US3815763A - Grinder feeding system - Google Patents

Abstract

A system for feeding a grinder having at least one pocket for receiving logs to be grounded. The system comprises a magazine located above the grinder pocket for storing logs to be fed into the grinder pocket, a conveyor system located above the grinder for feeding logs to the grinder, and a gate located in the conveyor system right above the magazine for discharging logs into the magazine. The magazine includes a plurality of loading boxes located one above the other and each including a gate for permitting one box to discharge into the box below.

Description

United States Patent 1 Biloco et al.

1 GRINDER FEEDING SYSTEM [73] Assignee: Forano Limitee, Plessisville,

Quebec, Canada 22 Filed: Feb.24, 1972 21 App1.No.:228,952

[52] U.S. C1 214/16 R, 198/66, 198/83, 241/34, 241/281, 241/282 [51] Int. Cl. B65g 47/44, B65g 65/32 [58] Field ofSearch 214/16 R, 16 B, 17 C; 241/34, 281, 282; 222/56, 436; 198/110, 82, 65, 66, 69

[56] References Cited UNITED STATES PATENTS 909,188 1/1909 James 222/436 2,053,505 9/1936 Waterous 241/282 2,588,448 3/1952 Worm et a1 241/282 3,198,386 8/1965 Hartley 222/56 X 3,310,080 3/1967 Delcellier, 198/66 X 3,342,351 9/1967 Sinjavosky et a1. 214/16 R 1 June 11, 1974 Primary -Examiner-Evon C. Blunk Assistant Examiner.lames W. Miller Attorney, Agent, or FirmBacon & Thomas [5 7] ABSTRACT A system for feeding a grinder having at least one pocket for receiving logs to be grounded. The system comprises a magazine located above the grinder pocket for storing logs to be fed into the grinder pocket, a conveyor system located above the grinder for feeding logs to the grinder, and a gate located in the conveyor system right above the magazine for discharging logs into the magazine. The magazine includes a plurality of loading boxes located one above the other and each including a gate for permitting one box todischarge into the box below.

' 3 Claims, 4 Drawing Figures PATENTEBJuu 1 1 1974 SHEEY 2 BF 3 PATENTEUJUM 1 am SHEEY 3 OF 3 PL-&

FIG. 4

GRINDER FEEDING SYSTEM This invention relates to a grinder feeding system.

The feeding of grinders has always been a problem and many attempts have been made to provide an automatic grinder feeding system. However, the known systems are complicated and, consequently, have continu ous mechanical and electrical failures resulting in high cost of maintenance. In one known feeding system, the conveyors are located betweenthe grinders and are arranged to open themselves and let the logs fall into magazines located underneath the conveyors. The magazines are movable and may be shifted over to one side or the other to load the grinder pockets. Such a system is not satisfactory because it requires the presence of an operator at all times for moving the magazines over to the empty grinder pockets.

It is the object of the present invention to provide an automatic grinder feeding system which requires less attendance than the known feeding systems and is also very simple in operation.

The grinder feeding system, in accordance with the invention, comprises a series of boxes located above the grinder pocket for storing logs to be fed into the grinder pocket, a conveyor system located above the boxes for feeding logs to the grinder, and a gate located in the conveyor system right above the boxes for discharging logs into the grinder.

The magazine includes a plurality of loading boxes located one above the other and each having a gate for permitting one box to discharge into the box below. This increases the reserve of wood to be fed into the grinder pocket and thus permits a single operator to look after plural grinders.

A metering box is located right underneath the gate in the conveyor system for measuring the amount of wood to be discharged into the upper loading box and means are provided for successively operating the metering box gates and the gates of the loading boxes for feeding the logs to the grinder pocket. As soon as the metering boxes are empty, the gate in the conveyor system may be opened to discharge logs into the metering boxes. However, if the attendant is busy looking after another grinder, there will be a sufficient reserve of logs in the loading boxes to permit him to look after such grinder before having to come back to fill the metering gates by opening the gate in the conveyor system.

The conveyor system is adapted to feed plural grinders in series and flat belt conveyors are provided on each side of the gates above the grinder magazines f feeding the logs.

The grinder used in the present invention comprises two grinder pockets one on each side therof and two separate magazines for feeding the grinder pockets. Consequently, a short conveyor is needed between the gates in the conveyor system. Such short conveyor may be of the chain multiple strand type or belt.

The conveyors are independently reversible so as to permit them to more easily feed logs into the conveyors and also to permit piling of a plurality of layers of wood on the conveyors.

The invention will now be disclosed with reference to a preferred embodiment thereon and to the accompanying drawings in which:

FIGS. 1 and 2 illustrate side and top views respectively of the grinder feeding system in accordance with the invention;

FIG. 3 illustrates a side view of the grinder magazines associated with a grinder; and

FIG. 4 illustrates a control system for operating the conveyors, the metering box gates, and also the gates associated with the loading boxes of the magazines.

Referring to FIGS. 1 to 3, there is shown a conveyor system including a plurality of flat belt conveyors E0 of the conventional type which are arranged to feed logs to a series of grinders 12 located below the conveyors. The flat belt conveyors each include a belt 14 supported by end rollers 16 at least one of which is a driving roller and tightened by tightening rollers I8.

Each grinder I2 includes a grinding stone 19 which is fed by two magazines 20 as illustrated in FIG. 3, one located on each side of the grinding stone and adapted to discharge logs into the grinder pockets 21. In between the two magazines, there is a short conveyor 22 which may be of the chain multiple strand type including plural chains 24 powered by end rollers 26 in the conventional manner. The conveyor system also includes a plurality of gates 28 located above the magazines and adapted to be opened to discharge logs into the magazines.

The logs are fed to the conveyor system by means of a belt conveyor 30 located at from the conveyor system. In a grinder feeding system, there would normally be plural conveyor systems in parallel and each conveyor system would be fed by a separate belt conveyor 30 as illustrated in FIG. 2. The logs are fed to the conveyor system by means of a conventional pocket conveyor including chain 32 powdered by rollers 34. The pocket conveyor is also equipped with log aligning rollers 36. Such a conveyor may be of the type disclosed in US. Pat. No. 3,638,792.

The above disclosed conveyors are reversible so as to permit easy feeding of the magazines when the gates are open and also to permit piling up of several layers of logs on the beltswhen the gates are closed.

Referring more particularly to FIG. 3, there is shown two magazines for each grinder, each magazine includes a plurality of loading boxes 38 identified as boxes I to 3 on the left-hand side of the grinding stone l0 and boxes 4 to 6 on the right-hand side of the grinding stone 19. It is to beunderstood that a higher or lower number of loading boxes could be provided depending on the amount of wood which is required to be stored in the magazines. The lower loading boxes I and 4 feed the pockets 21 of the grinder whereas the upper boxes 3 and 6 are fed by metering gates 40 operated by air cylinders 42. Such metering gates are disclosed in US. Pat. No. 3,417,854 issued Dec. 24, 1968. Boxes 2 and 3 are closed by a gate 44 operated by anair cylinder 46 whereas boxes I and 4 are closed by gates 48 operated by an air cylinder 50. The logs are permitted to fall onto the metering gates 40 by the opening of gates 28 operated by air cylinders 52. It is to be understood that hydraulic cylinders could be used in place of air cylinders.

The operation of the grinder feeding system will be disclosed with reference to FIG. 4 of the drawings which illustrates a suitable circuit diagram for controlling the operation of the conveyors and of the air cylinders operating the various gates permitting to load the grinder. The control circuit is energized by a source of AC power through a toggle switch TSl and a fuse F and is set into operating condition by depressing a reset switch RST. The operation of the reset switch RST energizes relay RO through emergency stop switch STP. Relay RO locks itself operated through its own contacts RO-l and closed contacts RO-2 to apply power to conductors L1 and L2.

Forward push button PB-FR and reverse push button PB-RV control the energization of corresponding relays FR and RV which in turn control the energization of the motors (not shown) driving the conveyors. There is one set of forward and reverse push buttons for each of the conveyors of the system. In FIG. 4, only two sets of push buttons and corresponding relays have been shown for simplifying the drawings. It will also be easily understood that relays FR and RV lock operated through their own contacts FR-l and RV-l. In addition, the operation of relay FR opens contacts FR-2 to prevent inadvertent operation of relay RV when relay FR is operated and, similarly, the operation of relay RV opens contact of RV-2 to prevent inadvertent opera tion of relay FR for obvious security reasons. The energization of each set of relays FR and RV may be terminated by depressing stop switch PB-ST to stop the conveyors. It will also be noted that the energization of each set of relays FR and RV is under the control of normally open contacts R4-1 and R8-l of relays R4 and R8 and of normally closed contacts OL-l of an overload re/lay (not shown) located in the circuit of the motors driving the conveyors. Let us mention now that relays R4 and R8 are energized through conductors L1 and L5 upon closure of contacts RO-2 of the abovementioned relay RO.

It will be easily understood that the above disclosed sets of relay FR and RV control the operation of the conveyors in the forward or reverse direction so as to permit feeding of the logs into the magazines when the gates 28 are opened. In addition, the forward and re-' verse motion of the conveyors permit to pile up a predetermined number of layers of logs on the conveyors when the gates 28 are closed.

Solenoids SOL] to SOL8 and their associated relays R1 to R8 and T1 to T8 control the operation of the gate of the boxes and of the metering gates .as it will be disclosed later. In addition, the photo cells PCI to PC8 detect the presence of predetermined quantities of wood in the boxes and in the metering gates whereas pilot lights PLl to PL8 are operated by such photo cells when the required level of wood is reached.

When it is desired to load the boxes, toggle switches T51 and T52 are operated by the operator to energize solenoids SOL4 and SOL8 which control the operation of air cylinders 52 for opening gates 28. The operation of toggle switches T51 and T82 does not affect the operation of relays R4 and R8 because, at this time, the metering gates are empty and, consequently, contacts PC4-l and PC8-l associated with photo cells PC4 and PC8 are closed. The operator also operates the switch SW to its manual position MAN to energize conductor L3. The operator then pushes push buttons FBI to PB3 and PBS to PB7 to energize the corresponding solenoids SOLl to SOL3 and SOLS to SOL7 which control the operation fo air cylinders 46 opening the gates 44 ofthc boxes and air cylinders 42 which operate the metering gates 40. It will be easily understood that the operator may load all the boxes in successive order using the metering gates 40 as a means for measuring the amount of wood to be fed in the boxes.

When the boxes and the metering gates are full, the photo cells PCI to PCS are energized and the pilot lights PLl to PL8 are lighted. It will also be noted that when the photo cells PC4 and PCB are energized, contacts PC4-l and PCS-1 will be opened to deenergize relays R4 and R8 respectively and so stop the operation of the conveyors which are controlled, as mentioned previously by the forward and reverse relay FR and RV. In addition, the operation of photo cells PC4 and PC8 also close contacts PC4-2 and PC8-2 to operate timing relays R4 and T8. The operation of such timing relays open the corresponding contacts T4-l and T8-1 after a predetermined time interval to release solenoids SOL4 and SOL8 and so close gates 28 a short time interval after the conveyors are stopped. Such delay is provided to prevent any wood from blocking the closure of the gates 28.

When all the boxes and the-metering gates are full, the operator may release all the push buttons FBI to PB3 and PBS to PB7 and operate the switch SW to its automatic position AUTO to start the automatic operation of the grinder. In addition, he may release toggle switches TSl. and T52.

When one of the grinder pocket 21 is empty, the corresponding gate 48 is opened automatically by air cylinder 50, as it is commonly known with the know grinders of this type so as to permit the logs stored in boxes 1 or 4 to fall into the pocket. When box 1, for example, is empty, limit switch LS1 which is associated with gate 48, will be closed momentarily during closure of the gate. The closure of limit switch LS1 willoperate a relay Rl which is associated with the operation of cylinder 46 to open gate 44 of box 2 to unload the content of box 2 into box 1. The operation of relay R1 also closed contacts Rl-l to energize timing relay T1 through its own timing contacts Tl-l. After a predetermined time interval timing relay Tl opens its contacts Tl-l to release relay R1 and thus cause the closure of gate 44 of box 2. The closure of gate 44 of box 2 will momentarily operate limit switch LS2 to cause the opening of gate 44 associated with box 3 so as to unload the contents of box 3 into box 2. After a predetermined time interval determined by timing relay T2 of box 2, the gate 44 of box 3 will be closed and this will, in turn, operate limit switch LS3 to cause the operation of gate 42 of the metering gates 40. The-metering gates 40 will thus discharge their content into box 3. After a predetermined time interval determined by timing relay T3, the metering gates will close.

When the metering gates 40 are closed, the operator may operate the toggle switch TSl to energize solenoid SOL4 which operates gate 28. The opening of gate 28 will permit to load the metering gates as mentioned previously. When the desired level of the logs is reached in the metering gates, photo cell PC4 operates contacts PC4-l and PC4-2 to stop the conveyors and close the gates a short period of time later under the control of timing relay T4.

It will be appreciated that the automatic operation of boxes 4 to 6 is the same as the operation of boxes 1 to 3.

It will also be appreciated that the magazine in accordance with the invention permits to provide a large storage of logs due to the superposed number of boxes of the magazines. Consequently, the operator does not have to be in continuous attendance on the grinder and may therefor look after plural grinders. When he comes around a particular grinder. all he has to do is to fill the metering gates which are empty and perhaps the top boxes if he has been away for a longer period of time than usual.

The above disclosed circuit for controlling the successive discharge of the metering gates into the upper loading boxes, and the upper loading boxes into the lower laoding boxes and finally into the grinder pockets, is only given by way of example and could be designed differently.

Although the invention has been disclosed with reference to a preferred embodiment therof, it is to be understood that various modifications may be made thereto without departing from the scope of the invention defined in the following claims.

We claim:

1. A system for feeding a grinder having at least one pocket for receiving logs to be ground comprising:

a magazine located above the grinder pocket for storing logs to be fed into the grinder pocket, said magazine including a plurality of loading boxes located one above the other and each including a gate for permitting, upo actuation, one box to discharge into the box below;

b a conveyor system comprising aligned spaced conveyors free of upstanding pockets or projections located above the grinder for feeding logs to the grinder;

c a gate located in said conveyor system between spaced conveyors right above said magazine for discharging logs into said magazine;

d a metering box beneath said last named gate for measuring the amount of wood to be discharged into the upper loading box and being in the form of a generally V-shaped box for maintaining logs therein in predetermined parallel relation; and

e independent selectively reversible drive means for each of said conveyors, individually, whereby adjacent conveyors may be caused to transport logs toward each other to thereby pile logs in a multilayer stack.

2. A system as defined in claim 1, further comprising means for successively operating each of the gates of said loading boxes and said metering box for automatically feeding logs into the grinder pocket.

3. A system as defined in claim 1, wherein said conveyor system includes a flat belt conveyor and means for feeding wood onto said flat belt conveyor.

- 72 3 UNITED STATES PATENT OFFICE 9 CERTIFICATE GF CORRECTION Patent No. 3 815 763 Dated June 11 1974 Inventor(s) GEORGES BILOCQ and E. PETER J. HOOPER It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

The name of the first inventor is GEORGES BILOCQ.

Sig tied and sealed this 29th day of October 1974.

- (SEAL) v t Attest:

MCCOY M. GIBSON JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents

Claims (3)

1. A system for feeding a grinder having at least one pocket for receiving logs to be ground comprising: a magazine located above the grinder pocket for storing logs to be fed into the grinder pocket, said magazine including a plurality of loading boxes located one above the other and each including a gate for permitting, upo actuation, one box to discharge into the box below; b a conveyor system comprising aligned spaced conveyors free of upstanding pockets or projections located above the grinder for feeding logs to the grinder; c a gate located in said conveyor system between spaced conveyors right above said magazine for discharging logs into said magazine; d a metering box beneath said last named gate for measuring the amount of wood to be discharged into the upper loading box and being in the form of a generally V-shaped box for maintaining logs therein in predetermined parallel relation; and e independent selectively reversible drive means for each of said conveyors, individually, whereby adjacent conveyors may be caused to transport logs toward each other to thereby pile logs in a multilayer stack.

2. A system as defined in claim 1, further comprising means for successively operating each of the gates of said loading boxes and said metering box for automatically feeding logs into the grinder pocket.

3. A system as defined in claim 1, wherein said conveyor system includes a flat belt conveyor and means for feeding wood onto said flat belt conveyor.

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