US2876443A - Adjustment position indicator for longitudinally adjustable element - Google Patents

Description

March 1959 R B. HONEYMAN 2,876,443

ADJUSTMENT POSITiON INDICATOR FOR LONGITUDINALLY ADJUSTABLE ELEMENT Filed April '11, 1957 2 Sheets-Sheet 1 I l 9 I3 5 .3

12 v INVENTOR. H ROBERT BLAKELEY HONEYMAN ATTORNEY ADJUSTMENT POSITION INDICATOR FOR LONGI- TUDINALLY ADJUSTABLE ELEMENT Robert BlakeleyHoneyman, Portland, Oreg., assignor to Morden Machines Company, Portland, Greg, a corporation of Oregon Application April 11, 1957, Serial No. 652,185

2 Claims. (Cl. 340-282) This invention relates in general to machine operating assemblies in which some portion or element, for example, a shaft, or the support or hearing mounting therefor, is so arranged as to enable a desired, slight, controllable adjustment of the element to be made in an axial or longitudinal direction.

In particular the present invention relates to such machines as pulp-treating machines in which careful adjustment of the spacing between the opposed working faces of the rotating and stationary elements is essential to securing desired efiicient results, and such adjustment is obtained through means by which one of the elements, for example, the driven shaft of the rotor, can be adjusted longitudinally according to requirements. An example of a pulp treatingmachine in which careful adjustment of a rotor shaft, with respect to a. cooperating stationary element must be made from time to time in the treatment of the fibrous or pulp material, is described in U. S. Patent No. 2,654,294 issued under date of October 6, 1953, to C. W. Morden and entitled Pulp Shredding and Treating Machine, and, while the illustrations in that patent show a manually operated worm gear for adjusting the rotor shaft position, motor operated means can also be employed for making such rotor shaft adjustment. It will be readily understood that such adjustment is required not only as the particle size and consistency are modified but also, from time to time, to compensate for wear of the opposed working surfaces of the elements. Also, in batch operations, it is necessary to re-set the relative position of the opposed working surfaces after the conclusion of one batch and the cleaning of the surfaces before the starting of another batch. It will also be appreciated that in such types of machines, these adjustments in any case are very slight, not exceeding a fraction of an inch, and that they must be. carefully controlled inasmuch as carelessness in making such adjustments can be detrimental. Thus there will be excessive friction between the working surfaces if the clearance is too close, and there should be increased clearance at the start of operations, partly to avoid overload when starting the motor.

An object of the present invention is to provide an improved indicator by which the operator can tell at a glance the relative position of the particular member which is in the process of being adjusted.

Another object of the invention is to provide an improved indicator which can readily be reset for any desired predetermined adjustment to be made in the position of the adjustable element, and thus an indicator which will in itself be easily adjustable and resettable.

In a pulp-treating machine wear gradually takes place in the working surfaces of the rotating and stationary elements, and in maintaining the desired relative position of the two elements with respect to each other, such wear of the working or attritioning surfaces of the two elements must be compensated for. A further and important object of the invention accordingly is to provide a position indicator of the type mentioned which will be capable of ited States Patent ice 2 self-adjustment in order to accommodate such wearing of the elements and becapable of indicating correctly the relative positions of the two surfaces regardless of wear.

An additional object of the invention is to provide a position indicator for an adjustable element which will be simple and practical in construction and which will require only a minimum amount of care in its operation and maintenance. I p

The manner in which these objects and other incidental advantages are attained with the indicator of the present invention will be readily understood from the following brief description with reference to the accompanying drawings.

In the drawings:

Figure l is a side elevation showing the device secured in stationary position adjacent the adjustable bearing housing in which a rotor shaft, the position of whichis required to be adjusted, is mounted; the signal lights operated by the device, which may be located at any convenient point, being, omitted from the figure;v

Figure 2 is an elevation of the device by itself, drawn to a larger scale, with the front cover plate removed and with a portion of the device broken away and part shown in section for the sake of clarity;

Figure 3 is an end elevation of the device taken on the line indicated at 3-3 in Figure 1;

Figure 4 isa cross section on line 44 of Figure 2, but drawn to a slightly larger scale;

Figure 5 is a cross section on line 55 of Figure 2, drawn to the same scale as Figure 4;

Figure 6' is a top plan section corresponding to line 6-6 of Figure 2; and

Figure 7 is a wiring diagram.

For the purpose of this description it is assumed that the longitudinally adjustable element is a shaft which carries the rotor element in a pulp treating machine, such as that described in U. S. Patent No. 2,654,294, previously mentioned, wherein the rotor has a Working or attritioning surface cooperating with the companion working or attritioning surface on a stationary annular or ring member and wherein the proper adjustment of the slight spacing between the two working surfaces is essential. However, the invention is not to be understood as limited to employment with any particular adjustable element or shaft or in any particular type of machine, but is capable of use with any element which is longitudinally or axially adjustable and the careful relative positioning or adjustment of which is highly important.

Referring first to Figure 1 of the attached drawings, the adjustment position indicator designated in general by the reference character It) is shown secured in place on a stationary mounting support 11 for a housing 12 containing bearings for the horizontal rotor shaft (not shown), the housing, and therewith the rotor shaft, being adjustable to a limited extent in either direction axially with respect to the stationary mounting support 11. In a machine of this type such adjustment of the housing 12 and.

of the rotor shaft would be accomplished through the medium of a manually operated hand wheel, a reversible electric, air or hydraulic motor, or other means (no such means being shown), connected with the housing 12 through suitable reduction or worm gear assembly. An arm 13, secured to the adjustable housing 12, engages a spring-controlled push rod 14 of the indicator.

The indicator 10 is located in a special housing 15 (Figures 2, 4, 5 and 6) having a removable front plate 16, this plate being shown removed in Figure 2. The push rod 14 is slidable in a bearing 17 located in one end of the indicator housing 15, this bearing also preferably including a suitable dust seal (not shown) to prevent the entrance of any dust into the interior of the indicator housing 15.

' A housing member 18, the shape of which is shown best in Figures 2 and 6, extends through and is secured on the opposite end of the indicator housing 15. This member 18 has a cylindrical channel orrecess 19 of the proper size to accommodate the inner end of the push rod 14 and this channel is in axial alignment with the bearing 17. The outer end of the member 18 is closed and a coil spring I 20, contained in the recess 19, engages the end of the push rod 14 exerting a force to move the push rod to the left (as viewed in Figure 2) but permitting movement of the push rod to the right against the force of spring 20 to an extent equal at least to the maximum amount of adjustment which may be required in the machine. A 'collar 21, secured on the push rod 14 by a set screw 22, limits the possible travel of the push rod to the left under the force of the spring 20 in order to prevent the inner end of the push rod from inadvertently being allowed to move out from the channel 19 of the stationary member 18.

A plate 23 (Figures 2, 4 and 6) is firmly secured within the indicator housing 15, being attached by screws to a pair of brackets 24, 24 (Figure 4)' which are integral with the opposite housing walls respectively. A pair of microswitch assemblies 25 and 26 are mounted on the plate 23 in the respective positions shown in Figures 2 and 4.

These micro switches are provided with spring-controlled actuating 'plungers 25' and 26'v respectively which are sensitive to the slightest thrust inwardly. The purpose of these micro-switches is to produce the operation of signal lights indicated in Figure 7 and referred to later, thesignal lights preferably being different in color so as to be more easily distinguished by the operator from a distance.

A sleeve 27 is carried on the push rod 14 and is normally held in a set position on the push rod by means of a clamping shoe 28 (Figure which bears against the push rod 14 and which is carried in a cavity provided in the sleeve 27. A spring 29 bears against a washer 30 in contact with the shoe 28 and the outer end of the spring 29 is engaged by the screw cap 31. Thus the spring pressure on the clamping shoe 28, under normal conditions, holds the sleeve 27 in set position on the push rod 14 and causes it to move with the push rod.

The sleeve 27 is provided with a pair of identical arms 32 and 33 extending in opposite oblique directions. The arms 32 and 33 carry adjustable cap screws 32' and 33' respectively, which are so positioned as to be in alignment with the actuating plungers 25' and 26' respectively of a pair of double- acting limit switches 25 and 26. Preferably these cap screws are provided with jam nuts 34 in order to prevent any possible inadvertent turning of these screws. As apparent from Figure 2, the cap screws 32 and 33' are intended to operate the switches 25 and 26 respectively in one direction whenever the push rod 14 and the sleeve 27 are moved sufiiciently to the right against the force of spring to cause them to contact the plungers of the switches, and to permit the switches to return to normal position by moving in the opposite direction whenever the rod 14 and sleeve assembly are moved far enough to the left.

Referring now to the diagram in Figure 7, the switch normally is in engagement with the contact 39, but, when moved by the plunger 25' engages the contact 38. Similarly, the switch 26 engages the contact 40 except when moved by the plunger 26' in which case it engages the contact 41.

When both switches are in their normal positions indicated in the diagram, the circuit is closed through the conductor 46, contact 39, conductor 42, through a signal light 35 (preferably green in color), and the conductor 47. In other words, when neither switch is moved by its plunger, the circuit through signal light 35 will be closed. When switch 25 is moved to engage-contact 38,

" signal light 35 ceases to be actuated and the circuit will be closed through conductor 46, contact 38, conductor 43, contact 40, conductor 44, signal light 36 (preferably of another color, for example amber) and conductor 47. When switch 26 now is moved to engage contact 41 signal light 36 in turn ceases to be actuated and the circuit will be closed through conductor 46, contact 38, conductor 43, contact 41, conductor 45, signal light 37 (preferably red in color) and conductor 47 Assuming, for example, that the device is to be used for indicating the position of an axially adjustable shaft (or, more specifically, for the axially adjustable bearing housing'for the shaft) for the rotor in a pulp-treating machine of the type mentioned at the beginning of this specification, and assuming that it is desired to have the green signal light show when the spacing between the stationary attritioning element and the cooperating attritioning surface of the rotor is greater than /a of an inch, to have the amber light show in place of the green light when such spacing is reduced to 3 8 of an inch, and finally to have the red light show, in place of the amber light, when the spacing has been reduced to ,4, of an inch, the device will be initially set up as follows:

With the pulp-treating machine not in operation, the rotor shaft and its bearing housing 12 are moved (to the right with reference to Figure 1) until the attritioning faces of the rotor and the cooperating stationary ring (not shown) have been brought into actual contact. The sleeve 27 is slid (to the right) until it contacts the inner end 18 of the member 18. While the sleeve 27 is being held in this position the push rod 14 is moved (to the left) until it bears against the arm 13 on the bearing housing 12. Then the cap screw 32 is screwed in A; of an inch beyond the point at which the amber light is turned on against the spring pressure of the plunger 25, and the cap screw 33 similarly is screwed in y of an inch beyond the point at which the red light is turned on and against the spring pressure of the plunger 26'. The device is then ready for use.

In the operation of such a pulp-treating machine with this indicator the bearing housing 12, rotor shaft and rotor are first moved in opposite direction (to the left) until the green signal light shows. This indicates that the spacing between the attritioning surfaces is greater than /s of an inch. The rotor should always be backed off from the stationary cooperating attritioning element to this extent before the start of each operation or of each batch operation not only to permit adequate washing of the attritioning elements but also to prevent an excessive load on the motor at the start which would occur if the motor were first started with the attritioning elements very close together. In order to prevent inadvertent starting of the motor with the attritioning elements closer than the predetermined of an inch, an optional solenoid switch may be added to the control assembly, as indicated in broken lines at 48 in Figure 7. Such a switch would be included in the starting circuit 49-50 to the motor and would be kept open unless and until the signal circuit through the (green) signal light 35 had been closed. In other words, with this optional addition, it would not be possible to start the operating motor until the rotor had been backed off from the stationary cooperating element a distance at least greater than the predetermined A; of an inch.

After the motor has started operating and the clearance between the attritioning elements is subsequently reduced, as desired, the green light will be turned off and the amber light will be turned on when the clearance is reduced to A; of an inch. When the spacing becomes reduced to .422 of an inch, the red light will show in place of the amber light, warning the operator that the two attritioning surfaces are now very close together. If desired, the closing of the switch to the red light could also be made to operate a relay to break the circuit to the motor by which the adjusting movement of the bearing housing 12 and the rotor shaft is accomplished, if a motor is employed for this purpose.

While the above settings of A3 of an inch and & of an inch are given as an example of the probable settings in a pulp-treating machine of the type mentioned, these settings can of course be easily varied by adjustment of the screws 32' and 33 as specifically required.

Assuming further that, after an extended period of operation of the pulp-treating machine, some wearing of the surfaces of the attritioning elements is believed to have taken place and it is desired to correct the indicating device to compensate for such wear, the bearing housing 12 and the rotor shaft are again moved (to the right) when the pulp-treating machine is not operating, until the attritioning surface of the rotor is brought into actual contact with the attritioning surface of the cooperating stationary member in the pulp-treating machine. In doing this, if there has been any appreciable wear of the attritioning surfaces, the movement of the rod 14 (to the right) will not only bring the sleeve 27 against the end 18' of the member 18 but will force the sleeve 27 to he slid relatively with respect to the rod 14 a distance corresponding exactly to the amount of wear which has taken place on the attritioning surfaces. This automatic adjustment of the sleeve 27 on the rod 14 will again enable the indicator to show the correct actual spacing between the two attritioning surfaces during the operation of the pulp-treating machine, in the manner previously described.

From this description and explanation it will be readily understood how this position indicator may be employed similarly in other installations wherein the careful adjustment of a longitudinally adjustable element is to be indicated and controlled. Minor modifications, including additional limit switches, might be made in the indicator without departing from the prnciple of the invention, but the construction shown and decribed is considered the preferred manner of carrying out the invention.

I claim:

1. In combination with an axially movable shaft-bearing assembly having an outwardly extending engageable element, a position indicating device for said bearing and shaft, said device including a stationary housing mounted adjacent said bearing assembly, a push rod slidably supported in said housing and parallel to the axis of said bearing assembly and shaft, one end of said rod engaging said element, spring means holding said rod against said element while enabling said rod to be moved against the force of said spring means upon axial movement of said bearing assembly and shaft, a pair of stationary supports mounted in said housing adjacent said rod, a sleeve carried on said rod, means normally holding said sleeve against relative movement with respect to said rod, 21 pair of supports on said sleeve, a pair of switches secured on one of said pair of supports respectively, a pair of adjustable actuators for said switches respectively on the other pair of supports, said switches and actuators so arranged that movement of said rod and sleeve a predetermined extent against the force of said spring means will cause a first switch to be actuated and continuation of the movement of said rod a predetermined extent will cause the second of said switches to be actuated, the extent of movement required in each case being determined by the setting of the respective adjustable switch actuator, and a stop limiting said movement of said sleeve and therewith of said supports on said sleeve after said switches have been actuated, whereby further movement of said rod against the force of said spring means when said sleeve has contacted said stop will automatically cause the position of said sleeve on said rod to be ad justed.

2. In combination with an axially movable-shaft hearing assembly having an outwardly extending engageable element, a position indicating device for said bearing and shaft, said device comprising a stationary housing mounted adjacent said bearing assembly, a push rod slidably supported in said housing and parallel to the axis of said bearing assembly and shaft, one end of said rod engaging said element, a spring in said housing engaging the opposite end of said rod and holding said rod against said element while enabling said rod to be moved against the force of said spring upon axial movement of said bearing I assembly and shaft, a pair of stationary supports mounted ment of said rod a predetermined extent will cause the second of said switches to be actuated, the extent of movement required in each case being determined by the setting of the respective switch-actuating screw, and a stop limiting said movement of said sleeve and therewith of said supports on said sleeve after said switches have been actuated, whereby further movement of said rod against the force of said spring when said sleeve has contacted said stop will automatically cause the position of said sleeve on said rod to be adjusted.

References Cited in the file of this patent UNITED STATES PATENTS Smith Feb. 7, 1939 Progress July 29, 1952

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