested, and X-ray controlled cast steel. Furthermore, the inside wall 44a and the outside 44b of the cylinder 44 are substantially concentric of one with the other along the entire axis of the cylinder. By providing a cylinder construction of this type, local stress concentrations are practically eliminated, thereby providing a hydraulic cylinder which is suitable for operation and to high repetition rates.

The cylinder 44 is provided with a flange 52 which extends radially outwardly from the outside wall 44b. The flange 52 is provided with a plurality of apertures for receiving a corresponding number of bolts 51 for securing the cylinder 44 to the superstructure 40.

To acquire the high repetition rate desired by the baling press of the present invention, the movable press table 44 must be raised from its pressing position after the material 33 has been sufficiently compressed. This is accomplished by providing a pair of hydraulic cylinders 53 and 54 which serve as lift actuators. That is, after the bale has been formed the movable press table 41 is raised to its initial position by the hydraulic cylinders 53 and 54. The hydraulic cylinders 53 and 54 are provided with a centering means so that when the movable press table 41 is raised to its initial condition, it will also be centered relative to the press axis. This is accomplished by providing an extended threaded portion 56 at the end of the hydraulic cylinder 53 which extends through an aperture 57 in the movable press table 41. A collar 58 is threadedly fastened to the extended portion 56 and is positioned above the surface of the press table 41. The collar 58 has an annular convex surface which engages a corresponding annular concave surface of a ring 59 as best seen in FIGURE 3. A retainer or nut 60 is provided to retain the extended portion 56 connected to the movable table 41. Therefore, lateral forces which are exerted on the movable press table may cause the movable press table to move laterally thereby displacing the ring 59 relative to the collar 58. However, the annular convex and concave surfaces of the collar and ring respectively will cause the movable press table 41 to shift back into its desired center position.

As mentioned here and above, an important feature of the hydraulic press of the present invention is that the hydraulic cylinder 44 is constructed of high quality cast steel. A seal ring 61 is secured to the lower end of the cylinder 44 and is provided with a pair of seal elements 62 and 63 which are in slidable contact with the piston 46. The seal elements 62 and 63 are provided to minimize hydraulic fluid leakage between the piston 46 and the inner wall 44a of the cylinder 44. Although sufficient precautions are taken to prevent hydraulic fluid leakage from existing between the inner wall 44a and the piston 46, it is reasonable to assume that normal wear of the seal elements 62 and 63 will eventually cause fluid leakage to exist. Therefore, an annular wall 66 is fastened to the movable press table 44 to form a trough 67 between the wall 66 and the outer peripheral surface of the piston 46. This trough will retain any hydraulic fluid which may leak from between the piston and the inner wall, thereby preventing such fluid from coming in contact with the material 33 which is being baled.

Therefore, the present invention has provided a baling press which is capable of baling a relatively large tonnage of material per hour due to the improved hydraulic cylinder design and due to the provision of suitable conveyor means for transporting the material into the press and after the material has been baled for transporting the material out of the press. It will be understood that suitable electric, hydraulic, or pneumatic control circuitry may be provided to start and stop the operation of the conveyor belt 33 in sequence with the movement of the movable press table 41.

It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.

I claim as my invention:

1. A baling press comprising:

a base;

a lower press table mounted at opposite edges on said base to provide a space between the top surface of said base and the bottom surface of said lower press table;

a continuous conveyor belt movably mounted on the baling press having a portion thereof passing over said lower press table and a further portion thereof passing within said space under said lower press table;

piston means supported by said base over said lower press table for pressing material which is conveyed by said conveyor belt and positioned between said lower press table and said piston means;

means provided along one of said opposite edges of said lower press table for disconnecting the edge from said base to allow said conveyor belt to be removed from about said lower press table, wherein said piston means includes a cylinder;

a plurality of standards mounted on said base outwardly of said lower press table for supporting said cylinder;

a ram slidably mounted within said cylinder;

a movable press table mounted on said ram;

lifting means mounted at the upper end of said standards and connected to said movable press table to raise said movable press table at the end of a pressing operation, and

wherein said cylinder is formed of pressure-tested and X-ray controlled cast steel, and wherein the inner and outer surfaces of said cylinder are concentric circles extending along the entire axis thereof.

2. A baling press comprising:

a base;

a ram slidably mounted within said cylinder;

a movable press table mounted on said ram;

wherein said lifting means includes at least one hydraulic cylinder having a threaded extended portion extending through an aperture in said movable press table;

a collar threaded on said extended portion, said collar having an annular convex surface adjacent one surface of said movable press table;

a ring having a corresponding concave surface for engagement with said convex surface, said ring being positioned between said collar and said one surface and in substantial alignment with the aperture in said movable press table;

and a retainer threaded on said extended portion and positioned opposite said one surface;

whereby, said collar and said ring serve to align said extended portion with the aperture in said movable press table.

3. The baling press of claim 2 further including a bumper secured to said cylinder and positioned to be engageable with said movable press table when said movable press table is raised by said hydraulic cylinder.

4. A baling press comprising:

a base;

a ram slidably mounted within said cylinder;

a movable press table mounted on said ram;

a bumper secured to said cylinder and positioned to be engageable with said movable press table when said movable press table is raised by said lifting means.

5. A baling press comprising:

a base;

a lower press table mounted at opposite edges on said base to provide a space between the top surface ot said base and the bottom surface of said lower press table;

a ram slidably mounted within said cylinder;

a movable press table mounted on said ram;

an annular wall portion secured to said movable press table and positioned about said ram to form a trough between said ram and said annular portion for retaining hydraulic fluid which escapes from said cylinder.

References Cited UNITED STATES PATENTS 1,949,917 3/1934 Muench 100-2l8 XR 2,084,980 6/ 1937 Sweeney. 2,159,779 5/ 1939 Cavin 100-222 BILLY J. WILHITE, Primary Examiner.

US. Cl. X.R.