US2576520A - Hydraulic control of veneer slicing machines - Google Patents

Description

Nov. 27, 1951 1.. F. KOSS 2,576,520

HYDRAULIC CONTROL. OF VENEER SLICING MACHINES Filed Nov. 4, 1948 5 Sheets-Sheet l mam; EIDQD 919cm; qua-9 2mm; Qua]; QBGD 911m; um; 2mm;

Iwvsrrron, Lou's F Koss, :zarwmm flTTORNEY.

Nov. 27, 1951 L. F. Koss 2,576,520

HYDRAULIC CONTROL OF VENEER SLICING MACHINES Filed Nov. 4, 1948 5 Sheets-Sheet 2 INVEN TOR,

LOUIS F Kass,

flTTORNEY.

Nov. 27, 195] L. F. KOSS HYDRAULIC CCNTROL OF VENEER sucmc MACHINES 5 Sheets-Sheet 3 Filed Nov. 4, 1948 INvEN-roR, Lows F Kos E f/Maj Nov. 27, 1951 1.. F. KOSS 2,576,520

HYDRAULIC CONTROL OF VENEER SLICING MACHINES Filed Nov. 4, 1948 5 Sheets-Sheet 4 Nov. 27, 1951 L. F. Koss HYDRAULIC CONTROL OF VENEER SLICING MACHINES 5 Sheets-Sheet 5 Filed Nov. 4, 1948 Y. E M R 3 0 OS T T T m Q vcl s O L E Patented Nov. 27, 1951 UNITED STATES PATENT OFFICE HYDRAULIC CONTROL OF VENEER SLICING IVIACHINES Louis F. Koss, Indianapolis, Ind., assignor to q Capital Machine Company, Indianapolis, Ind., a corporation of Indiana Application November 4, 1948, Serial No. 58,323

4 Claims.

' This invention relates to a veneer slicing machine and particularly to that type of machine as illustrated in applicants prior Patents Nos. 2,184,862 and 2,303,213, wherein the log or fiitch is clamped on a diagonally upright reciprocating table between upper and lower dogs, and a slicing knife carried by an extremely heavy bed is progressively moved horizontally toward the log for successive slicing operations.

The invention herein shown and described relates primarily to controls of the operation of the machine, and primarily to the hydraulic control. By reason of the use of the present invention, the machine may be operated at speeds far above those previously employed, namely above fifty strokes per minute.

The present invention in addition to initial hydraulic dogging operations to secure the fiitch on the table, includes the automatic control of the moving parts wherein the table is almost instantaneously stopped upon a condition where the log might slip slightly to extend further from the table than it should for a successive cut in such a condition where the knife might jam under the log; a condition which prohibits the inching up along the table of the dogs once they are set on the log; and for the condition where the log might fall 011 the dogs or a pipe fitting or hose in the hydraulic system break. In the two conditions where the knife may jam under the log, or there be a break in the hydraulic system, or the log itself fall off from between the dogs, the invention provides for a control whereby the driving motor reciprocating the log up and down the table guides is immediately cut off from the electrical power and at the same time a brake is applied to stop the entire mechanism.

These and many other objects and advantages of the invention including the extreme ease provided for handling the various operations, the high degree of safety to prevent breakage of the machinery in case of any one of the foregoing conditions occurring, all permitting the speeds of operation far above those previously employed, will become apparent to those versed in the art, in the following description of one particular form of the invention as illustrated in the accompanying drawings, in which Fig. 1 is a view in front elevation of a machine embodying the invention but with the knife cutter bed removed;

Fig. 2, a view in rear elevation;

Fig. 3, a view in right-hand end elevation;

Fig. 4, a diagrammatic representation of the means for applying the brake;

Fig. 5A, a view diagrammatically illustrating the left-hand portion as viewed from the rear of the machine of the hydraulic control system;

Fig. 5B, a diagrammatic representataion of the right-hand end portion of the hydraulic control system as viewed from the rear of the machine;

Fig. 6, a view on an enlarged scale through a' check valve;

Fig. 7, a view in vertical central section through a control valve;

Fig. 8, a view in horizontal central section through the same valve; and

Fig. 9, a wiring diagram of the electrical control.

Referring to the drawings in which like characters of reference indicate like parts through-- out the several views, a bed supports a driving motor 5| which through a system of gearing 52 reciprocates the fiitch table 53 along the inclined guides 54, 55, and 56. On the bearings 51 and 58 is supported the bed plate 59 which carries the usual cutting knife. The knife carrier 59 is advanced and retracted from the face of the table 53 in the usual manner through the lead screw shaft 60. Then on the front face of the table 53 there are mounted a plurality (eleven in the present showing) of sets of dogs, a lower dog GI and an upper dog 62 in each set, both vertically reciprocable between the spaced guides 63, 64, and 65.

' All of the construction so far described is shown in the two prior U. S. patents to which reference has above been made.

A primary control valve I0 is employed which will serve to control seven of the pairs of'dogs GI, 62, as will be presently described.

A pump 8, Fig. 5A, is employed to produce a relatively high pressure on the order of eighthundred pounds per square inch and above, but

with a relatively low volume flow. This pump 8 takes oil from a tank 23 through an intake pipe 1 and delivers it through a pressure regulator valve 9 into the supply pipe H which discharges to the valve N]. This valve I0 is provided with a pair of pistons 2 and 3 spaced apart along an operating piston rod l which is externally connected to an operating lever la. These two pistons 2 and 3 may be slidingly reciprocated within a cylinder 4 which is axially mounted within the valve body Illa to extend across a number of chambers provided in that body. This cylinder 4 opens at its ends respectively into the chambers 22!) and 220 which are interconnected the passageway 22a opening out into a discharge or exhaust pipe 22, this pipe 22 being carried back to discharge into the tank 23. The pressure supply pipe |I discharges into a central body chamber I Ia, and the cylinder 4 is provided with ports 4a to provide communication from that chamber No to inside of the cylinder 4%. In like manner, this cylinder 4 is provided with ports 41: opening into the chamber 2 Ia and ports 40 opening into the chamber I2a. These chambers |2a and 2 la respectively are interconnected with the pipes I2 and 2 I.

Assuming that the table 53 is stationary, an that it is desired to place a log upon the table between the various sets of dogs 6| and 52, the initial operation is to spread apart those dogs 5| and 62 in each of the eleven sets illustrated.

To do this, the valve I is manipulated to have the pistons 2 and 3 in those positions as illustrated in Figs. 7 and 8. The pump 8 is set into operation to supply oil under pressure to the valve I 0 as previously described. The oil entering the chamber Ila flows into the inside of the cylinder 4 through the ports 4a and discharges from that cylinder between the pistons 2 and 3 through the ports 40, to have that oil flow out through the pipe I2. Referring to the diagram, Fig. 5A and 5B, thispipe I2 is intercom nected to a manifold pipe I3 horizontally disposed along the rear sides of pairs of vertically disposed cylinders I6, IT with the interspersed pairs of like cylinders 28, 29 between the pairs of cylinders IE, II. In this regard, there is shown to the left end, Fig; 5-A,; ,a pair of cylinders I6, [1; next a pair of cylinders 28, 29, and a second set of cylinders I6, |I; next a third set of cylinders I6, II; followed by a second occurring pair of cylinders 28, 29 (Fig. 53); next a single pair of cylinders IE, IT; a single pair of cylinders 28, 29; two pairs of cylinders I6, II; then a pair of cylinders 28, 29; and finally on the end a pair of cylinders I6, II. In other words, there are seven pairs of the cylinders I6, I! and four pairs of the cylinders 28, 29. The seven pairs of cylinders are employed to be the primary means for dog-- ging the log, and the four pairs of cylinders 28, 29 are auxiliary cylinders to follow up in the dogging operation to provide further securing means along the log in spaced relation, the secondary four pairs operating in the same manneras the primary pairs of cylinders I6, I! as will be further explained.

In each of the cylinders I6 there is provided a piston 19 which is connected to the connecting rod II in turn extending downwardlyfrom the cylinder to the dog 5|, this being the dog which is to be pulled up against the underside of the log, and consequently the-cylinder I5 is in the present showing provided to have a larger diameter than that of the. cylinder II. Then the cylinder I! is provided with a piston I2 therein connected to the connecting rod I3 which extends downwardly to engage with thedog 82, this being the dog which is pushed down on top of the log whereby the log is interengaged between :thosesets of dogs GI, 62; Thecylinders 28 and 29 are exact duplicates of the cylinders IG and II re-- spectively and therefore have the same pistons III and I2 carried therein interconnecting with the lower extending rods II and I3 to their respective dogs SI and B2. 7

From the manifoldpipe i3 there is provided a pip I4 interconnecting the pipe I3 with-the upper ends respectively of the cylinders I6 in each instance. Likewise from the pipe 13 there the horizontally disposed manifold pipe 21. This opposite respective ends of these cylinders 28, 29

through the pipe I2, that oil will flow into the upper and lower ends respectively of cylinders I6 and II, and thereby drive the pistons I0 and I2 to their respective lower and upper ends whereby the dog 6! and 62 are spaced apart one from the other their major vertical distance permissible.

Since the hydraulic system is a closed system, there will have been oil on the opposite sides of those pistons I0 and I2, and this oil escapes respectively from the lower end of the cylinder It and the upper end of the cylinder |I through the pipes I3 and I9 respectively interconnected with the horizontally disposed manifold pipe 20. The pipe 2| is interconnected between the pipe 26, herein shown as at the left-hand end, Fig. 5A, and the valve II! to communicate with that chamber 2Ia therein. Thus oil flowing toward the valve I9 can flow through the ports 4b into the cylinder 5 and out the end of that cylinder into the chamber 220, and flow through the interconnecting passageway 22a to discharge through the pipe line 22 back into the supply tank 23. Attention is directed to the fact however that interposed in this pipe 2| there is a check valve 29a which is illustrated in detail in Fig. 6.. Normally the flow just described of the oil through the pipe 2| would be prevented by reasonof the fact that the poppet valve .IA is seated and nor.- mally, remains seated by means of an extremely light coiled spring I5 operating between the underside of the ,valve body and a piston I6. O-il pressure in the upper end of the cylinder |6 will be communicated through a tube 11 leading from that end ofv the cylinder It to the underside of the piston It so that the pressure in the cylinder IE will tend to lift the poppet valve I4. By reason of the fact-that the pipe 2| which would then be the outlet of the relief or check valve 280. is interconnected through the valve I0 tothe atmospheric pressureat the tank 23, this.

piston I6 may lift the valve! to permit. the flow of oil from the opposite end'of the cylinder I6 out through the pipe 2|. In other words this opening from the one cylinder. I6 will serve to open the valve III which is otherwise normally seated.

A second valve 25 is employed to control the sets of cylinders 28, 29 in exactly the same manner. the pipe II through the pipe 31 across through pipe 21 is interconnected respectively between the top end of the cylinder 28 and the lower end of the cylinder 29 by the pipes 3 0 and 3|. The

are interconnectedthrough the pipes 33 and 34 with the horizontally disposed manifold pipe 32.

From the pipe 32 there is the return pipe 35 leading back down to the valve 25 to permit flow of oil into that valve and across out through the discharge pipe 36 to the exhaust pipe 22 and finally to the tank 23.

Thu with both valves II] and 25 operated as described, all of the dogs inall of the pairs will be fully spread apart so that the log or flitch (not shown) may be placed up against the-table.

in the desired position, preferably diagonally thereacross, and held while the handle of the valve I9 is shifted for further operation of these dogs BI, 92. I

To accomplish the dogging the dogs 6|;"62with the log, the pistons 2 and 3 is a pipe I5 connecting with the lower ends of' I the cylinders I'I. Therefore whenoil is applied are shifted tov have :the piston 210M118 to the opposite end of the -cylinder 4,fromthat'shown In this case, oil under pressure flows from action to engage in'Figs. 7 and 8. Of course the piston 3 being fixed to the rod is carried therealong and positioned accordingly.

With the valve then conditioned as indicated, oil under pressure enters the chamber Ila from the pipe I and flows out through the ports- 4a into the cylinder 4 and then out through the ports 41) into the chamber 2 la. From the chamber 2 la there leads a pipe 2| which is carried back to the check valve 20a, this bein the same pipe as previously described and interconnecting with that valve. In other Words oil is now flowing under pressure through that pipe, and across through the valve 20a, lifting the poppet valve 14, and entering into the manifold pipe 20. Thus the pipe 20 is now under pressure, this pressure being built up to the order of around eight hundred pounds per square inch or even above. "The pressure in the pipe 20 is communicated to the lower and upper ends respectively of the cylinders I6 and I1, thereby driving up the piston I and driving down the piston 12 to cause the clamps 6| and 62 to interengage-the log on the table therebetween. When the dogs are firmly set against the log, and there is no additional flow of oil from the pipe 2| into the pipe 20, the poppet valve 14 becomes seated, or at least it becomes seated against any tendency of return flow of oil back from the pipe 20 through the valve 20a. As will be noted in the diagram, Figs. A and 53, there are additional check valves 38, 39 and 40 interspersed along the manifold 20 to serve the same purpose as does the valve 20a. These valves are provided in addition to valve 20a for the reason that the manifold pipe 29 is of relatively long length, and it is desired that the pressure be maintained constant in that line 20 after the dogs 6| and 62 have engaged the log therebetween. The slight minor shifting of the set of dogs at any one position would thus not change the pressure materially in the line 20 in respect to the pressure applied at other pairs of dogs BI and 62.

When the pressure has been applied to the manifold 20, and the pistons and 12 start going up and down respectively in the cylinders l6 and I1, oil of course must be removed from the opposite ends of those cylinders I6 and I! to permit that travel. In this case, the oil is discharged from the top end of the cylinder Hi to the pipe 5 l4 and from the bottom end of he cylinder I! to the pipel5 so that the return flow is to the common manifold Hi. Pressure escapes from this pipe l3 to the pipe l2 by flow of oil therethrough back to the valve l0 and across the chamber |2a through the ports 40 then uncovered by the piston 3 and out the end of the cylinder 4 into the chamber 221) and thence around through the chamber 22a and out the exhaust line 22 back to the tank 23. I

There is provided a major relief valve 4| placed in a line 80 which is interconnected with the pipe at various intervals between the different check valves 20a, 38, 39, and 40. Pressure is thus transmitted from the manifold pipe 20 to the relief valve 4|. This valve is normally set to remain closed up to pressures eight hundred pounds per square inch or thereabove as may be selected. The relief flow from that valve 4| is had through a pipe 8| back to the manifold 3 so that the oil in excess pressure may flow back through the pipe I2 and through the valve l0 to the tank 23 as just described. There is the possibility at times of a log or flitch tending to slip from between the dogs, but still not drop'entirely out from therebetween. In this condition, the log would extend itself into the path of the knife to such a degree that it would tend to become jammed over the knife. In this regard, there is a force of some twenty-five thousand pounds to be stopped before damage is done to the knife or to the carriage and its operating mechanism. When this condition occurs, and the log comes down on top of the knife, there of course is a resistance built up to further the travel of the carriage, and this is reflected through the dog 62 primarily to tend to increase the pressure in the manifold line 20. To take care of this situation and stop the machine at once, there is provided a pipe line 4| leading from the pipe 20 fromthe normally closed side of the check valve 2011. This line 4| leads back to a high pressure controlling switch 42. The switch in this mechanism is in a circuit so designed as to open the circuit leading to the driving motor 5|, see Fig. 9. The building up of the pressure which would be communicated through this line 4| acts almost instantaneously to trip the switch in the unit 42. Incidentally this unit 42 is of the usual and well known construction where a switch is to be operated by differences in pressure, and hence the details of th mechanism are not herein shown.

Simultaneously with the operation of the high pressure controlled switch unit 42, the-winding of a solenoid 83, Fig. 4, is deenergized to lift the latch 84 out of the notch'85 in a horizontally disposed rod 86 carried in the present form inside of a cylinder 81 to have an end portion 88 carry a roller 89 in the path of the usual brake lever 90.- When the latch 84 is lifted, the bar 86 may travel toward the lever 90 by reason of the pressure exerted by the spring 9| carried against an abutment 92 fixed on the rod 86 and bearing against a stop 93 placed within the tube 81.

This brake lever 93 is normally hand operated,- but in the emergency just described, the bar 86 through the pressure of the spring. 9| operates the lever 9|! to a brake applied position.

As indicated in Figs. 3 and 4, the brake 9G is fixed to a shaft 94 which carries a lever 95 in turn rockably connected to a brake rod 96. The brake rod 96 is rockably connected to a lever 9'! pivoted on the pin 98 to a fixed member such as' a portion of the base 50. The lever 9li-has the other end secured to a brake band'99 which wraps around a brake drum" Isl! that is carried in fixed position adjacent the drive gear 52a of the gear system 52. The other end of this brake band 99 is carried back into a fixed connection with the face 50, herein shown as being secured under the bracket ill on which the lever 91 is pivoted. By reason of the relatively large diameter of the brake drum I00, the band 99 requires but slight-pull by the lever 91 to apply the braking action sufiicient to bring the entire mechanism to a very quick stop. This brake of course is applied simultaneously with the disconnecting of the motor 5| from the power circuit by the action of the high pressure switch unit 42. Thus through the slight degree of upward travel permitted by the upper dogs 62, to build up the increased pressure to apply a surge in effect to the high pressure switch unit 42, the table 53 is almost instantaneously stopped in its downward travel, and at least before any damage is done. The motor 5| has to be manually started before the table is again reciprocated, and this of course permitsv correcting the difficulty. There is also'the possibility of a log becoming entirely disengaged from the dogs :6|,

and 62, or a pipe fitting or a' pipe line or a hose connection breaking. In this case,' there is a difierent type of surge set up in the hydraulic system. With the quick reduction in pressure which would be occasioned by the dogs 6! and 62 relatively travelling one toward the other, or with a pipe line break, more flow of oil would be tended to be set up through the pipe line 2|, but since the pump 8 is limited in its volume of flow, the. pressure in the line H is instantly reduced. In this case, the low pressure operated switch unit I05 is operatedrto break the circuit between the power source and the driving motor 5|, and the solenoid is again operated to permit the bar 86 to apply the braking action through the band 99 as above described, thereby again bringing the entire mechanism to a quick stop.

Therefore it is to be seen that there is provided a relatively simple hydraulic control of the slicing machine to such an extent at least, that the table 53 may be reciprocated at a speed far above that heretofore possible because the controls are such that the machine may be stopped before it is damaged beyond repair.

It is to be borne in mind, that as above indicated, there are enormous forces to be controlled in a machine of this type. As above indicated, the log plus the table and other associated elements will weigh around the neighborhood of twenty-five thousand pounds, and this is no little mass to be stopped almost instantaneously. This however is made possible by reason of the unique hydraulic control system abovedescribed. Moreover where these machines go out into remote places far removed from sources of transportation and supply of parts, it is highly important that the machine be kept in operating condition because it requires an exceedingly long time to get repair parts and replacement parts to the user. 7

Therefore While I have herein described and illustrated my invention; in the one particular form, it is obvious that various changes may be made such as in the specific piping arrangement, all without departing from the spirit of the in vention, and I therefore do not desire to be limited to that precise form beyond the limitations which may be imposed by the following claims.

I claim: V r

1. In a veneer slicing machine having a vertically reciprocating flitch table driven by a motor, a plurality of pairs of opposing dogs independently shiftable over the table, hydraulic cylinders one for each dog, a piston in each'of said cylinders interconnected with one of said dogs whereby fluid underpressure may be applied to either side of said piston to effect selective travel of the dogs, a system responsive to movement of said dogs for controlling said 'machine automatically comprising a high pressure,

surge in pressure above said normal and said first 'Inanifold operating to stop said motor; and

means responsive to a surge in downward pressure insaid first manifold operating to stop said motor.

2. In a veneer slicing machine having a vertically reciprocating flitch table driven by a motor, a plurality of pairs of opposing dogs independently shiftable over the table, hydraulic cylinders one for each dog, a piston in each of said cylinders interconnected with one of said dogs whereby fluid under pressure may be applied to either side of saidrpistons to effect selec tive travel of the d0gs,-a system responsive to movement of said dogs forcontrolling said machine automatically comprising a high pressure. low volume, output fluid pump; a'normally pump pressurized manifold interconnected with the tops and bottoms of said cylinders and said pump to receive fluid from said pump for shifting said opposing dogs, one toward the other for flitch gripping action therebetween; a second manifold normally under lower pressure than said first manifold and interconnected with the bottoms and tops respectively of the cylinders in reverse order of connections with said first manifold; means arresting back flow from said first manifold to said pump to maintain a normal flitch holding pressure; means responsive to -a surge in pressure above said normal and said first manifold operating to stop said motor; and means responsive to a surge in downward pressure insaid first manifold operating to stop said motor; valve. means for reversing pump induced fluid pressure from said first manifold to said second manifold to reverse travel of said dogs, one from the other in each of said pairs to have said cylinders exhaust into said first manifold; and means operative by pressure in said second manifold for rendering inoperative said backflow arresting means. i

3. In a veneer slicing machine having a vertically reciprocating flitch table driven by a motor, a plurality of pairs of-opposing dogs independently shiftable over the table, hydraulic cylinders one for each dog, a piston in each of said cylinders interconnected with one of said dogs whereby fluid under pressure may be applied to either side of said pistons to effect selective travel of the dogs, a system responsive to movement of said dogs for controlling said machine automatically comprising a high pressure, low volume; output fluid pump; a normally pump pressurized manifold interconnected with the tops and bottoms of said cylinders and said pump to receive fluid from said pumpfor shifting said opposing dogs, one toward the other for flitch gripping action therebetween; a second manifold normally under lower pressure than said first manifold and interconnected with the bottoms and tops respectively of the cylinders in reverse order to connections with said first manifold; means arresting back flow from said first manifold to said pump to maintain a normal fiitch holding pressure; means responsive to a surge in pressure above said normal and said first manifold operating ,to stop said motor; and means responsive to a surge in downward pressure in saidfirst manifold operating'to stop said motor; and means" reducing said surge pressure to at least said normal pressure.

4. In a veneer slicing machine having a vertically reciprocating fi'itch tabledriven by a motor, a plurality of pairs of opposing dogs independently shiftable over the table,'hydrau1ic cylinders one for each dog, a piston in each of said cylinders interconnected with one of said dogs whereby fluid under pressure may be applied to either side of said pistons to efiect selective travel of the dogs, a system responsive to movement of said dogs for controlling said machine automatically comprising a high pressure, low volume, output fiuid pump; a normally pump pressurized manifold interconnected with the tops and bottoms of said cylinders and said pump to receive fluid from said pump for shifting said opposing dogs, one toward the other for fiitch gripping action therebetween; a second manifold normally under lower pressure than said first manifold and interconnected with the bottoms and tops respectively of the cylinders in reverse order of connections with said first manifold; means arresting back flow from said first manifold to said pump to maintain a normal flitch holding pressure; means responsive to a surge in pressure above said normal and said first manifold operating to stop said motor; and means responsive to a surge in downward pressure in said first manifold operating to stop said motor; said high surge pressure responsive 10 means comprising a predetermined pressure opening switch in circuit with said motor and a motor brake control mechanism; said low surge pressure responsive means comprising a second predetermined pressure opening switch in circuit with said motor and said motor brake control system.

LOUIS F. KOSS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 720,719 Malmstrom Feb. 17, 1903 1,744,228 Kaufmann Jan. 21, 1930 2,184,862 Koss Dec. 26, 1939 2,236,467 Clench Mar. 25, 1941 2,303,213 Koss Nov. 24, 1942 2,362,339 Armington Nov. 7, 1944 2,384,962 Pohl Sept. 18, 1945

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