US2985388A - Automatic safety release for adjusting means for pulp refiners and the like - Google Patents

Description

y 2 1961 R. B. HONEYMAN 2,985,388

AUTOMATIC SAFETY RELEASE FOR ADJUSTING MEANS FOR PULP REFINERS AND THE LIKE Filed June 29, 1959 2 Sheets-Sheet l INVENTOR.

F[g J ROBERT B. HONEYMAN ATTORNEY y 61 R. B. HONEYMAN 2,985,388

AUTOMATIC SAFETY RELEASE FOR ADJUSTING MEANS FOR PULP REFINERS AND THE LIKE Filed June 29, 1959 2 Sheets-Sheet 2 Fig: ,3-

INVENTOR. ROBERT B. HONEYMAN Fig 5 ATTORNEY AUTOMATIC SAFETY RELEASE FOR ADJUSTING NEANS FOR PULP REFINERS AND THE LIKE Robert Blakeley Honeyman, Portland, Oreg., assignor to Morden Machines Company, Portland, reg., a corporation of Oregon Filed June 29, 1959, Ser. No. 823,672

2 Claims. (Cl. 241-32) This invention relates in general to various types of machines for the treating and refining of pulp material, and, more specifically, to machines in which the material receives its treatment by being required to pass between op.- posed attritioning surfaces of a rotating element and an opposing non-rotating element, often referred to as a shell or stator.

As is well-known, adjustment of the spacing between the opposed attritioning surfaces or working faces of the rotating and non-rotating elements is essential from time to time, not only to compensate for wear on the working faces of the elements, but also to regulate and control the treatment given to a particularmaterial. Consequently such machines are provided with means for adjusting the rotating element in an axial direction with respect to the non-rotating element, as for example adjusting the frustoconical rotating plug in an axial direction in a Jordan machine or the plates in a disc refining machine, or for adjusting the non-rotating shell or plate in an axial. direction with respect to the rotating member.

However, it may happen than an operator, when making the adjustment of the position of one element axially with respect to the other, will cause the opposed working faces .to be brought too close together for the desired or most efficient treatment of the particular material passing through the machine, or else it may happen that material of heavier quality and consistency will beintroduced into the machine without proper adjustment being made in the spacing between the working faces of the two elements. In either case the material does not receive the most satisfactory treatment desired while, at the same time, a greater load is imposed on the motor or driving means for the rotating element. -Also, when this occurs, the

'axial thrust on the axially adjustable element is increased as a result of the increased pressure of the material as it passes between the opposed working faces. Occasionally it may happen that foreign objects, such as .tramp metal, may be included in the material being passed through the treating machine. Such foreign objects, in attempting to force their way between the working faces, will damage the machine extensively unless the spacing between the working faces is instantly increased under the increased axial thrust. In the present invention such increased axial thrust, due to any of these causes, upon reaching a predetermined limited amount, is utilized to produce an automatic partial release for the position adjusting means.

The object of the invention accordingly is to provide automatically operating release means in conjunction with the positioning means for the adjustable element in the pulp treating machine, which will enable the adjustable element automatically and instantly to be moved slightly away from the companion element, thus increasing the spacing between the opposed working faces of the elements, whenever the axial thrust on the adjustable element exceeds a desired predetermined amount.

A related object of the invention is to provide such an automatic release which can quickly and easily be ad- Patented May 23, 1961 justed so as to be pre-set for any desired maximum limit of axial thrust on the adjustable element.

Another object of the invention is to provide an automatic release to be used in conjunction with mechanical adjusting means, which will not at any time interfere with, or render inoperative, such mechanical adjusting means.

A still further object is to provide an automatic, pressure-operated, safety release for the adjusting means on pulp refiners and the like which will be simple and practical in construction and which will not present any particular maintenance problem.

The manner in which these objects and incidental advantages are achieved with the present invention will be readily understood from the following brief description and explanation with reference to the accompanying draw ings. I

In the drawings:

Fig. 1 is a fragmentary plan view of a pulp refining machine with part of the automatic safety release mounted thereon, with portions of the machine and safety release shown in section for clarity, and with the connected automatically-actuated safety release control shown diagramatically in elevation and partly in section;

Fig. 2 is a fragmentary sectional elevation on line 2-2 of Fig. 1A drawn to a larger scale; and

Fig. 3 is an end elevation, partly in section, of the pulp refining machine of Fig. 1 taken on line 3-3 of Fig. 1.

The pulp refining machine shown in part by way of illustration in Fig. l is a machine of atype described in US. Patent No. 2,547,830, issued under date of April 3, 1951, to C. W. Morden and entitled Treating and Refining Mac hine for Pulp Materials; and this machine includes a housing 10, a non-rotating frusto-conical shell -11 mounted in the housing, and a frusto-conical roto'r (not shown) co-axial With the shell and rotating Within. the shell, the pulp being caused to pass between the opposed attritioning surfaces of the shell and rotor. In order to provide for adjustment of the spacing between the two attritioning elements the shell is adjustable in an axial direction. In this particular device the shell has a pair of diagonally opposite integral side arms 12 which carry a pair of guides 13 respectively, which guides are slidable in semi-cylindrical guideways 14 provided in the interior wall of the housing 10. A pair of positioning shafts 15, which are parallel to the axis of the shell and rotor, have their reduced inner ends rigidly secured to the arms 12 and guides 13 by clamping nuts 15. The outer ends of these shafts are threaded and carry identical adjusting nuts 16 (see also Fig. 2). The outer peripheries of these adjusting nuts 16 are provided with gear teeth adapted for meshing with a pair of identical worms 17 secured on an adjusting shaft 18. A hand wheel 19, secured on the shaft 18, enables the axial position of the shell to be manually adjusted. This means for adjusting the position of the shell in an axial direction with respect to the rotor, as thus far described, is similar to that provided in the machine in the above mentioned patent. Obviously power driven means could be used in place of the manual means for rotating the shaft 18 and thus for operating the shell adjusting mechanism.

In the carrying out of the present invention a pair of specially shaped identical housings 20 are provided for the outer end portions of the two positioning shafts 15 respectively. The end of each housing 20 is formed into a hydraulic cylinder 21 and is provided with a hollow hydraulic piston 22. One side of the adjusting nut 16 bears againstthe adjacent end of the associated piston 22 through the intermediary of suitable ball-bearings and race 23. The other side of the adjusting nut 16 is engaged by a Washer 24' against which a spring 24 bears, which spring is held under compression between the adjusting nut 16 assasss and washer and the other end of the housing 20. Thus the springs 24 keep the adjusting nuts 16 in engagement with the respective pistons 22 at all times. The adjusting nuts and their pistons are allowed a slight movement axially within their housings. A suitable key and keyway 25 hold each hydraulic piston 22 against rotation while permitting sliding movement of the piston in an axial direction.

The two hydraulic cylinders 21 are connected through a common pipe line 26 with one side of a pressure cylinder 27 and thus with the chamber 29 of the pressure cylinder 27 as shownin Fig. 1. A diaphragm 28 separates the cylinder 27 into the two chambers 29 and 3t) and seals the two chambers from each other while allowing opposite volumetric fluctuation in the two chambers. A branch pipe 26' connects the pipe 26 to an electric pressure switch 31 of well-known type. The chamber 29, the pipes 26 and26' and the ends of the two hydraulic cylinders 21 are filled with a suitable hydraulic liquid, such as oil, through an oil fill 32 having a shut-off valve.

The other chamber 3d of the cylinder 27 is connected to a pipe 34 which in turn is connected to a suitable source (not shown) of other fluid (such as water or compressed air), through the intermediary of the control valve 35. A relief valve 36, operated by a solenoid 37, and a pressure gauge 38 are also connected with the pipe 34. The solenoid 37 is connected to a source of electric energy by means of electric pressure switch 31.

The chamber 30 and pipe 34 are filled with fluid until a predetermined pressure is indicated on the gauge 38. Then the valve 35 is shut off to seal the fluid in the chamber 30 and pipe 34. The device is now ready for operation as follows (referring to Fig. l):

The adjustment of the spacing between the opposed attritioning surfaces of rotor and shell is first accomplished as usual by manual rotation of the hand wheel 19 (or other means may be used for rotating the shaft 18 and thus adjusting the positioning shafts 15 and therewith adjusting the shell 11). Then the electric pressure switch 31 is set so as to operate the solenoid 37 for the relief valve 36 whenever the pressure in the pipe line 26, and thus in the hydraulic cylinders 21 exceeds a desired predetermined amount, and thus whenever the pressure of thepulp between the attritioning surfaces of the rotor and shell becomes such that the axial thrust on the adjustable element or shell is greater than desired under the particular conditions of operation. Should the shell position inadvertently be adjusted so that the opposed attritioning surfaces are-brought too close together, then, when the machine is operated, resulting excessive pressure of the material passing between the opposed attritioning surfaces will increase the thrust of the shafts 15 against their pistons 22 and increase the pressure in the hydraulic cylinders 21,

and thus allow the positioning shafts l and therewith the shell 11, to be moved slightly (to the leftas viewed in Fig. 1), under the force of the excessive axial thrust, so as to increase slightly the spacing between the shell and rotor. When this occurs the reduced pressure in chamber 30will be apparent from the lowered position of the indicator of gauge 38. a 7

To re-set the safety release the operator opensthe valve 35 temporarily to enable additional fluid to be delivered into the pipe 34 and chamber 30 so as to bring the pressure indicated by the gauge 33 again up to the desired level. When subsequent manual adjusting of the position of the shell lowers the reading of pressure. gauge 38 the 42 valve 35 is again opened and the pressure restored to the desired level for the system.

In the example illustratedthe adjusting means and the safety release for the same have been shown as being employed with an axially adjustable shell or non-rotating element which is adjustedaxially by the pair of positioning shafts 15 attached to the shell 11 at diametrically ,opposite points. The two springs 24, hearing against the respective nuts 16, cause uniform movement of the shafts (to the left asviewed in Fig. 1) even though the increased axial thrust on the shellis transmitted mainly to one of the shafts. It is to be understood that the invention also operates in exactly the same manner when the rotating element, instead of the non-rotating element, is made axially adjustableand thus when thenon-rotating element remains fixed. With some pulp treating and refining machines it has become common practice for the rotor shaft to be mounted in a bearing housing, which bearing housing in turn isadjustable along the common axis of the .two elements, thus'enabling the position of the rotor element to be adjusted axially with respect to the non-rotating and non-adjustable element. In suchtcaser the present invention is employed in the same manner as previously described for providing the same automatic safetyrelease for the similar mechanical means used for adjusting the axial position of suchbearing housing for the rotor shaft.

IWhei'e the bearing housing for the rotor shaft is adjustable axially only one positioning shaft may be required for positioning the bearing housing. Again in other machines more than two positioning shafts may be used, especially when a shell of considerable sizeis the adjustable element, thepositioning shafts of course always being adjusted in unison.' Thus the invention may be employed in the same manner where there is only a single positioning shaft or where a plurality of positioning shafts areemployed.

I claim: 1., In a material treating machine of the character described having ,a pair of axially aligned elements with .opposedworking faces and one of said elements being axially adjustable with respect to the other, an adjusting shaft connected tosaid adjustable element, a threaded porsettable pressure-operated switch in said closed hydraulic circuit, a chamber connected to said closed hydraulic circuit,,a diaphragm forming one wall of said chamber, a second chamber on the other side of said diaphragm, a

closed fluid pressure circuit connected to said second chamber, a relief valve in said second mentioned circuit, electrical. means for operating said relief valve, said electricalmeans actuated by said pressure-operated switch,

whereby when the passage of material between said elements causes a thrust onsaid axially adjustable element and therewith on said nut and said piston in excess of that for which said switch is set, the operation of said relief valve and the resulting extension of said diaphragm will enableslight axial movement of said piston, nut and adjustable element to take place in response to and relief of the excessive pressure.

2. -A'material treating machine including a rotating element, a coaxial non-rotating element, said, elements having opposed working faces for treating the material passing therebetween, means for adjusting said non-rotating elementraxiallywith respect to said rotating element, said means comprising apluralityof positioning shafts connected with said non-rotating elementand extending parallel to the axis ,of saidnQH-lotating element, each of said shafts having an identically threaded portion, identical adjusting nuts on said threaded portions, worm gear means for rotating said nuts in unison, a hydraulic cylinder in axial alignment with each shaft, a piston in each cylinder, said pistons bearing against said nuts respectively on the sides of said nuts remote from said non-rotating element, spring means bearing against the opposite side of each nut and holding the nut against its piston, a closed hydraulic circuit connected to said cylinders normally maintaining said pistons and therewith said nuts against axial movement, a pre-settable pressure-operated switch in said closed hydraulic circuit, a chamber connected to said circuit, a diaphragm forming one wall of said cham her, a second chamber on the other side of said diaphragm, a closed fluid pressure circuit connected to said second chamber, a relief valve in said second mentioned circuit, electrical means for operating said relief valve,

6 said electrical means actuated by said pressure-operated switch, whereby when the passage of material between said elements causes a thrust on said non-rotating element and therewith on said nuts and pistons in excess of that for which said switch is set, the operation of said relief valve and the resulting extension of said diaphragm will enable slight axial movement of said pistons, nuts and non-rotating element to take place in respo'nse to and relief of the excessive pressure.

References Cited in the file of this patent UNITED STATES PATENTS 2,547,830 Morden Apr. 3, 1951 2,674,163 Prevost Apr. 6, 1954 2,743,874 Asplund May 1, 1956 2,876,958 Edwards et al Mar. 10, 1959

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