US1790802A - Valve fob controlling the travel of tons dogs for sawmill carriages - Google Patents

Description

Feb.'3, 1931. FERR|$ 1,790,802 VALVE FORGONTROLLING THE TRAVEL OF TONG DOGS FOR SAW MILL CARRIAGES Filed July 16, 1929 5 Sheets-Sheet 1 :IEF INVENTOR.

EAV/E ,4 5521741 A TTORNE YS.

Feb. 3, 1931- E. A. FERRIS VALVE FOR CONTROLLING THE TRAVEL OF TONG DOGS FOR SAW MILL CARRIAGES Flled July 16, 1929 3 Sheets-Sheet 2 INVENTOR.

BY E mm: A. PEER/J.

ATTORNEYS.

Feb. 3, 1931 E A. FERRIS VALVE FOR CONTROLLING THE TRAVELLOF TONG DOGS FOR SAW MILL GARRIAGES Filed July 16, 1929 s Sheets-Sheet :5

INVENTOR.

El? VIE A. F'ERR/s.

A TTORNE YS.

Patented Feb. 3, 1931 JUNITEDISVTATES PATENryoF Ic Application filed July 16,

My invention. relates to improvements in valves for controlling the travel of tong dogs for saw mill carriages,and it consists in the combinations, constructions and arrangements hereinafter described andclaimed.

No..286,399 filed June 18, 1928, and in the present application I will structure per se. c An object of my invention is to provide a claim the valve device of thetype described-in which the valve mechanism is extremely simple in con-' struction for the work performed, and in which novel means is provided-for causing the tong dogs to tend tomove toward the face of the knee, i. e. into retract-ed position when these dogs engage with a cant; In this Way the cant is held against theknee, which results in more perfect lumber being cut'from Other objects and advantages will appear as the specification proceeds, and the'novel features of the device will be particularly pointed out in the claims My invention is illustrated in the accompanying drawing forming a part of this application, in which:

Figure 1' is a diagrammatic showing of the tong dogs and an operating valve for regulating the movements of the dogs, the dogs 7 receiving a log;

Figures 2 and 3 are sectional views of remote control valves;

Figure 4 is a vertical section'through the operating valve on line 44-of Figure 1;

Figure 5 is a section along the line 55 of Figure 4; and

Figure 6 is similar to Figure 1, but shows the tong dogs drawnback for receiving a cant.

In carrying out my invention, I'make use of a hammer or top dog 1 mounted upona saw mill carriage In, this dog being raised 1 and lowered by means of a piston rod2 that in turn is connected to a piston 3. The piston is mounted in a cylinder 4 that has a pivnnvinn. FEBRIS, on wEs'rwconcA Iromvm vALvEFon CONTROLLING THE maven or rons noes non SAWMILL cARnIAGns 1929. Serial m svsasa otal mounting at 5 with a lower dog 10. A stanchion 6' has a channel for slidably receiv; ing blocks 16 and 10a, carriedby the tong dogs, and is moved forwardtor backward-in guides 6a'by means of a piston rod? thatcarries a piston'8 mounted in a cylinder9. The

dog 1 cooperates with the dog 10 for holding a log 11 (see Figure 1) or a cant 1111 (see Figure 6). The moving of the stanchion with respect to the knee 7 a moves the tong dog points toward or away from the face ofthe An operating valve indicated generally at 12 has a V plurality of large cylinders 13, 1 4, 15 and'16, shown in Figure 4, connected to the cylinders 4 and 9Iby. pipes. The pipe 17 connects the cylinder 13 with thebottom of the cylinder 4, while the pipe 13 connects the cylinder 14 with the top of the cylinder 4. The pipe 19 connects the cylinder 15 with the back of the cylinder 9, andthe pipe 20 connects the cylinder 16 with the front of the cylinder 9. In addition, -I show what I term a retard cylinder. 21 that isvplaced in comc-munication with the pipe 20 by meansofa pipe 22 (.see'Figure 1). 4 i c 1 Valves mounted inthe' cylinders 13 to 16 inclusive are.- controlled by pilot cylinders 23, 24, 25 and 26. Pipes 27 and 28 connect the pilot cylinders 23 and 24 to a remote control valve indicated generally at 29, this valve being shown in detail in Figure 2- 'A second remote control valve indicated generally at 30 is connected'by means of a pipe 31 tovthe pilot cylinders 25 and 26. 'Figure' 1 shows how the pipe 31 communicates with a passage 32 in the valve 12, and how thispassage divides into two branches,fthese branches communicating with the pilot cylinders 25 and 26. An enlarged sectional detail of valve 30'is shown in Figure 3. l I The va1ves'29 and 30 are connected bya pipe 33 to an air storage tank 34. .A pipe 7 35 taps the pipe 33-and conveys air to the cylinders13 to 16 inclusive when the valves in these cylinders are in certain positions;

valves in the cylinders 13 and 14 for controlling the piston rod 2, The cylinder 13 is provided with avalve seat36, (see Figure It is best nowto describe the action of the v 4), and a valve seat 37. Valves 38 and 39 are integrally connected to each other and intermittently seat, that is, when the valve 38 is seated the valve 39 is not, and vice versa. In like manner the valves40 and 41 are integrally connected to each other, and are mounted in the cylinder 14 and adapted to seat against valve seats 42 and 43 respectively.

valve guides by springs 48 and 49 respectively. These springs are weaker than the springs 44 and 45, so that normally the parts will remain in the position shown in Figure 4. The operating valve casing 12 has a passageway 50 therein for conducting air flowing from the pipe 35. This air passes through opening-s 51 and 52. The valves 38 and 40 have air-conveying grooves 53 and 54 therein for permitting air to flow from the passageway 50 into the cylinders 13 and 14. The pipes 17 and 18 communicate with the cylinder, and therefore the air will'flow through these pipes and be carried into the cylinder 4. Since the pressure of air in the pipes 17 and 18 is equal,

an equal force will bezexerted againstboth sides of the piston 3, and this will maintain the piston in a fixed position.

If the operator wishes to move the piston up and down, he merely exhausts air from above the piston or from beneathit, and permits additional air to enter the cylinder on the opposite side from that in which it is exhausting. This will cause a movement of the piston and in turn will move the dog 1. The remote control valve 29 is used for controlling the piston 3. This valvehas a handle 55 which, when swung to the right in Figure 2,

brings a passageway 56' into registration with the air supply pipe33 and the pipe 27.

It should be noted at this point that the valve 29 may be placed any distance from the operating'valve, and that this valve in turn can be placed any distance from the tong dogs 1 and 10 and their associate parts. It is convenient to mount the operating valve on the knee 7 a of the device.

A movement of the handle 55 to the right causes air to flow through the pipe 27 and into the pilot cylinder 23. i A sectional view shown in-Figure 5 illustrates the point at which the pipe 28 enters the pilot cylinder 24. The pipe 27 enters the cylinder 23 in a similar manner. The air forces the piston 46 upwardly, and this in turn seats the valve 38 and opens'the valve 39. Air ceases to flow from the passageway 50 into the pipe 17, but instead the pipe 17 empties'its air into the cylinder 13 and the air flows past the open valve 39 and into the pilot cylinder 23, through a passageway 57, across the top of a piston 58 in the retard cylinder 21 (this piston being in its lowermost position during this operation instead of in its uppermost position as illustrated) up through a bore 59 and out through exhaust ports 60. Figure 5 shows the cylinder 24 asbe'ing provided with an exhaust port 61. The cylinder 23 is provided with a similar exhaust port, this being shown at 62 in Figure 1. An adjustable plug 63 controls the flow of. air out through the port .61, and a similar plug 64 controls the flow of air out through the exhaust port 62. A portion ofthe air flowing from the pipe 17 throughthe cylinder 13 and on to the exhaustport 60, passes through the port 62. In this way two exhaust ports are provided, and the air will be permitted to quickly pass through the pipe-17 totdrain the air from the cylinder 4 directly beneath the piston 3 and to permit the piston to move downwardly quickly. V

The exhaust of air from beneath the piston 3 is caused by the flow of air through the pipe 18 to a'positionabove the piston 3. It should be remembered that during the time the valve 38 is seated and the valve 39 is unseated, the valves 40 and41 remain in the same position shown in Figure 4. Air will therefore flow through the openings 52,

grooves 54', cylinder 14, pipe 18,.and into the top of the cylinder 4.

I have described how a movement of the handle 55 to the right will cause the dog 1 to move downwardly with a force suflicient to drive the dog point 65 into a log. The dog lean be reversed in its movement, that is, be

moved upwardly, this being accomplished by a mere swinging of the handle 55 to the i left from the neutral position shown in Figure 2. Thiswill direct air through the pipe 28 into the pilot cylinder 24, which will seat the valve 40 and open the valve 41. The

rocking of the handle 55 to the left places the pipe 27 in communication with an exhaust port ,66, andthis permits the air to dram from the pilot cylinder 23 and to allow the valve 39 to seat and the valve 38 to open.

The flow of air through the cylinders 13 and 14 will now be reversed. The cylinder 14 Wlll exhaust am from the top of the cylinder 4, th1s air passing through grooves 67 into the pilot cylinder 24, and thence out through the exhaust port 61; Air will enter the pipe 17 and will-fill the lower part of the cylinder 4' to raise the piston 3.

The piston can'be stopped in any position desired by merely swinging the handle 55 back into neutral position as shown in Figure '2. This places both pipes 27 and 28 in communication with the exhaust 66, permits valves 39 and 41 to seat, and causes an equal pressureof air to enter pipes 17 and 18.

When the tong dogs 1 and 10 receive a cant11ainstea-d of a-log- 11,the' stanchion 6 is moved back (see Figure 6). Thisis accomplished by moving the piston 8 within thecylinder 9, and this movement-in turn iscontrolled by the valves in the cylinders and 16, see Figure 4 and the remote control valve 30, seejFigure 3. The oylinder15 has a valve 67 mounted therein which is adapted to seat against a valve seat'68. A piston 69, mounted in the pilot cylinder 25, bears against the shank of the valve 67 and is held against theshank by a spring 70. Valves 71 and 72 are connected to each other and are mounted int-he cylinder 16. Valve seats 73 and 7a are provided for the valves 7 land 72 respectively. A piston 7 5 bears against the shank of thevalve 72 and is yieldingly held in position by means'of' a spring 7 6.

It will he noted from the constructions of the valves 67, 71 and 72 that air inthe passageway 50 will keep the valves 68 and 72' seated and the valve 71 open. Air will nor- "mally flow past the valve 71 and through the pipe to move the piston 8 toward the right in Figure 1. This will exhaust the air from the right hand end of'the cylinder 9, and

this air will'be forced through the pipe 19 61 shown in Figure 5.

into the cylinder, 15, through a groove 77 in the valve shank 67, thence intofthe cylinder 25, and out through the exhaust port 78 (see Figural) this port being similar to the port The piston 8 will therefore be at the extreme right end of its stroke when looking at Figure 5 'when a handle 79 of the valve is in vertical position as shown 11'] Figure 3.

If now the handle 79 is swung to the left, it will place the pipe 33 in communication with the pipe 31, and this will raise both the pilot pistons 69 and 75, opening the valves- 7 2 and closing the valve 71. The pas- 68 ano. sage of a r to the cylinder 9'willnow bereversed. air flowing through the pipe 19 into the cylinder and through the pipe 20 away from the'cylinder. This causes the piston 8- to move to the extreme left hand position and to carry the stanchion 6v therewith.

It should be noted at. this point that when the piston -8 is at the extreme right of its stroke (see Figure 6.), the stanehionf6 ispulled back for positioning the dogs for receiving thecant 11a. It is necessary to'cut down the force exerted upon thehammer dog 1 and to out down the speedof the dog as it 1. is lowered into engagement with the cant in order to prevent the dog from biting a sliver out of the cant. I accomplish thisretarding movement of the dog 1 automatically in the following manner. When the valves 68, 71

and 72 are in the positions shown in Figure 4, the piston 8'will be at its extreme right hand position as shown in Figure 6. -A portion of the air. flowing through the pipe 20 into the left hand end of the cylinder 951's 3 directed through the pipe 22 (see Figure 1) v into the retard cylinder 21. The cylinder 21 ls shown in Figure 4. The air flowing from the pipe'22 raises the piston 58Iinto the {position shown in Figure 4. This cuts oil any escape- 0f air from the pilot cylinder 23 through the exhaust openings .60. Air flows throughthe cylinder 23 only-when the dog 1 Y is being moved downwardly; j All of the'air flowing from beneath the piston 3 in the cylinder' will therefore have to flow through the exhaust port 62. The passage of air through this-port is slowed downtothe de- I sired 'extentso as to cause the .dog'l to be 'loweredslowly. The-dog willftherefore engage'with the cant gently so as to: nottear a piece therefrom. A shorterdog point 65a engages with the "cant instead of the'point 65. 'Of course, the air will continue to leak through the port 62 after the dog-1' has engagement with the cant.

From the foregoing description of the'various parts of the device, the operation thereof will be readilyunderstood. 1

When the saw mill receives a new log, the operator throws the handle-79m the right (see Figure 3), this causing the pistons 69 and 7 5 to move the valves. 68, 71 and 72 and to admit air to the back of the'cylinder 9 andto permit it to exhaust from the front of v the cylinder. This moves the stanchion forwardly. The operator can now actuate the handle 55 to the left (see Figure 2) which 7 causes the piston 47' to close the valve and to open the valve 41, thus permitting air to enter the bottom of the cylinder 4 through the pipe17 and to escape from the top of the cylinder. This raises the dog 1. The upward movement of the dog can bestopped'at any point by the operator throwing the handle '55 into neutral position,xwhich causes the valves 38, 39, 40 and 41 to assume the positions shown in Figure 4 and to admit air to the top and. bottom ofthe cylinder 4, thus creating a perfect balance upon the piston 3. V

W'hen the'log is received, the dog 1 can be brought down into engagement with the log.

This is accomplished by throwing the'handleto the right (seeFigure 2). This closes l r the valve 38 and opens the valve39 and-permits air toexhaust from beneath the piston 3and flow out through the pipe 17. Air is being fed into the top ofthe cylinder 4,

and has sufiicient force to swing the dog 1 A into engagement with the log. 'During'this movement the air flowing through the pipe 17 exhausts through the port 62 and the port 60.

s Now when the log has been sawed on three 7 last plank.

sides and-is turned the last time, the dogs 1 and 10 have to be drawn back to within about one inch from theface of the knee 7a to allow the cant 11a to be sawed up to the It is obvious that if the upper dog arm descended with thecsame velocity that is re quired to hold a round log, it would likely biteofi along sliver out'of thecorner of the cant. The purpose of the retarding cylinder 21 is to cut down the speed of the movement of the dog ,1. c As heretofore stated, the piston58 in the retardcylinder 21 is raised when the handle 7 9 of the valve 30 shown in Figure 3 is swung; into vertical position. This permits air to exhaust from beneath the piston through the small 'port 62 instead of through this port and the port 60. The retard cylinder cuts ofithe port 60. The slow exhaust of airfrom beneath the piston 3 causes the dog 1 to move downwardly slowly.

It will be noted from Figure 6 that the doglis connected by a link 100 to a pivot point 101 and that the dog 10-isconnected to the same pivot point by-a link 1052. When the. dogs 1 and 10 are moved into retracted position by the stanchion 6, the links 100 and 102 are swung beyond a vertical line passing through the. pivot point 101. Air pressure in the upper-part of the cylinder l, tending to bring the dogs 1 andlO toward each other, will-also tend to swing the link 100 in a clockwise direction and the link 102 in acounterclockwise direction, because, as

already stated, these links have been moved beyond dead center. This tendency to swing the links will cause them to tend to move cylinder, selective means for causing any one of said pistons to move its respective valve, an exhaust port communicating wlth ease of said first namedcylinders, an auxiliary exhaust port communicating with one of said cylinders, andautomati'c pneumatically-controlled means for connecting the auxiliary exhaust port to and for disconnecting'it from its communicating cylinder.

2. An operating valve comprising a plurality of cylinders having intake and exhaust ports, valves for controlling the flow of air through said ports, a retard cylinder having an exhaust port normally in communication with one of said first named cylindcrs, a plurality of pilot cylinders, pistons mounted therein, means for directing air intosaid pilot cylinders for causing saidpistonstoactuate said valves, a piston mounted insaid retard cylinder, and means for directing air into said retard cylinder for causing the piston therein to close the exhaust port in said cylinder. I

3. An operating valve comprising a plurality of cylinders, valves mounted in said cylinders, a pilot cylinder for each of said first named cylinders, a piston for each pilot cylinder, selective means for causing any one of said pistons to move its respective'valve, an exhaust port communicatingwith each of said first named cylinders, and an auxiliary exhaust port communicating with one of said cylinders. I

4:. An operating valve comprising a plurality of cylinders, valves mounted in said cylinders, a pilot cylinder for each of said first named cylinders, a piston for each pilot cylinder, selective means for causing any one of said pistons to move its respective valve,

an exhaust port communicating with each of said: first named cylinders, an auxiliary exhaust port communicating with one of said cylinders, adjustable means for controlling the size of the auxiliary exhaust port, and automatic. pneumatically-controlled means for connecting the auxiliaryexhaust port to and for disconnecting it from its communi-.

eating cylinder.

5. An operating valve comprising a plurality of cylinders, valves mounted in said cylinders, a pilot cylinder for each of said first named cylinders, a piston for each pilot cylinder, selective means'for causing any one o1 said pistons to move its respective valve,

'an exhaustport communicating with each of said first named cylinders, and an auxiliary exhaust port communicatlng with one of said cyllnders, and means for connecting the auxiliary exhaust port to and for dis.

connecting it from its communicating cylinder. V

c 6. In a valve construction, a cylinder havinga valve seat at each end, valves reciprocably mounted in said cylinder and being connected-to each other for alternately closing the valve seats, means for delivering air into the cylinder .Ithrough one of the valve seats, a' pipefor conveying air to and from the cylinder, a pilot cylinder communicating'with the first named cylinder through the othervalve, a piston mounted in said pilot cylinder for moving said valves, pneumatic means for moving said" piston, said pilot cylinder having an exhaust port, an auxiliary exhaust port for saidpilot cylinder, and a pneumatically controlled piston for connecting the auxiliary exhaust port to and for disconnecting it from the cylinder. 7 i

' ERVIE A. FERRIS.

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