US3032083A

US3032083A - Device for adjusting the set mechanism of a sawing rig

Info

Publication number: US3032083A
Application number: US6893A
Authority: US
Inventors: Thomas J Stephens; William J Stephens
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-02-05
Filing date: 1960-02-05
Publication date: 1962-05-01
Anticipated expiration: 1979-05-01

Description

y 1962 T. J. STEPHENS ETAL 3,032,083

DEVICE FOR ADJUSTING THE SET MECHANISM OF A SAWING RIG Filed Feb. 5, 1960 A 5 Sheets-Sheet l INVENTOR. 77/4/1045 STFPflE/VS BY7/ ff y 1962 T. J. STEPHENS ETAL 3,032,083

DEVICE FOR ADJUSTING THE SET MECHANISM OF A SAWING RIG Filed Feb. 5, 1960 3 Sheets-Sheet 2 1L 9 Q -10 m INVENTOR.

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y 1962 T. J. STEPHENS ETAL 3,032,083

DEVICE FOR ADJUSTING THE SET MECHANISM OF A SAWING RIG Filed Feb. 5, 1960 3 Sheets-Sheet 5 Moi/7 trite States This invention relates to saw mill equipment and is particularly concerned with an improved arrangement for operating the set mechanism of a sawing rig so that boards of the desired width can readily and rapidly be sawn from a log.

Heretofore, set mechanisms have generally been operated manually and this, of course, is occasioned by loss of valuable operating time of the sawing rig. Motorized devices for operating the set mechanism of a sawing rig are known but heretofore such mechanisms have tended to involve the use of rotating electric motors or the like which develop considerable inertia in operation whereby the termination of the adjustment tends to be less precise than desired whereby the boards have some tendency to vary in thickness.

Accordingly it is a primary object of the present invention to provide a greatly improved automatic adjusting mechanism for the set mechanism of a sawing rig.

A still further object of this invention is the provision of automatic means for adjusting the set mechanism of a sawing rig in which the adjustment can readily be varied to provide for different thicknesses of cut.

A still further object of this invention is the provision of an automatic arrangement for adjusting the set mechanism of a sawing rig which can readily be incorporated in existing equipment thus permitting the arrangement to be manufactured and sold not only for incorporation in new equipment but as an auxiliary to be added to equipment already in use.

These and other objects and advantages will become more apparent to the drawings in which:

FIGURE 1 is a perspective view showing the principal components of a sawing rig having a set adjusting mechanism according to the present invention incorporated therewith;

FIGURE 2 is a section indicated on line 2-2 on FIG- URE 1 showing a portion of the set adjusting mechanism according to this invention;

FIGURE 3 is a sectional view indicated by line 3--3 on FIGURE 1 showing the structure by means of which the table of the saw rig is adjusted laterally to provide for the desired thickness of cut;

FIGURE 4 is a sectional view indicated by line 44 on FIGURE 2 showing the several adjustable cams by means of which the automatic set adjusting mechanism is controlled; and

FIGURE 5 is a more or less diagrammatic representation of the set adjusting mechanism according to this invention and the control circuit pertaining thereto.

Referring to the drawings somewhat more in detail,

FIGURE 1 more or less diagrammatically illustrates a sawing rig wherein there is a reciprocating platform or carriage set on rails 12 resting on a floor or other Patented May 1, 1962 boards 18 of whatever thickness desired can be taken from the log.

The platform It) is reciprocated by any well known means such as by a cable 20 attached thereto passing about sheaves or pulleys 22 located beneath the plane of the platform 10 and with the cable being driven by a reversible drive such as a reversible electric motor. The travel of the platform can be controlled by the sawyer, or limit switches may be provided which determine the limits of travel of the platform.

Mounted on platform 10 is a log supporting means of a structure consisting of two or more frames, or knees 24 which are guided in tracks or headblocks 26 for movement laterally of the platform 10 so that a log supported on the frames, or table, can be adjusted laterally of saw blade 16. The frames 24 each comprise upstanding portions 28, each of which has an adjustable gripper or dog 3i"; at the upper end so that when a log is positioned on the frames it is provided with a b ack stop and also with gripping means for holding it firmly in place on the frame.

Adjustment of the back stops can be accomplished by the levers 32 to accommodate the frame to logs of different size and likewise the gripping members 30 can be adjusted not only vertically but in the fore and aft directions as well. The log supporting table consisting of the frames 24 is adjustable laterally of the table 10 by a mechanism that will be seen in FIGURES 1 and 3. This mechanism consists of a setshaft taking the form of shaft 34 extending longitudinally of the table and through the tracks 26 beneath the frames 24. Each frame 24 has attached to its underside a rack 36 which is engaged by a pinion 38 keyed to shaft 34. It will be evident that rotation of shaft 34 will adjust the frames 24 in unison whereby a log supported on the table which consists of the frames 24 will be moved in parallelism with itself laterally of platform 10.

A motor (not shown) may be provided for driving shaft 34 in its opposite directions and the shaft directly driven by such motor, said shaft being indicated at 40, is preferably connected with shaft 34 by means of torsion spring 42. This permits adjustment of shaft 34 by means other than the said motor without rotation of shaft 40 and also permits a spring bias to be maintained on shaft 34 so that it can be returned to a starting position automatically after it has been adjusted from that position by the means other than the said adjusting motor.

Manual means of a conventional nature are provided for adjusting the shaft 34 and this may take the form of a lever 44 mounted for oscillation about the axis of shaft 34 and carrying a pawl adapted for driving engagement with the periphery of a gear-like member 46 attached to the shaft 34. This pawl will drive gear-like member 46 in the direction of rotation necessary to inove frame 24 to advance log 14 toward saw blade 16; Such mechanism would also include a lock pawl (not shown) to hold the gear-like member 46, and, therefore, shaft 34 and frames 24 in their adjusted positions.

Means are provided as, for example, a foot treadle 48 for releasing the pawls so that the frames 24 can be moved to retracted positions when a new log is to be placed in the saw mill.

According to the present invention a novel automatic adjusting mechanism is provided which takes the form of a second gear-like member 50 mounted on shaft 34 in spaced relation with the previously referred to member 46. There is also provided a lever 52 which is adapted for actuation about the axis of shaft 34 and which spans member '50. A pawl 54, best seen in FIGURES 2 and 5 is carried by lever 52 so as to be engageable with the periphery of gear-like member 50. Member 50 and pawl 54 thus form a ratchet mechanism which will drive shaft 34 in one direction only.

The treadle 48 is so arranged that the operation thereof will withdraw pawl 54 from the periphery of member 50 at the same time that the pawl pertaining to lever 44 is withdrawn from the periphery of member 50 and at which time any latch pawls engaging the members are also withdrawn thereby leaving shaft 34 free for rotation in the opposite direction.

According to the present invention lever 52 is oscillated by the combination of a single acting fluid motor and a return spring. This motor comprises a cylinder 56 pivotally supported at 58 at the end opposite lever 52. A

piston or ram having a rod portion 60 is mounted in the cylinder and the rod portion 60 is pivoted at 62 to the upper end of lever 52. Springs 64 are connected between the upper end of lever 52 and a stationary point 66 adjacent the back end of cylinder 56.

It will be evident that a supply of pressure fluid to the left end of cylinder 66 via conduit 68 will cause rightward movement of rod 60 and this will bring about clockwise movement of lever 52 about the axis of shaft 34 whereby pawl 54 will drive member '50 clockwise and this will also drive shaft 34 clockwise and cause frames 24 to be adjusted toward saw blade 16. Upon release of pressure from the left end of cylinder 56, springs 64 will cause return movement of rod 60 and lever 52 to their starting position which is indicated in FIGURE 2. The control of the movement of rod 60 is accomplished by a plurality of limit switches and adjustable cams mounted within a control box 70. The box 70 is supported as by being welded to the end part 72 of cylinder 56. Within the control box and extending transversely thereof is a shaft 74 to which is fixed a gear 76. Gear 76 extends through a slot in the bottom wall of the control box so as to mesh with a rack 78 that is attached to rod 60 as by being welded by a block 80 which in turn is welded to a collar 82 fixed to rod 60.

The rack 78 rides in a slot provided in end member 7 72 of the cylinder so that as rod 60 reciprocates the rack 78 will reciprocate therewith and cause rotation of gear 76 and the shaft 74 on which it is mounted.

Also mounted on the shaft are a plurality of earns 84 which are preferably attached to the shaft by means of set screws so that they can be adjusted angularly. Pertaining to each cam 84 is'a limit switch 86. At this point it will be evident that by angularly adjusting the earns 84 on the shaft 74 the cams can be caused to engage the respective limit switches at any desired point in the travel of rod 60 in its rightward direction. This, in turn, predetermines the swinging movement of lever 52 and thus predetermines the adjustment of member 50 and shaft 34 and the movement of the log supporting table consisting of the frames 24. The cams and limit switches thus provide means for controlling the adjustment of the set mechanism of the sawing rig.

At this point it might be observed that an indicator is provided for indicating the position of the log supporting table and the amount of adjustment thereof whereby indications can be had of the position of the log and the size of the boards cut therefrom.

This indicator takes the form of a dial 90 (FIGURE 2) over which a pointer 92 sweeps. Pointer 92 is mounted on a shaft carrying a sprocket which is connected by a chain 94 with a sprocket on shaft 34. By this arrangement pointer 92 W"l always indicate the position of shaft 34.

Turning now to FIGURE 5, this view illustrates the control circuit for the described arrangement. In this view it will be noted that there is a motor which drives a hydraulic pump 102 having its suction side connected to reservoir 104 and its discharge side connected to a pressure conduit 106 leading to the inlet of a reversing valve 108 and to the inlet of a pilot valve 110.

Pilot valve 110 is biased in one direction by a spring 112 and when under the influence of spring 112 it directs pilot fluid to the end of valve 108 that causes shifting thereof into position to interrupt the supply of pressure fluid to conduit 68 and instead to connect conduit 68 to exhaust conduit 114. When solenoid S1 pertaining to the pilot valve 110 is energized the pilot valve shifts and directs fluid to the opposite end of reversing valve 108 so that reversing valve 108 shifts and again supplies fluid under pressure to conduit 68. Energization of solenoid S1 is accomplished by closing of a relay R1. The operating coil for relay R1 has one side connected by wire 116 to power line L1 while the other side is connected by wire 118 to one side of each of the several cam controlled limit switches 86 associated with the several earns 84 mounted on shaft 74 that rotates as the fluid motor reciprocates.

The other side of each switch 86 is connected through a normally open push button 120 with the other side of the line which is indicated L2. It will be evident that closing of any of the switches 120 will be accompanied by the completing of a circuit through the operating coil of relay R1 whereby the relay will close thus causing shifting of the pilot valve 110 which in turn will cause shifting of reversing valve 108 to actuate the fluid motor so that the movable portion as represented by rod 60 will move rightwardly thus causing actuation of shaft 34. Simultaneously, rack 78 moves rightwardly and this causes rotation of gear 76 and shaft 74 and the earns 84 mounted thereon until the cam 84 pertaining to the limit switch 86 that is in circuit with the one of the push buttons 120 which is closed opens the said limit switch. At this time relay R1 will drop out, the push button will be released, and the fluid motor will return under the influence of springs 64 to its starting position.

Due to the relatively light weight and slow speed of movement of the automatic set adjusting mechanism, there is no tendency for the adjusting mechanism to overrun the point at which the controlling cam engages its limit switch and, accordingly, very precise control of the set mechanism can be had by using the device of the present invention.

The push buttons 120 may advantageously be mounted on a panel 122 (FIGURES 1 and 2) or the like which may be supported by bracket means 124 on control box 70. This will locate the svwltches where they are readily convenient to the operator of the saw rig when the platform 10 is in its fully retracted position.

Reference to FIGURES 1 and 2 will show that the structure of the present invention is of a unitary nature with all parts thereof, except the lever 52, pawl 54 carried thereby and member 50, mounted on a base member 126 which can be attached to platform 10 as by bolts or cap screws 128. This platform carries the supporting structure 130 to which springs 64 are anchored and to which the end of the fluid motor is pivoted. The motor 100 and pump 102 are mounted on this platform and the reservoir 104 is carried on the platform in elevated position making it quite convenient to connect the pump with the reservoir and also preventing any air from getting into the hydraulic lines. At the back of base 126 there may be provided uprights 132 that support a panel 134 carrying switch box 136 in which the relay R1 referred to above as well as other electrical components, such as line switches and the like can be mounted.

By providing the base member 126 and supporting the components of the structure of the present invention thereon, it becomes a simple matter to adapt the device of the present invention to existing equipment. For this reason it is proposed that the device he produced not assists only for incorporation in new manufacture but also for use with saw rigs already in operation. 7

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions and, accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

We claim:

1. In a control system for a sawing rig having a reciprocating platform, log supporting knees laterally movable on the platform, and a swingable lever on the platform connected with the knees so movement of the lever in one direction will adjust the position of the knees on the platform while said lever will move in the opposite direction independently of the knees; a reciprocating hydraulic motor connected with the lever energizable for moving the lever in said one direction, a valve movable to energize the motor, electric means energizable to move the valve, a plurality of manual switches each operable when actuated to energize said electrical means, and a limit switch pertaining to each manual switch actuated by the motor during movement thereof operable to make the pertaining manual switch inelfective, said limit switches being arranged for sequential actuation by said motor, said motor being continuously biased in the retracting direction so as to return automatically upon actuation of the limit switch pertaining to the actuated one of said manual switches.

2. In a control system for a sawing rig having a platform, log supporting knees on the platform movable transversely thereon, rack means on the knees, pinion means meshing with the rack means, a shaft on the platform on which the pinion means is carried so rotation of the shaft will move the knees on the platform, a ratchet wheel on the shaft, and an arm swingable on the shaft having a pawl to drive the ratchet wheel in one direction of movement only of the arm; a cylinder carried by the platform, a ram in the cylinder connected to the arm, spring means urging the ram in one direction in the cylinder, a fluid pump, a valve connecting the pump to the cylinder normally positioned to exhaust the cylinder, a solenoid for the valve energizable for shifting the valve to supply pressure to the cylinder to cause the ram to move, a plurality of manual switches each operable when closed to energize said solenoid, a normally closed limit switch in series with each manual switch, a cam for each limit switch, a shaft adjustably supporting said cam, a gear on the shaft, and a rack meshing with the gear attached to the ram so closing of any of the manual switches will be accompanied by movement of the ram and, therefore, of said knees until the limit switch pertaining to the closed one of the manual switches is opened by its cam, said motor being continuously biased in the retracting direction so as to return automatically upon actuation of the limit switch pertaining to the actuated one of said manual switches.

3. In a device for automatically actuating the set mechanism of a sawing rig, said mechanism including an arm movable in one direction to adjust the rig and movable idly in the other direction; a base member, a motor driven pump on the base member, a cylinder connected to the base member, a ram in the cylinder connected to the said arm, spring means connected between the base member and the ram biasing the ram in its retracting direction, a valve connected between the pump and cylinder having a normal position where the cylinder is exhausted and a shifted position where the cylinder is supplied with pressure from the pump, a solenoid operator for said valve, a normally opened relay in circuit with said operator so that closing of the relay will energize the operator and shift the valve, a plurality of energizing circuits connected in parallel and with said relay, each energizing circuit comprising a normally open manually operated push button switch and normally closed limit switch in series therewith, a cam for each said limit switch, a shaft adjustably supporting 6 said cams, and means for rotating said shaft in unison with movements of said ram for sequential actuation of the pertaining one of said limit switches by said cams.

4. In a device for adjusting the set mechanism of a sawing rig, said set mechanism comprising an oscillating arm effective to adjust the rig in one direction of movement only; a base member, a fluid motor connected between the base member and said arm for actuating the arm in its opposite directions, a reservoir for hydraulic fluid on the base member, a hydraulic pump and a drive motor therefor on the base member, conduit means forming a circuit between the reservoir and the pump and the fluid motor, said circuit including a valve for selectively connecting the fluid motor with the pump or with the reservoir, an electric operator for said valve and a control circuit for energizing said operator, said control circuit comprising a plurality of normallyopened push button switches each closable to energize the operator, a normally closed limit switch in series with each push button switch, a cam for each limit switch, a shaft adjustably mounting said cams, a gear on the shaft, a rack meshing with the gear, and means conmeeting said rack for movement in unison with said arm so that upon closing of a selected one of said push button switches, the fluid motor will be energized to actuate the arm until the pertaining one of said limit switches is actuated and opened by its cam, there being a spring biasing said motor in the return direction.

5. In a device for adjusting the set mechanism of a sawing rig, said set mechanism comprising an oscillating arm effective to adjust the rig in one direction of movement only; a base member, a fluid motor connected between the base member and said arm for actuating the arm in its opposite directions, a reservoir for hydraulic fluid on the base member, a hydraulic pump and a drive motor therefor on the base member, conduit means forming a circuit between the reservoir and the pump and the fluid motor, said circuit including a valve for selectively connecting the fluid motor with the pump or with the reservoir, an electric operator for said valve and a control circuit for energizing said operator, said control circuit comprising a plurality of normally opened push button switches each closable to energize the operator, a normally closed limit switch in series with each push button switch, a cam for each limit switch, a shaft adjustably mounting said cams, a gear on the shaft, a rack meshing with the gear, and means connecting said rack for movement in unison with said arm so that upon closing of a selected one of said push button switches, the fluid motor will be energized to actuate the arm until the pertaining one of said limit switches is actated and opened by its cam, spring means biasing said motor in the return direction, there being a shaft comprising a portion of said set mechanism actuated by said arm, and. indicator means for indicating the position occupied by the shaft.

6. In a device for adjusting the set mechanism of a sawing rig, said set mechanism comprising an oscillating arm effective to adjust the rig in one direction of movement only; a base member, a fluid motor connected between the base member and said arm for actuating the arm in its opposite directions, a reservoir for hydraulic fluid on the base member, a hydraulic pump and a drive motor therefor on the base member, conduit means forming a circuit between the reservoir and the pump and the fluid motor, said circuit including a valve for selectively connecting the fluid motor with the pump or with the reservoir, an electric operator for said valve and a control circuit for energizing said operator, said control circuit comprising a plurality of normally opened push button switches each closable to energize the operator, a normally closed limit switch in series with each push button switch, a cam for each limit switch, a shaft adjustably mounting said earns, a gear on the shaft, a rack meshing with the gear, and means connecting said rack for movement in unison with said arm so that upon closing of a selected one of said push button switches, the fluid motor will be energized to actuate the arm until the pertaining one of said limit switches is actuated and opened by its cam, spring means biasing said motor in the return direction, said sawing rig comprising a reciprocating platform, said device being mounted on said platform, there being a panel forming a part of said device positioned so as to be accessible to the operator with the platform in retracted position, and said panel carrying said push button switches.

157,679 Durkee Dec. 15, 1874 8 Palmer Feb. 2, 1904 McDermott Aug. 8, 1905 Niedermeyer Dec. 19, 1905 Martin June 23, 1925 Newson Dec. 14, 1926 Calvert Oct. 14, 1952 Craik May 3, 1955 Elworthy July 7, 1959