US2408488A - Method of perforating gypsum lath - Google Patents

Description

Oct. 1, 1946. L. N. SO'RENSEN 2,408,488

METHOD OF PERFORATING GYPSUM pm;

Original Fi led June 8, 1939 4 Sheets-Sheet 1 1946. L. N. SORENSEN 2,408,488

' METHOD OF PERFORAIING GYPSUM LATH Original Filed June 8, 1939 4 Sheets-Sheet 2 Oct. 1, 1946. SQRENSEN I i I 2,408,488

METHOD OF PERFORATING GYPSUM LATH Original Filed June 8, 1939 @2022 zawa/"enaefi/ 4 Sheets-Sheet 3 Oct. 1, 1946. L. N. SORENSEN 2,408,488-

METHOD OF PERFORATING GYPSUM LATH Original Filed June 8, 19 39 4 Sheets-Sheet 4 A Patented Oct. 1, 1946 NIETHOD OF PERFORATIN G GYPSUM LATH Louis N. Sorensen, Port Clinton, Ohio, assignor to The Celotex Corporation, Chicago, 111., a corporation of Delaware Original application June.

278,212. Divided and this 8, 1939, Serial No. application August 27, 1941, Serial No. 408,430

9 Claims.

This invention relates to the method of perforating gypsum lath or the like in the ordinary course of manufacture and article resulting therefrom, so that when the finished lath are delivered from the last or drying operations no further operation is needed before the lath is ready for use.

Heretofore the perforating operation has generally taken place after the lath have come through the dryer and have been bundled prior to shipment; the operation has been done by means of gang drills which leave considerable dust in the packaged lath.

An object of this invention is to provide a perforated gypsum lath which is free from dust; this is highly desirable as the dust falls into the eyes of the mechanic applying the lath; this particularly is true when the lath are being applied to ceiling joists.

Another object of this invention is to provide a means whereby the lath to be perforated is moved forward at intervals or steps to permit the perforating operation while the lath is at rest in the machine during the forward steps.

Still another object is to provide a means whereby the plugs cut from the lath, may be removed after the perforation is completed.

These and other objects may be seen and noted from the following specifications and its accompanying illustrations, in which:

Fig. 1 is a side elevation of the device and the carrier or conveyor upon which the lath moves. Fig. 2 is an enlarged top plan view of the perforator partly cut away,

Fig. 3 is an enlarged side elevation of the perforating device, partly in section, the cutting position of the knives being indicated by the dotted lines.

Fig. 4 is a view similar to Fig. 3 but with the knives in the retracted position and the slide in the forward position removing the plugs.

Fig. 5 is an enlarged fragmentary section showing one of the knives as the perforation is completed and the plug thrust within the throat of the knife.

Fig. 6 is a similar view to Fig. 5 but with the knife retracted and the plug about to be pushed from the top of the rod.

Again referring to the drawings a chain It] is mounted over rolls H as illustrated in Fig. 1; adjacent a conveyor of which the driven rolls l2a are a part; the idler rolls I 2 serve to support the lath on its journey through the perforator. Cross bars l3 are secured on the chain the periods between A chain 15 drives sprockets l6 and I! to which.

are secured pivotingcrank arms l8 and I9 respectively, said crank arms being secured eccentrically upon the sprockets l6 and I1 which are secured within a frame 20 on a bearing mount 2|.

A driven sprocket22 is secured on a shaft23 which is driven by means of a chain and clutch (not shown) from the main board machine drive. The chain I5 is mounted on the sprocket 22.

A Wheel 25 is rigidly secured to the outer end of the shaft 23 and has a short crank arm 26 eccentrically secured to the face thereof on a pivot pin 21, and said arm 26 has a plate 28 secured thereon at its opposite end and a notch 29 therein, thus as the sprocket 22 and wheel 25 revolve with the shaft 23, the short crank arm 26 moves in an eccentric manner against the face of the wheel 25, pivoting on the pin 21, and the free end of the arm on which the notched plate 28 is secured moves back toward the frame 20 until the revolution of the wheel causes said arm to again slide forward whereupon the notch 29 therein engages a lug l4 and moves the chain Illa forward approximately one foot.

The chain 10a drives a sprocket A which in turn drives a chain Mb which engages the sprocket B causing the chain Ill to move forward in steps of one foot or any other predetermined distance. Lath are delivered by means of a driven roll lZa to the idler rolls I2 where they are engaged by the bars I3-one of which is at each end of the lath to insure its even travel through the perforator.

As the rotationof the wheel 25 continues the notched end of the arm 26 moves away from the lug l4 and the motion of the chains l0, Illa, and lb ceases until the operation is repeated. This causes an intermittent movement of the lath 30 as it travels through the perforating machine; the synchronizing of the retraction of the short crank arm 26 with the upward thrust of the crank wheels [6 and I1 causes the perforation of the lath during thatinterval when the chain Ill carrying the lath 30 through the perforator, is not moving forward. I

The long crank rods l8 and I9 are pivotally attached at the top thereof to a plate 3| through bearings 32. Rollers 33 mounted on bars 34 move up and down on the frame 20 and keep the perforating machine in a vertical plane.

Rods 35 mounted on the plate 3| through sleeves to serve to keep the plate in alignment with a fixed die plate 31 secured to the frame 20 thereabove, the sleeves 39 being secured to the plate 3! by bolts 35.

The rods 35 pass through bearing sleeves 35 secured to the top surface of the fixed die plate 31 by bolts 49, and oil cups 4! lubricate the sliding bearing sleeve 36.

Secured rigidly to the plate 3! through sleeves 42 are circular perforating knives '23, and said knives are fastened to the plate 3! by means of a bolt "H and lock nut 12. Th bolt a l passes through the plate "iii to which the knife is welded, and engages in the bottom of theknife plate 3|. The circular knives slide up and down on stationary rods 64 secured to a fixed plate secured to the frame Eli.

The die plate 37 has apertures 4E therethrough directly above the knives 23 and registering therewith. Plugs ll extend into the apertures 46 and are held in place by means of a plate 59 to which they are fastened by means of lock nuts so. Bolts 59 secured through the plate #39 are screwed into the die plate 3? and are retained by lock nuts 75 asshown in Fig. 4 to secure the plugs t? in a set position within the aperture es.

The apertures it are of such diameter as will allow the circular perforating knives 3 to project therein, whereas the plugs M are small enough to fit within the throat of the knive (i3.

. Thus as the knives $3 pass through the gypsum lath 3B, the circular plug or cutting 5! cut therefrom is thrust downward into the throat of the. knife 43 by the downwardly projecting end of the plug M as the knife enters the aperture at. This results in a cleanuniform cut with the edges of the hole being smoothed by the troweling action of the knives as passing through them.

On the downward stroke of the perforating mechanism, the rods Mi thrustin upward through the knives 43 as the said knives move downward, push the circular plugs 5! out of the throat of the knives ea.

As the perforating assembly moves downward an extension arm 52, which is slotted at 53 to encircle a rod 5 3, strike-s a nut 55 secured on the end of said rod, which is a part of a lever operating mechanism.

, The rod to is movably secured to one end of the balancing lever 56 suspended on a-pivot post or hearing 5'! mounted on a plate 58 and suspended within the frame 28 and secured thereto by any suitable means.

Movably secured to the opposite end of the ba lancing lever 55 is a second rod 59, to the lower end of which is secured a weight 5%. A pivoting angular lever (ii is secured on a pivot pin 52 mounted through the rod 59 above and adjacent to the weight 69 The center portion of the pivoting angular lever BI is pivotally secured on a pin 63 mounted through a, bearing bracket 64 secured to the frame 26, the angular leg filo projecting downwardly within an aperture 55 in a slide 65.

The slide 6% is slidably secured through split guides 61 secured to the die plate 31 and projecting downwardly therefrom, and cross bars 68 are secured between the side bars of the slide 66; thus as the extension arm 52 strikes the nut 55 on the rod 5 the balancing lever 56 dips downward at that end, causing the rod 59 to move upward vertically. this draws the pivoting angular lever 6i upward, the angular leg 6la projecting within the aperture es in the slide 6% isthus thrust forward to a vertical position as shown in Fig. a and the slide i thus drawn forward, the cross bars 68 brushing the circular plugs 55 from the rods 44.

When the pressure is released on the nut 55, by the perforating mechanism again moving upward, the weight (it pulls the'rod 59 downward to counterbalance the balancing lever 58 and the slide 66 moves back to its original position with the cross bars out of the path of the knives 43.

Rails 69 secured to the frame by any suitable means such as an angular plate 69a, as shown in Fig. 3, apertures 691) being provided therein to allow the passage of the knives G3 I therethrough support the lath 39 in the perforator.

The operation is evident from the above description but may be briefly stated as follows: The laths or pieces of plaster board 39 are advanced step by step through the perforating machine. When the feed is stopped the sliding plate 3!, operated by the connecting rods l8 and I9 slides up carrying with it the tubular knives 43 which cut the disks 5| from the lath, as illustrated in Fig. 5, the plugs 41 acting to force the cuttings into the bore of the knives or cutters. When the plate 3i descends the cutters are retracted and the fixed rods M eject the pieces 5! from the knives as shown in Fig. 6, and then by the lever mechanism the frame 66 is shifted laterally and its bars 68 dislodge thepieces from the top of the rods 44, as indicated in Fig. 4. The operation is then repeatedfor the next rows of perforations, and so on indefinitely.

The preferred method which I prefer to use in forming my novel perforated lath wherein the perforations are troweled smooth is to first form the lath on the lath forming machine as at C. The lath after it has been formed is allowed to set as it travels on the conveyor l2a. The conveyor [2a is of such length that the time it takes for the lath to travel from the lath forming machine to the lath perforating machine, the lath has had time to partially set the cementitious' material forming the inner lamination of the lath. Where a plurality of rows of lath are simultaneously formed on the lath forming machine, it is permissible to allow some of the lath which are not to be perforated to pass on directly into the drier D, while the lath which are to be perforated are shunted to one side of the main conveyor E20. to pass through the-lath perforating machine. The shunt conveyor system to the lath perforating machine also permits the lath to set harder so that a better finished perforation is had.

The continuous movement of the lath on the conveyor or shunted conveyor [2a is then transformed to an intermittent motion by the conveyor ll! of the lath perforating machine. The lath or plaster board is advanced step-by-step through the perforating machine. As the lath is advanced, the lath is then perforated during the period when the intermittently actuated conveyor i0 is standing still. After the lath leave the perforating machine, they are transferred from the intermittently actuated conveyor H! to the continuously moving conveyor I211. The lath then are. conveyed to. the drier where they are completely dried. It is obvious from the above disclosed method of forming a perforated lath, that a novel lath has been formed wherein the perforations are troweled smooth; and as the lath is dried, a hard smooth surface is formed within the case where the lath-are drilled.

It is evident that as'the lath is perforated, it

is also possible to form means such as partially perforated holes for the reception of nails for starting the nails into the lath or plaster board as it is erected. Referring. to Figures 1 to6inclusive, novel mechanism has been provided to partially perforate the lath asit travels through the perforator with intermittent motion. There has been provided prick punches 13' in the form of'long slender rods pointed on one end and afiixed to the plate 3| in a suitable manner such as tapping the plate 3| and threading the ends of the prick punches 13, To look the prick punches in position, lock-nuts 14 have been provided.. The angular plate 69a is provided with V apertures 15 to permit the passage of the prick punches Has the plate 3! is actuated to perforate the lath as it travels through the perforator with a step-by-step motion; It is, therefore, evi-, dent that as the plate 3! is actuated, the prick punches 13 indent the" lath 30 at 76 as indicated in Figures 2, 5 and 6. Therefore, as the perforator is actuated, it is obvious that the lath 30 will be partially perforated or indented with a series of indentations along the edge of the lath or throughout the face thereof depending upon the desired pattern of perforations and there has been indicated only a simple pattern of indentations so that the method of indenting and the apparatus may be simply described. It is evident that a more elaborate pattern of perforation may be used without departing from the scope of the invention by providing an increased number of prick punches. Similarly, there may be formed indentations or other forms of perforations which may be formed by this machine wherein the finished lath has suitable indentations or perforations for applying variou clips for erecting the lath instead of the usual nailing operation.

In the foregoing specification and in the accompanying claims, the use of the words set or hardened, in referring to the board at or about the time of punching, is to be understood as comprising the use of such words in the sense in which they are commonly used in the art involved. The set or hardening of the cementitious material at or about the time of punching refers merely to the initial set or hardening of the ocmentitious material which, with a gypsum core, results from the taking on of additional water by the calcined gypsum, Ca2SO4. /2H2O in converting to Ca2SO4.2H2O, a set or hardened condition but with the material still wet. The set or hardened condition referred to is to be distinguished from the finished pro-duct which, in its set or hardened condition, and dry, that is with the excess moisture evaporated therefrom, differs in its physical condition in that the initially set or hardened material is relatively soft and somewhat plastic, whereas the finally set, hardened and dry material is brittle, and when out, broken or crushed tends to break down to a powder or dust.

It will be understood that this invention is susceptible of embodiment in various forms, which are illustrated in the accompanying drawings and that thespecial details and methods of forming the lath herein set forth may be varied to suit particular purposes without departing from the scope of invention.

6 r This application is a division of application Serial No; 278,212 filed June 8, 1939.

What is claimed is:

1. The method of fabricating a perforated slab 2 of-building material comprising a layer of set or: hardened cementitious material adhered to surfacing sheets, which comprises the steps forming theslab, allowing th slab to partially'set, positioninga selected portion ofthe slab over a stationary plug anvil perforating the partially set slab, by a reciprocating annular cutter in cooperation with the plug anvil, and troweling the partially set cementitious peripheral of the perforation causing the periphery of the perforation to be smoothed. r I l 2. The method of perforating a slab of building material comprising a layer of set or hardenedcementitious material adhered to surfacing sheets, which comprises as steps: uniformly advancing theslab, changing the uniform motion of the slab to intermittent motion, and between intermittent movements perforating selected portions of the slab after it is intermittently advanced.

3. The method of fabricating a' perforated slab of building material comprising a layer of set or hardened cementitious material adhered to surfacing sheets, which comprises the steps: forming the slab, partially drying the slab, advancing the slab by intermittent movement and between the intermittent movements thereof perforating selected portions of the slab, causing the periphery of the perforation of partially dry cementitious material to be troweled smooth, and further drying the slab whereby a perforated slab is has with the periphery of the perforations of the slab clean and smooth,

4. The method of forming indentations for nail markings in a, slab of building material comprising a layer of set or hardened cementitious material adhered to surfacing sheets, which comprises the steps: forming the slab, allowing the slab to partially set, and indenting the partially set slab on one face, the other face opposite the indentation firmly supported whereby a pattern of indentations is formed on a surface of the aforesaid slabforming nail markings without deformation of the opposite surface of the slab opposite such indentations.

5. The method of forming indentations for nail markings in a slab of building material comprising a layer of set or hardened cementitious material adhered to surfacing sheets, which comprises the steps: forming the slab, allowing the slab to partially set and indenting the partially set slab by forcing portions of one of the surfacing sheets on one face into the partially set portion of cementitious material the other face opposite the indentation firmly supported whereby as the slab of cementitious material dries, a pattern of nail indentations is formed on one face ofthe slab without deformation of the opposite surface of the slab opposite such indentations. 6. The method of fabricating a perforated and indented slab of building material comprising a layer of set or hardened cementitious material adhered to surfacing sheets, which comprises the steps: forming the slab, allowing the slab to partially set, positioning the slab with respect to punching and indenting mechanism, the under surface thereof being firmly supported, simultaneously indenting and perforating the partially set slab, and troweling the partially set cementitious peripheral of the perforation causing the periphery of the perforation to be smoothed.

'7. The method of perforating and indenting a slab of building material into a pre-arranged pattern of perforations and indentations, which comprises: uniformly conveying the slab to be perforated, changing the motion of the slab from uniform to intermittent, positioning the slab under a punching apparatus, and supported at the point of punching and simultaneously, uniformly and intermittently perforating the slab until the slab is completely perforated and indentedinto a pre-arranged pattern of perforations and indentations.

8. The method of perforating plaster board comprising the steps; intermittently advancing a sheet of substantially wet plaster board along a support means, reciprocating a gang punch with the punching stroke thereof synchronized with the dwell period of the intermittent advance of the sheet, punching the sheet with the gang punch, receiving in cavities in the punches the plugs cut from the sheet in punching and subsequent to a punching stroke ejecting the cut out punchings from the cavities of the punches.

9. The method for perforating plaster board having a partially set cementitious core with adhered surfacing sheets which comprises the steps of positioning the plaster board on a support, intermittently advancing the plaster board along the said support, simultaneously reciprocating a plurality of annular knives to cut through the plaster board and receive in their open interiors plugs of the plaster board cut therefrom as a consequence of the reciprocation of such annular knives, the cut-out plugs then through continued reciprocatory movement of the annular knives ejected therefrom, the plaster board advanced and the annular knives reciprocated in timed relation whereby the annular knives are reciprocated only during the dwell period of the intermittent advance of the plaster board and the cut out plugs are ejected prior to the completion ofthe reciprocatory motion of the annular knives and further movement of the plaster board being intermittently advanced.

LOUIS N. SORENSEN.

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