US1267130A - Power lifting mechanism for saw-trimmers. - Google Patents

Description

I. L. SKEITH 81 W. B. BURROWS. POWER LIFTING MECHANISM FOR SAW TRIMMERS. APPLiCATION FILED AUG.I8, I910. 1,267,130.

Patented May 21, 1918.

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y m .52 4 l I 5/ F2; 12. 61 a: h 1 6'0 51 1 I M/flesses zyrw' l. L. SKEITH & W. B. BURRLOWS. POWER LH-HNG MECHAHSM EUR SAW TRIMMEHS.

APPLICATION FIL'D AUG. I8, 1910. 1,267, 1 30. Patented May 21, 1918.

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- IZorney I. L. SKEITH & W. B. BUHROWS. POWER LIFTING MECHANISM FOR SAW TRIMMERS APFLICAT'ON FILED AUGIB. 9K0- 1,267,130.

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Witnesses: D

Patented May 21, 1918.

I. L. SKEITH & W. B. BURROWS. POWER LIFTING MECHANISM FOR SAW TRIMMERS.

APPLICATION FILED AUG. I8. 1910. 1,267,130. atented May 21, 1918.

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UNITED STATES PATENT OFFICE.

ISAAC L. SKEITI-I AND WILLIAM B. BURBOWS, OF VANCOUVER, BRITISH COLUMBIA, CANADA, ASSIGNORS TO SUMNER IRON WORKS, OF EVERETT, WASHINGTON.

Specification of Letters Patent.

Patented May 21, 1918.

Application filed August 18, 1910. Serial No. 577,855.

To all whom it may concern:

Be it known that we, ISAAC L. SKEITH, a subject. of Great Britain, residing at Vancouver British Columbia, Canada, and WIL- LIAM Bmmows, a citizen of the United States, residing at Vancouver, British Columbia, have invented a new and useful Imrovement in Power Lifting Mechanisms for S KWTIlHImBIS, of which the following is a specification.

Our invention relates to an improvement in power liftin mechanisms for saw trimmers and comprises the novel parts and combinations of parts which will be hereinafter described and particularly pointed out in the claims.

The object of our invention, broadly stated, is to improve and simplify the construction and operation of such devices.

Specifically, our object comprises a construction such that valves controlling the admission and exhaust of air from and supply of air to the lifting cylinders, are placed directly upon the cylinders so that the clearance is minimized and such valves operated from a distant point b a mechanical connection. By this plan the lar e waste of air caused by the necessity for filling the pipes extending from the cylinders to the central control point every time the saw is lifted, is avoided. y

, Another specific object of our invention is to provide automatic means, controlled by the valve-controlling mechanism, whereby when a saw is lifted it will be prevented from droppin until the controlling mechanism has been placed in release position, even should the air pressure entirely fall. This comprises a mechanical catch controlled by the means employed for setting the valve so that it and the valve functionally agree.

Our invention also comprises specifically, a construction of operating levers by which each individual saw may be raised or lowered as desired and, in connection with this, a master lever to which any number of individual levers may be connected for simultaneous operation as desired.

Our invention further specifically comprises a novel construction in the; means employed for sup ortmg and swinging the saw into and out o cperatlon.

The further objects of, car invention will be disclosed by a study of the specifications and claims terminating the same.

In the drawings we have shown our in- IZention embodied in the form now preferred y us.

Figure 1 is longitudinal section throu h one of the pneumatic cylinders employed or controlling a saw.

Fig. 2 is a section on the broken line X of Fig. 1.

Fig. 3 is a section on the line Y Y of Fig. 1.

Figs. 4 and 5are, respectively, side and end elevations of the bank of controlling levers.

Figs. 6 and 7 are, respectively, side and edge elevations of one of the individual saw controlling levers.

Fig. 8 shows in plan and diagrammatically, the general arrangement of the parts and the connection with the" central controlling station.

Fig. 9 shows the arrangement of the entire apparatus in side elevation.

Fig. 10 is a plan view of one of the frames carrying a saw.

Fl 11 is a side elevation of the swinging saw frame.

Fig. 12 is an end view of the three-armed lever which operates the valve.

Figs. 13 and 14 are, respectively, plan and elevation of catch-releasin cam or tappet.

Fig. 15 is a. side elevation of the spring catch for the master lever.

It has been common, heretofore, to control a bank of trimmer saws by supplying the individual frames, which each carries one of the saws, with a pneumatic cylinder so connected; thereto that the saw may be lifted into or out of operating position by admitting air to such cylinder. In such devices the valves] for t e various cylinders have been located at the central controlling point, which point must necessarily be at some distance from the cylinders. Such method means that whenever a cylinder is thrown into operation, the pipe, extending from the central oint of control to the cylinders, must be lled with air under pressure, which air is not essential to the proper action of the piston but simply serves to fill the pipe and communicate t e pressure, and is wasted every time the cylinder is put into use. As a result there is a large and unnecessary waste of compressed air, making it necessary to employ an air compressor of much larger capacity than would be required if this excessive clearance could be eliminatcd.

In our present invention we have placed the valves directly upon the cylinders, so that the clearance between the valve and the cyinder is almost entirely eliminated, and then control these valves bymechanical connection with the distant oint of control. This results in a materia saving in the amount of comfressed air required.

In devices 0 this character it is customary to have the saws mounted in swinging frames so that the saw will drop by gravity into operating position and Wlll be lifted out of operating position by the action of the cylinder thereon.

We have provided means whereby when any individual saw frame is lifted out of operating position, a mechanical catch will be automatically thrown into acting position and so held until the regular controlling mechanism for this saw is placed in release osition, so that if the pressure in the cylin er should drop from any cause, such for instance as the stoppage of machinery, the saw will not drop into operative position until such mechanical catch has been released. The use of this catch prevents the belts by which the saws are operated from being strained at their maximum tension when the saws are not in use, which objection applies to such devices as are not posi-' tively held out of operative position when the ressure in the cylinder is removed.

e have also provided means for operating the cylinder valve from a distance, such as will permit the connection of the operatin means thereto at any angle desired.

n the drawings Fig. 1 shows the longitudinal section of the cylinder with the valve and the means for operating the same. The cylinder 1 is single acting, that is, the power the piston to move it in one direction only, which as shown is during the upward stroke. The piston 2 may be of any suitable or desired construction.

The cylinder is provided with an inlet port 10, located at the extreme lower end of cylinder, and an exhaust port 1.1 located some little distance above the lower end of the cylinder and so thatit will be covered by the piston in its downward stroke before it can strik the lower head. In this way a certain amoiggriizuir contained in the cylinder is trapp (1 serves as a cushion to prevent the piston from striking hard against the lower end of the cylinder.

To prevent dangerous striking of the piston against the upper cylinder head, we

place the relief port 17 a short distance below the cylinder head where it will be covered by the piston before finishing its stroke thus trapping enough air to cushion the piston. By controlling the size of this port the rate of upward movement of the piston may be controlled, the small port acting to delay the escape of the air.

The piston rod 20 extends through the lower end of the cylinder and is connected with the rod 21 which is in turn secured to the swingin saw frame either directly or by means 0 interposed mechanism. As shown, the connection consists of a turnbuckle 21 and rod 25.

We have provided means by which the saws will be mechanically locked and held in raised position in case the pressure in the cylinders is drop ed below that necessary to support them. he means preferred and herein shown is as follows:

Upon the lower end of the piston rod 20, which projects from the cylinder, is secured a disk or cam 23 the periphery of which is of conical shape with the base downward. We have shown this as being a part of the crosshead or pivotal connection with the rod 21, although this is not an essential feature. The lower surface 22 of this disk is concave near its edge so as to more securely engage with the point of the locking hook. This hook is pivoted at 40 between ears beneath and forming a part of the cylinder. The up er, engaging surface 41 of the hook is slig tly recurved so as to cooperate with the curved under surface of the disk 22 and thereby assure against release, once they are brought into engagement except by the positive action of the releasin mechanism. The surface 42 of the side 0 the hook extending below the engaging surface 41, and facing toward the disk 23 is inclined in such a way that it will cooperate with the inclined or coned peripheral surface of the disk, so that the disk in raising will push the hook outward until it has passed the same, whereupon the hook will swing toward the piston rod under the influence of gravity, the point 41 swinging beneath said disk so as to prevent its falling until the hook has been positively thrown outward.

At its upper end the hook 4 is provided with a side extension having its end surface 43 so inclined and positioned as to engage with the eccentric or cam disk 32 carried by the lower end of the valve 3. When the valve 3 is moved downward into the admission position, the disk 32 frees the book so that 1t may drop by gravity into its locking position.

The valve 3, in the form shown and preferred, is a piston valve, consisting of a round bar which is reduced in area attwo pomts 30 and 31, so as to provide a suitable area for the passage of steam between the supply chamber 12 and the port 10, and also be carried by into operative position the belts between the two exhaust ports 11 and 13. The position of the valve shown in Fig. 1 is that in which the compressed air is in communication with the interior of the cylinder. Compressed air from the suppl chamber 12 passes around the section 30 0 the valve to the port 10, and thence directly into the cyl inder, acting to raise the piston to the top of the cylinder.

The lower end of the valve 3 projects through the walls of the cylinder and has a tappet secured thereto, this as shown consisting of an eccentric or cam disk 32, which, in the admission position of the valve, is engaged by that portion of the inclined surface 43 of the hook, which is nearest the pivot 40.

If now the valve be raised, the first result will be that the movement of the tappet disk 32 over the inclined surface 43 of the hook will swing the point 41 from beneath the disk 23 thus leaving the piston free to fall.

The disk 23 is slightly above the point 41 of the hook when the piston is in its uppermost position, so that the weight of the piston and the load carried thereby will never the hook, unless the air pres-- sure should dropr below that required to carry the load. he swinging of the hook clear of the disk does not, therefore, require the use of any material force.

The next result caused by the raising of the valve is to cut oil the suppl of compressed air to the cylinder by c osing the port 10. The valve is given suflicient lap that exhaust does not commence until after the valve has moved a certain distance after closing the admission port. This gives sufficient travel that the hook point 41 is clear of the disk 23 before exhaust commences. This takes place through port 11, about the reduced section 31 of the valve and through port 13.

In order to control therate of exhaust and prevent the rapid dropping of the piston we provide what may be called a throttle bolt 110, which assesthrough the wall of the cylinder and into the exhaust ort 11. This bolt is clearly shown in Fi It is evident that by screwing this bo t inward it will reduce the area of this exhaust ort, which reduction of area may be carried to such a point as will throttle the exhaust so as to make the rate of fall of the piston whatever desired.

he saws are mounted upon swing frames in such a manner that when the saw is raised out of o erative position the belts are slackened, an when they are dro ed are tig tened, consequently if the saws be maintained in their raised position, in which the belts are slackened, by positive mechanical meansin which position the belts are freed from strain, it will. not be necessary to cut and tighten them at frequent intervals, and

they will therefore last much longer. These mechanical locking means above described are controlled directl by the action of the valves controlling t e power mechanism, being freed as the first step of the movement of the valve mechanismv to its release position.

To the upper end of the valve 3 which extends to the exterior of the valve chamber is secured a rod 33 by which the valve is operated. We have provided a means for operating these valves which will permit of leading the actuating wires in any angular direction desired. These means comprise an arm which is pivoted in direct line with the axis of the valve and upon which is mounted a double elbow or three-armed lever, one end of which is connected with valve rod 33, the pivot connection being in line with the axis of the valve and in line with the pivot of this swinging arm.

At the end of the cylinder opposite that which contains the valve and in line with the axis of this valve is mounted a pivot bolt 50 upon which is pivoted an arm 5. This arm is preferably made hollow and, as shown, between the sides thereof is placed a double elbow'or three armed lever 6, one arm 60 being pivotally connected with the upper end 0 the rod 33 and of such length as to move in a small are which does not materially diverge from an exact alinement with the axis of the valve.

The arms 62 and 63 of these levers extend oppositely from the central pivot 61 and are provided with the means at each end, consisting of holes or projecting pins, 64, to which may be connected whatever means are employed for communicating the motion thereto from a distant point.

The means preferred by us for this urpose consists of small piano wires, w ich may be conducted around corners in any course desired by means of simple guide pulleys. We prefer to provide t e swin stops which will e as to limit P 85 screwed osition ing pivot arm 5 with engaged by the elbow lever 6, so its motion in any direction. Such shown, consist of set screws 51 through a portion of the lever in a to be engaged by arms 62 and 63 of Two wires 52 and 53 are connected with the opposite arms of each of these levers and lead to the central control int.

-At a central control point is provided a batik of controlling levers, one for each cylinder employed, which levers are each connected by means of these wires with its respective lever 6 carried by the cylinders. We also provide a master lever and means b which any number of individual levers may be connected so as to be operated by and in unison with the master lever.

These operating levers ars shown in Figs.

ever 6.

the master lever are pivoted upon a common shaft 7, which shaft is supported by brackets or in any other suitable manner. The individual levers 71 are provided with arms 72 which extend oppositely from the pivot, and to the outer ends of which are connected the wires 52 and 53, which extend to the lovers 6 mounted upon the different cylinders. The levers 71, by which the individual saws are operated, are mounted loosely upon shaft 7 Secured to the shaft 7, preferably at each end thereof, are master levers 8. These master levers are also connected by a rod 80 which extends throu h slots 73 formed in each one of the individual levers 71. These slots 73 are of suflicient transverse length to permit of each lever being operated so as to control its valve, without mov in the master lever.

hese slots in the lever may be made of a permanent character closed at each on We prefer, however, to make them open at one end and then provide means, for instance the pivot latches 74, by which this and ma be made open or closed as desired. Suc levers as have their latches 74 in position to' close the slots will be operated simultaneously by movement of the master lever in either direction, while such levers as have their latches dropped, so as to leave these ends of the slots open, would not be operated by movement of the master lever in one direction. It often happens in operating a bank of trimmer saws that it is desired to operate certain combinations of saws simultaneousl The aliove expedient makes it possible for the operator to connect any combination as is desired for simultaneous operation by the master lever and to vary this combination at any time desired. By moving the master lever in the direction in which all the slots 73 are permanently closed, all the saws will be raised while movement in the opposite direction will lower only those saws whose individual lovers have their latches 74 in position to close their slots.

In operating a master lever this must be given a movement sufficient to engage the rod 80 with the end of the slots in the individual levers before any movement of the valve is started. The master lever, there fore, has a greater swing than the individual levers.

In Fig. 5-the lever 71 is shown in full lines in one extremeposition and by dotted lines in the other extreme position. The master lever is shown in full lines in its ino erative or central position and by dotted ines in both extreme or operating positions. The master lever is provided with means by which it is held in central position until it is desired to move it; such means as shown consisting of a pin 81 projecting laterally so that when the frame 9 is raised from the lever and a spring catch 82 having a recess or hollow 83 adapted to engage such pin and furnish'sufiicient resistance to prevent movement of the lever unless some little power is applied thereto.

In Fig. 8 we have shown a numbe of cylinders 1 connected by means of unions 1 and short pipe sections 15, with a main supply pipe 16. This makes a very simple and cheap method of supplying the air to these cylinders as compared with the plan having separate supply pipes from the central control station to each cylinder. We also show a series of wires 52 leading from these cylinders to a central controlling station A. This view is very diagrammatic in character.

In Fig. 9 is shown, in elevation, the entire apparatus. The wires 52, 53, may be led about wheels or pulleys 5a to the central controlling station 103 where they are connected with the arms 72 of the individual controlling levers. Each wire should have a turnbuckle 55 therein so that its length maiy be adjusted.

11 Figs. 10 and 11 we have shown a plan for mounting saws in swinging frames which permit of adjustment to take up the stretch occurring in the driving belt, as well as for alining the saw so as to get exact spacing between the saws of the set. This mechanism comprises a frame 9 in one end of which a saw, 100, is mounted, which frame is pivoted at 90 to arms 91 which are pivoted at their upper ends by pivots 92 to brackets 93 secured to the end timber 94.

The driving pulleys 95 for all the saws of the set are mounted upon a shaft 96 which is journaled to the timber 94. To the lower pivot 90 of this device is secured eye bolts 97, which pass throu h iopenings in the timbers and are provi ed with nuts 98, by the adjustment of which these eye bolts may be projected or withdrawn as may be necessary for lengthening the belts, or adjusting the position of the saw relative to saws. The lateral adjustment or alinement of the saws is varied by unequal adjustment of the bolts 97. Adjustment of the bolt 97 at one side of the frame without any adjustment of the corresponding bolt upon the other side would swmg the outer end of the saw frame laterally.

' The shaft 96 is higher than the pivot 90 it will tend to slacken the belt 99 by which the saw is driven. When the frame is lowered to lace the saw in operative position the belt 13 tightened. As the saws occupy the raised position more time than they do the lowered the belts is thereby much Weclaim as our invention 1. A lifting mechanism for trimmer saws,

comprising a series of cylinders and pistons the other I therein, each connected with its individual saw, a valve carried by each cylinder and. adapted to control the piston therein, a series of levers and connections therefrom, each to its articular cylinder valve, each of said levers iiaving a transverse slot, a master lever, and a rod carried by said master lever and adapted to lie in said slots of the individual levers, whereby the individual levers may be operated separately and a series of said individual levers may be operated simultaneously by the master lever.

2. The combination with a series'of saws, of saw-lifting mechanism comprising a corresponding series of compressed air cylinders each having its piston connected with its saw, valves mounted adjacent to the cylinders, respectively, and each controlling the piston-actuating fluid for its cylinder, and manually operated means at a distant station for controlling all said valves.

3. A lifting mechanism for saw trimmers, comprising a series of cylinders and pistons therein each connected with its individual saw to raise and lower the same, valves mounted adjacent to said cylinders, respectively, and controlling the fluid for actuating the corresponding pistons, means for mechanically transmittin power from a distant station to each of said valves, and manually operated selective devices at said station for governing the transmission of power to the several valves.

4. A lifting mechanism for trimmer saws, comprising a series of cylinders and pistons therein, each connected with its individual saw, a valve carried by each cylinder and adapted to control the piston therein, a series of levers and connections therefrom, each to its particular cylinder valve, and a master lever whereby the saws may be raised and lowered at will individually or collectively.

5. A lifting mechanism for trimmer saws, comprising a series of cylinders and pistons therein, each connected with its individual saw, a valve carried by each cylinder and controlling the movement of the piston therein, a series of distant controlling levers,

a connection from each of said levers with the valve of its particular cylinder, said levers each having a transverse slot provided with means whereby one end of said slot may be closed or opened at will, and a master lever whereby thesaws may be raised and lowered at will individually or collectively. 6. A lifting mechanism for trimmer saws, comprising/a series of saws, means for supporting and swingin the saws into and out of posltion indepen ently of each other, a series of operating levers corresponding with the saws, and a master lever whereb the saws may be raised and lowered at wi l individually or collectively, a cylinder with piston mounted above each saw, a valve upon each cylinder for controlling the piston and connected by actuating wires to their respective levers located at a distant point of control.

7 A lifting mechanism for trimmer saws, comprising means for moving the saws into and out of operating position, a separate cylinder and piston for each saw, and a controlling valve mounted on each cylinder, a series of operating levers and a master lever located at a distance from said cylinders, and mechanical valve-operating connections, as a wire, extending from each operating lever to its respective Valve.

8. In a lifting mechanism for trimmer saws, a cylinder and piston therein for each saw, said cylinders having the seats for the fluid controlling valves formed integrally therewith, a valve for each cylinder coacting with the seat for said cylinder, and means for controlling said valves from a common point.

9. In a lifting mechanism for trimmer saws, a separate cylinder and piston therein for each saw, said cylinder havin a valve seat formed therein, a valve in said seat, a valve operating lever mounted upon the cylinder to swing upon double pivots having axes which are at substantially right angles, distant operating means, and transmitting mechanisms connecting said operating means with the cylinder-carried, valve-operating levers and radiatin from a common point to the various cylin ers.

10. In a lifting mechanism for trimmer saws, a separate cylinder and piston therein for each saw, each cylinder having a valve seat formed thereon, a valve seating u on said seat, and a valve-controlling mem er carried by the cylinder, said valve-controlling member being automatically adjustable to conform to the lead of a transmission member throughout a wide angular range.

11. In a lifting mechanism for saw trimmers, the combination with separate actuating mechanisms for each saw, each of said actuating mechanisms comprising a cylinder and piston, a valve controlling the actuating fluid and a means for controlling said valve, all mounted directly upon the cylinder as a frame, of a corresponding set of distant secondary controlling mechanisms, one for each cylinder, transmission members connecting said secondary controlling members with the primary valve-controlling members carried by the cylinders, a master controlling member associated with said set of secondary controlling members, and means for optionally combining said secondary controlling members for simultaneous o ration by said master member in any com ination desired, without affecting their capacity for independent and separate action.

12. A shifting mechanism for trimmer saws comprising a series of saw shifting cylinders, a valve seated in the body of each of said cylinders and controlling the supply of motive fluid, each for its respective cylinder, and a selective operating mechanism for said valves located at a common point.

13. A shifting mechanism for trimmer saws comprising a series of saw shifting cylinders, a valve seated in the body of each of said cylinders and controlling the supply of motive fluid, each for its respective cylinder, a valve shifting mechanism for each cylinder pivotally mounted upon that cylinder to automatically adjust itself to an actuatin connection from variable an les, manna ly controllable actuating mem ers grouped at a common point and transmitting members connecting said manually controllable members with the valve shifting mechanism carried by the cylinders, and means for combining said manually controllable members to actuate any desired combination thereof as a unit.

14. A shifting mechanism for trimmer saws comprising a series of saw shifting cylinders, a valve seated in the body of each of said cylinders and controlling the supply of motive fluid, each for its respective cylinder, a valve-shifting mechanism for each cylinder pivotally mounted u on that cylinder to automatically adjust itself to an actuating connection from variable angles, manually controllable actuatin members grouped at a common point an transmittin members connecting said manually contro lable members with the valve-shifting mechanism carried by the cylinders.

15. A lifting mechanism for trimmer saws comprising a cylinder, a piston therein, a piston rod, a connection from the exterior end of said rod to the saw frame to lift it, a dog engaging member or catch carried by the outer part of the piston rod, a dog pivoted to the cylinder and adapted to swing under said catch member by gravity, and means for releasing said dog from the catch actuated by the valve whlch controls the supply of actuative fluid to the cylinder.

16. In a lifting mechanism for trimmer saws, a cylinder, a piston therein, a valve controlling the actuative fluid, means connectingthe piston with the saw, a mechanical catch comprising one member carried by the cylinder and another connected with the piston and adapted for automatic lockin engagement, and means for operating %1oth valve and catch from a distance.

17. In a lifting mechanism for saws, a cylinder, 9. piston therein, a valve controlling the actuative fluid, means connecting the piston with the saw, a mechanical catch comprising one member carried by the cylinder and another connected with the piston and adapted for automatic locking engagement, means for operating the valve from a distance, and means whereby the movement of the valve into exhaust position will release the catch.

18. In a lifting mechanism for trimmer saws, a fluid pressure cylinder, a piston therein, a piston rod, a valve carried directl upon that end of the cylinder from Whic the piston rod projects, a locking catch automatically engageable to hold the piston when raised and comprising one member carried by the piston rod and another carried by the cylinder, one of said catch members and the valve having parts engaging to release the catch when the catch is placed in release position.

ISAAC L. SKEITH. WILLIAM B. BURROWS.

Witnesses:

Sonnrnnn Dorm, C. DUDLEY Lnn.

trimmer

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