US2784650A

US2784650A - Apparatus for making reinforced fibrous cement sheets

Info

Publication number: US2784650A
Authority: US
Inventors: Magnani Alessandro
Original assignee: FLSmidth and Co AS
Current assignee: FLSmidth and Co AS
Priority date: 1955-01-25
Filing date: 1955-01-25
Publication date: 1957-03-12
Anticipated expiration: 1974-03-12

Description

March 12, 1957 MAGNAN! 2,784,650

APPARATUS FOR MAKING REINFORCED FIBROUS CEMENT SHEETS Filed Jan. 25, 1955 2 Sheets-Sheet 1 (2,74 ATTOZ/VFXF INVENTOR. kmkdw MAM a r March 12, 1957 A. MAGNANl 2,784,650

APPARATUS FOR MAKING REINFORCED FIBROUS CEMENT SHEETS Filed Jan. 25, 19 55 2 ShtS-ShGet 2 ff p ,77

IN V EN TOR 75 F $3M e M2, M @MJ Q United States Patent APPARATUS FOR MAKING REINFORCED FIBROUS CEMENT SHEETS Application January 25, 1955, Serial No. 483,862 Claims. (CI. 9240) This invention relates to machines for producing reinforced fibrous cement sheets by the formation of a slurry of the material into a web, the deposit of successive groups of reinforcing elements upon the web for incorporation therein during its formation, and the severing of the web transversely between the groups of elements to form sheets. More particularly, the invention is concerned with a novel mechanism for use in machines of the type referred to for synchronizing the operation of the depositing and severing means, so that successive groups of reinforcing elements will be spaced along the web to permit the web to be severed between them and each group of elements will be properly centered lengthwise of its sheet.

Machines for producing fibrous cement sheets are well known and a typical machine is illustrated and described in my Patent 2,592,518, issued April 8, 1952. In the patented machine, fibrous cementitious slurry is discharged through one or more nozzles upon a traveling suction support and formed into a web, which is dewa-tered as the support advances. The traveling web is subsequently cut transversely into sheets of the desired length and various cutting devices may be used for the purpose. The cutting device preferred includes a frame pivoted to swing lengthwise of the web and carrying knives above and below the web. The device is operated at intervals, depending upon the length of the sheets to be out, and, in each operation of the device, the frame swings in the direction of movement of theweb and the knives move together to cut it, after which the knives move apart and the frame swings back to its initial position. The operating means for such a cutting device must be adjustable 'tovary the length of the intervals between successive operations of the device in order to vary, the length of the sheets produced, and a form of such adjustable operating means is disclosed in my co-pending application Ser. No. 415,476, now Patent No. 2,739,483, filed March 11, 1954.

Reinforced fibrous cement sheets may be made by depositing reinforcing elements upon theweb' for incorporation therein during its formation and my Patent 2,672,076, issued March 16, 1954, discloses means for depositing reinforcing elements upon a web. One form of the patented machine makes use of reinforcing elements in the form of wires of indefinite length and draws these wires from a supply, feeds them to the web, and cuts them off 'at the desired intervals. Another machine for. depositing reinforcing elements upon a fibrous cement web is'disclosed in my co-pending application, Ser. No. 438,536, now Patent No. 2,741,955, filed June 22, 1954, and includes electromagnetic devices operated in a cycle, in which the devices withdraw from a supply a group of reinforcing :elements pre-cut to the desired length, deposit the elements upon the web, and then return to their initial positions. In the machines of both the patent and the application, the mechanisms for depositing the reinforcing elements upon the web must operate in synchronisn'i with the cutting device, in order that the web may be cut between the successive groups of elements without interference by the elements and the elements of each group will be properly placed within their sheet.

Patented Mar. 12, 1957 The present invention is directed to the provision of a novel mechanism for use in a machine for making reinforced fibrous cement sheets for synchronizing the operation of the means for depositing the groups of reinforcing elements upon the web and the severing device for cutting the web into sheets. The new synchronizing mechanism is operated in timed relation to the cutting device and it starts the depositing means upon a cycle of operation at intervals corresponding to the intervals between successive operations of the cutting device. The synchronizing mechanism can be readily modified to vary the length of the intervals between operations of the depositing means, as the length of the sheets is changed, and it provides a close control of the operation of the depositing means.

For a better understanding of the invention, reference may be made to the accompanying drawings, in which:

Fig. l is a view partly in side elevation and partly in vertical section of a machine embodying the invention;

Fig. 2 is a view in side elevation, with the casing removed, of one form of the new synchronizing mechanism;

Fig. 3 is a vertical sectional view through the synchronizing mechanism taken at right angles to Fig. 2; and

Figs. 4 and 5 are diagrammatic views showing different forms of means for operating the means for depositing the reinforcing elements.

The machine shown in Fig. l is a typical sheet forming machine, and includes a chain of connected suction boxes 10 guided in upper and lower horizontal stretches by pairs of toothed wheels 11a, 11b, wheels 1111 being driven through a speed reducing device 12 by a motor 13 to advance the chain of boxes. The boxes in the upper horizontal stretch rest upon continuously evacuated suction chambers 14 and a fabric belt 15 encircles the chain of boxes and rests on top of the boxes supported by the chambers. The boxes and belt provide a travelling suctionsupport, upon which fibrous cementitious material in slurry form may be deposited and formed into a web, which is dewatered as it travels along with the support.

The slurry may be discharged through one or more pipes 16 upon the support within a stationary frame 17 containing a driven roller 18, which distributes the slurry on the support and forms it into a continuous layer or web. If desired, the machine may include a second frame 1'7 containing forming rollers 19, between which additional slurry 20 is deposited to form a second layer, which is united with the first layer to make up the final web. The

frame 17 and rollers 19 maybe of the construction shown the fibrous sheet for incorporation therein during its formation and the depositing means are of the construction disclosed in my co-pending application Serial No. 438,536, now Patent No. 2,741,955. The elements 22 are supported in a plurality of receptacles 23, from which a group of the elements may be picked up by electro-magnetic pick-up devices 24 carried by a plurality of arms 25 mounted on a shaft 26 supported in bearings on frame work 27. Each arm 25 is connected by a link 28 to an arm 29 fast on a shaft 30 having an arm 31 connected to one end of the piston rod 32 attached to a piston within a fluid-operated cylinder 33. The cylinder is of conventional construction and is operated by a piston valve 34 (Fig. 4). The valve controls the admission of pressure fiuid from a supply line 35 to opposite ends of the cylinder through

lines

36, 37 and the valve is movable between two positions, in which it connects the supply line 35 to line 36 and opens line 37 to the atmosphere or it connects line 35 to line 37 and opens line 36 to the atmosphere.

3 A roller 38 resting on the travelling support and driven thereby drives a roller 39 through a belt 40 and roller 39 is engageable by a plurality of rollers supported in bell crank levers controlled by links 41. The links are operable through slot and pin connections by arms 42 on shaft 30 and preferably each link is connected to its pin through a spring, which provides a yielding connection. A plurality of feed tubes 43, one for each of the pick-up devices, extend from roller 39 downwardly over the top of roller 18 to a pair of rollers, of which roller 44 is driven through a belt by roller 38 and roller 45 is mounted in swinging arms and held against roller 44 by springs. Beyond rollers 44 and 45 are guide tubes 46, which terminate close to the top of the fibrous cement layer formed by roller 18.,

The web leaving the belt 15 and travelling to a table 47 is severed into sheets by a cutting device 48, which comprises a frame 49 pivoted at 50 to swing back and forth in the direction of movement of the web. The frame carries upper and lower knives operable during its movement with the web to cut the latter, after which the knives are separated and the frame returned to its initialposition. The frame has an arm 51 with a roller 52 bearing on a cam 53 on a shaft 54 in bearings in standards 55. When the shaft makes one revolution, the frame makes a complete reciprocation and effects a cut. The shaft is driven through a chain 56 by a sprocket wheel 57 on a shaft 58, which is rotated intermittently through a suitable driving device 59 operated by the continuously rotating shaft 60 driven by the motor 13 through the speed reducing device 12. The driving device 59 may be of the type shown in my co-pending application Serial No. 415,476 and include a ratchet and pawl device operating at the desired intervals to connect shafts 58 and 60 through a one-revolution clutch.

The means for synchronizing the operation of the cutting device 48 and the reinforcing element depositing means include a shaft 61 carrying a sprocket wheel 62 connected by a chain 63 to a sprocket wheel 64 on the shaft 60. Shaft 61 is mounted in suitable fixed bearings 65 and carries a sprocket wheel 66 connected by a chain 67 to a sprocket wheel 68 on a shaft 69 supported for rotation in bearings in a sleeve 70 carried by a fixed upright 71. Shaft 69 has a second sprocket wheel 72, about which an endless chain 73 is trained to hang down as a loop. In the loop is disposed a sprocket wheel 74 on a pin 75 mounted in one arm of an angle bracket 76 having its other arm connected to a counter-weight 77 movable in a vertical slot 78 in the upright 71. A switch 79 is mounted on a plate 80, which is angularly movable about sleeve 70 and may be held in the desired position by a handle 81, which can be turned to press against the fixed plate 82 extending upwardly from the upright 71. The casing of the switch has a bushing 83 for a cable 84 containing the conductors forming part of the circuit controlled by the switch.

Switch 79 has an operating button 85 movable by a lever 86 normally resting upon a bracket 87 and the lever can be swung upward to move the button to close the switch by a projection or lug 88 carried by one of the links of chain 73. Each time chain 73 makes a circuit, the lug 88 closes the switch and, after the lug has passed by lever 86, the switch opens and the button and lever resume their initial positions. In order to vary the length of the intervals between successive operations of the switch, chain 73 may be replaced by one of different length. Also, the chain may be shifted relative to sprocket wheel 72 to alter the times, at which successive cycles of operation of the depositing means are started, and exact adjustment of the starting times may be made by swinging the plate 80 angularly to change the point in the travel of lug 88, at which it engages the switch button. The angular adjustment is facilitated by the provision of a scale 89 on the plate 82 and a pointer 90 on plate 80 for reading the scale.

The mechanism for synchronizing the operation of the cutting and depositing means may include means for operating the valve 34 or mechanical means replacing cylinder 33 for operating the arms 25 of the reinforcing element depositing means. A form of means for controlling the operation of cylinder 33 is illustrated diagrammatically in Fig. 4 as including

solenoids

91, 92, which can be alternately energized and act on the stern 34a of valve 34 to move the valve in opposite directions. The solenoids are connected to a common return line 93 and a supply line 94 is connected to a contact arm 95 lying between

terminals

96, 97 connected to the

respective solenoids

91, 92, the arm being urged by a spring 98 toward engagement with terminal 96. The position of arm 95 is determined by a cam 99 on a shaft 100 driven through gearing 101 by a motor 102. One terminal of the motor is connected to the supply line 94 through a line 103 and the other terminal is connected to line 104 having a branch 105 connected to a terminal 106 of a solenoidoperated switch 107 having a second terminal 108 connected to the return line 93. Line 104 has a second branch connected to a terminal 109 engageable by a contact arm 110 urged toward the terminal by a spring 111. Arm 110 is connected to the return line 93 and it is movable away from terminal 109 by a projection 112a on a disc 112 on shaft 100.

In the operation of the forming machine, switch 85 is closed at intervals depending on the length of chain 73 and each closing of the switch energizes the solenoid of switch 107, so that terminals 106 and 108 are connected. At the end of the preceding cycle of operation of the depositing means, motor 102 was stopped by the separation of arm 110 from terminal 109 by the projection 112a on disc 112 and, when switch 107 is closed, the motor

circuit including lines

94 and 103 is closed and the motor starts to rotate shaft 100. Rotation of shaft 100 causes the projection 112a to move away at once from contact arm 110 and the arm is moved by its spring 111 into engagement with contact 109. A supply circuit through the motor is then established and includes line 94, line 103, line 104, contact 109; arm 110, and the common return line 93. Accordingly, even though switch 79 and switch 107 are opened, the motor continues to operate until shaft 100 has made a complete revolution and projection 112a on disc 112 has again separated arm 110 from contact 109.

The cam 99 has high and low arcs and, when the end of the contact arm 95 is in engagement with the high are of the cam, the arm is in engagement with the contact 97. The supply line 94' is then connected through arm 95 and contact 97 to the solenoid 92, which acts to hold the valve in the position indicated with fluid supplied to the upper end of cylinder 33, so that arms 25 are moved clockwise. At the time the motor is stopped, the end of contact arm 95 lies in engagement with the high are on cam 99 close to the end of that arc. When the motor is started, the low arc of cam 99 quickly comes into engagement with arm 95, so that the arm may be moved by spring 98 against contact 96. Solenoid 91 is thereupon energized and valve 34 is operated to cause fluid to be supplied to the lower end of cylinder 33 and its piston move, so that arms 25 swing counterclockwise. In such movement of the arms, the pick-up devices 24 enter the receptacles 23 and pick up reinforcing elements 22. At the same time, links 41 are pulled to separate the friction rollers from rollers 39. As the rotation of shaft 100 continues, the high are of cam 99 moves under arm 95 and swings it into engagement with contact 97, so that solenoid 92 is dc-energized and solenoid 91 is energized. The valve 34 is then moved to the position shown in Fig. 4 and the piston rod 32 moves into the cylinder, so that arms 25 are moved clockwise. The pickup devices then raise the reinforcing elements until the ends of the elements lie in the space between rollers 39 and their associated friction rollers and, shortly thereafter, the movement of arms 25 permits the links to move to cause the friction rollers to grip the ends of the elements between those rollers and rollers 39. The elements are then fed through tubes 43 and between rollers 44 and 45 and through tubes 46 to be laid upon the web being formed. When the motor 102 is stopped by movement of contact arm 11G away from terminal 169, the disc 99 comes to rest with the contact arm 95 engaging the high are of the cam near the end thereof, so that the cycle of operation of the depositing means is complete.

The means for depositing the groups of reinforcing elements may be operated mechanically under the control of the synchronizing mechanism, if desired, and, for this purpose, the construction illustrated in Fig. may be employed. The mechanical operating means have many.

parts in common with the operating means including the cylinder 33 and such parts are marked with the reference characters of Fig. 4 with prime marks added. The mechanical control means includes a motor 102, which drives a shaft 100 through gearing 101', and the shaft carries an arm 113 connected to an arm 32', which corresponds in function to the element 32 shown in Fig. 1 and operates shaft 30, by which the arms 25 are moved. The motor is supplied with current from a supply line 94' through a line 103 and a return line 104 from the motor has a branch connected to the return line 93' through the switch 107' operated by a solenoid controlled by switch 79'. Another branch from the return line 104 leads to a terminal 109' engageable by a contact arm 110 connected to the return line 93'. Arm 110' is urged toward engagement with terminal 109 by a spring 111' and is movable away from the terminal by a projection 1l2'a on a disc 112 on shaft 100.

In the operation of the mechanism illustrated in Fig. 5 the closing of switch 79' by a lug on the chain 73 of the synchronizing means closes switch 107 and completes a circuit from the supply line 94 through line 103', the motor 102, return line 104', and switch 107 to the common return line 93', so that the motor is started. The motor was stopped by the separation of arm 110 from terminal M9 by the projection 112a on disc 112 and, when shaft 100' is rotated through a small are by motor 102, the projection moves away from arm 110' and the arm is moved by its spring 111' into engagement with termial 109. The motor then continues to operate, even though switch 107' is opened, since the return line 104' is connected through terminal Hi9 and arm 110 to the common return line 93'.

The synchronizing device described provides simple and accurate control of the operation of the means for depositing reinforcing elements upon the web in relation to the operation of the cutting device 48. The length of the intervals between successive operations of the cutting device is determined by the length of the chain 73 and can be readily changed by removing chain 73 and replacing it by another having more or less links. The time of the start of a cycle of operation of the depositing means can be made by shifting the chain relative to wheel 73 and, if necessary, by angularly adjusting plate 80. Such adjustment of the starting time of a cycle of the depositing means makes it possible to insure that the reinforcing elements will be properly positioned relative to the final sheets cut from the web. The synchronizing means thus insures that the groups of reinforcing elements will be deposited on the web at the desired intervals and prevents any interference by the reinforcing elements with the action of the cutting mechanism.

I claim:

1. A machine for producing reinforced fibrous cemen titious sheets, which comprises a traveling suction sup port, means for discharging fibrous cementitious material upon the suppc-'; and forming the material into a web, means for depositing groups of reinforcing elements upon the web for incorporation therein during its formation, means acting once in each work cycle for severing the web transversely between groups of reinforcing elements to form sheets, means for actuating the severing means at variable intervals to vary the length of the sheets produced in each work cycle, means for operating the depositing means in cycles, in each of which the depositing means deposits a single group of reinforcing elements, the operating means including a motor started by closing a switch, and means functioning in timed relation to the severing means for starting the operating means on a cycle, the starting means including an element for closing the switch and means for moving the element in a closed path to close the switch once for each circuit of the path.

2. The machine of claim 1, in which the means for moving the element in a closed path comprises a sprocket wheel and an endless chain driven by the wheel and the elements is a projection on the chain.

3. The machine of claim 2, in which the sprocket wheel is mounted on a shaft in fixed bearings and the chain hangs down from the wheel in the form of a loop and is kept taut by a second sprocket wheel lying in the loop of the chain and mounted on a pin, from which a counterweight is suspended.

4. The machine of claim 3, in which the counterweight is vertically movable in guides.

5. The machine of claim 2, in which the sprocket wheel is mounted on a shaft in fixed bearings and the switch is mounted on a plate angularly adjustable about the shaft as a center to vary the time of operation of the switch by the projection on the chain.

6. The machine of claim 1, in which the operating means include a fluid-operated cylinder controlled by a valve, which is actuated by means including a shaft rotated through a single revolution only by the motor.

7. The machine of claim 6, in which the shaft carries means for opening the motor circuit once for each revolution of the shaft.

8. The machine of claim 7, in which the valve is actuated to cause the cylinder to move its piston rod in opposite directions by respective solenoids, the shaft carries means for causing the solenoids to be energized in alternation and for part revolutions of the shaft and the shaft also carries means operable once per revolution of the shaft for opening a normally closed switch in the motor circuit to stop the motor, and the starting means operate to close a normally open switch in the motor circuit to start the motor.

9. The machine of claim 1, in which the motor rotates a shaft driving the depositing means and carrying means operable once per revolution of the shaft to open the motor circuit and stop the motor.

10. In a machine for producing reinforced fibrous cementitious sheets and having a traveling suction support, means for discharging fibrous cementitious material upon the support and forming the material into a web, means for depositing groups of reinforcing elements upon the web for incorporation therein during its formation, and means for severing the web transversely be tween groups of reinforcing elements to form sheets, the combination of a continuously operating driving shaft, a driven shaft, a speed reducing connection between the shafts, a sprocket wheel mounted on the driven shaft, an endless chain trained about the sprocket wheel and hanging as a loop therefrom, means for holding the chain taut including a second sprocket wheel within the chain and supported by the loop and a counterweight suspended from the second sprocket wheel, a projection on the chain, and a switch operable by the projection once per circuit of the chain.

References Cited in the file of this patent UNITED STATES PATENTS 862,475 Haywood Aug. 6, 1907 2,518,423 Jennett Aug. 8, 1950 FOREIGN PATENTS 699,529 Great Britain Nov. 11, 1953