US2312884A - Dowel machine - Google Patents

Description

March 1943. M. DESPRES V 2,312,884

DOWEL MACHINE Filed July 29, 1941 I 4 Sheets-Sheet 1 March 2, 1943. M, DESPRES 2,312,884

DOWEL MACHINE Filed July 29, 1941 4 Sheets-Sheet 2 :5 Name) lDesp ei Afifimobs;

March 2, 1943. M. DESPRES DOWEL MACHINE '4 Sheets-Sheet 4 Filed July 29, 1941 L5 an Patented Mar. 2, 1943 EJNH'E'ED STATES; PATENT. OFFICE v i 2,312,884 I V DOWEL-MACHINE Marcel Despres, Grand Rapids,-Mich. Application July '29, 1941, Serial No. 404,489

's claims-l .(01. 144- 30) This invention relates to machines for pro-b ducing dowels. Dowels are short lengths cut from rods of uniform cross-section and gener-' ally each end of the dowel has a continuous beveled annular surface.

The dowels are used particularly in furniture construction and in other places where wood members are to be secured together, end portions of the dowels being inserted and glued in holes in the members which are to be connected.

My invention is directed primarily to a ma chine for producing dowels very rapidly and in large quantities from elongated rods of the I:

proper diameter. Dowels heretofore in practice have generally been cut one at a time, the rod,

being fed in periodic movements a distance equal to the length of one dowel which is severed from an end portion of the rod, there being a succeeding lengthwise movement of the rod of the dowel length distance and a severing, and these steps repeated until the rod is consumed.

With my invention the rod is fed in periodic movements but a far greater length equal to a multiple of the length of a single dowel. When Q thus fed this longer distance into the machine it is held in proper position and cut transversely to the length of the dowel, and the ends of the dowel are also beveled at one time. The severed.-

dowels drop through the machine and out of the way after which there is an immediate succeeding feeding of the rod from which the dowelsare made the same distance into the machine with a repetition of the cutting of a large number of dowels simultaneously. This greatly increases the number of dowels which,

can be produced in a given time.

My-invention is directed to novel construction for effectively producing dowels in large quantity production as described, and is concerned with...

novel means for feeding the rod and controlling the feed, for rotating the rod while it is being acted upon by the severing and beveling: saws andcutters, for moving the saws out of the way when not used, and to operative position when, they are to cut and finish the plurality of dowels and, in general, for effectively attaining very large production of dowels.

An understanding of-the invention may be had from the following description taken in conneca tion with the accompanying drawings, in which, Fig. 1 is an elevation of a machine made in accordance with my invention. 7

Fig. 2 is an end elevation of the upper portion of the-machine. Fig.3 is an-opposite end elevation thereof;

Fig. 4 is a ian, new.

Fig. 5 is atransverseyertical section through V the machine between its ends.

Figs. 6 and 7 are fragmentary transverse vertical sections throughthe upper part of the ma chine at difierent planes to better illustratexthe construction.

Fig. 8 is an elevation in detail of the feeding mechanism. v r r r Fig. 9is afragmentary elevation illustrative of the means used to rotate the rod from which the dowels are cut, and

Fig. 10 is a view showing a finished dowel-and indicating the process which is followed in pro-Q ducing the dowels with bevel-ed ends.

Like reference characters refer to like parts the proper diameter, two vertical end frames l are connected together'and spaced from each other by horizontal cross bars 5. The upper; ends of the frames 4 arereduced in widthand extended upwardly as at 6. Between and over' the upper ends of the parts 6 a horizontal bar 1 is placed and secured to provide a firm frame structure. I The dowel is fed lengthwise into the ma,-

chine over a horizontal bar B'eXtending between the ends and in-the upper .portion of the ma chine so that the freeend of. the rod may not bend downwardly to a position where it cannot be operated upon. The rod when it has been moved to a determined position in themachine is acted upon by a plurality of circular saws 9 and grooving cutters 10 mounted respectively upon hori-: zontal shafts and l2 located at opposite sides. oftheupperportion of'themachine, the sawsv and cutters being spacedthe' right distance. by

sleeves I3 around the shafts. 4

The shafts and I2 are carried at the upper ends of the generally vertical arms l4 of'bell crank levers, one adjacent each end of the ma chine for each shaft whichare mounted .upon elongated rods l5, one at each side or the ma chine and carried at their ends by the frames 4.

Said bell crank levers have outwardly extending substantially horizontal arms Hi, which at each Side of the machine are connected by a bar I! to make a unit. The arms I6 pass above shafts l8, one at each side of the machine and extending between the upper corners thereof, and mounted for rotation, resting uponcams IS on said shafts. With the rotation of the shafts the raises in the cams l9 coming underneath the arms I6 turn the bell crank levers to swing the saws 9 and grooving cutters I inwardly to engage with the rod I. The saws andcutters will be moved substantially simultaneously toward each other and, as will be later described, the rod being rotated. about its horizontal axis,

grooves are cut so as to provide the beveled ends 3 and the saws passing at least to and slightly across the axis of the rod sever the dowels therefrom producing as many dowels as,, there are saws at each operation. In practice it is desi rable that the grooving take place slightly ahea of the sawing of the rod into. dowels.

An electric motor 20.i s mo ted at a lower part of .the frame on the shaft on .whicharetwodrive pulleys 2|. The shafts l2 at (oneend are provided with pulleys 22. Endless belts 23 pass. around the pulleys 22 and the drive pulleys 2| whereby the shafts l2 with the saws and-groove ing cutters thereonare continuously operated at high speed. v

A horizontal drive shaft 24 is mounted in suitablebearings on the} ends of the'frame and extends therethrough, being equipped with a pulley 25 at one end which through a suitable belt drive may be driven from any source of power. The opposite end, of the shaft; 24 carries a sprocket wheel 26 located at the same end and above the pulleys 2| previously described. The shafts l8 at thev same. end of the frame are equipped each with a sprocket wheel 21. A single endless chain 28 passes around, all of the sprockets 26.and 21 and underneath a chain tensioning idle .sprocket 21a which is suitably connected with the sleeve 33 extends outwardly over a shaft l8 and bears upon a cam 4|. When the rise in said cam comes underneath the arm the continuously driven roller 32 comes against the rod and presses it against the idle pulley 3| whereupon the rod is moved lengthwise into the machine until the rise in the cam 4| passes and the feed roller 32 is permitted to fall away from the rod. It is evident from this structure that with each rotation of the shaft Hi there is a feeding of the rod into the machine with an interval between successive feedings. It is during said interval that the cutting saws and grooving cutters are brought into operative cutting and grooving relation with the rod which has been fed into the machine and the dowels cut therefrom.

Ateach side and at each end of the machine an elongated vertically positioned member 42 is located said members having pivotal mounts at their lower ends at 43 on the adjacent ends, 4 of the frame. Each of said :membersis widened at its upper endandeach atan upper-corner has a laterally extending lug 44. (Fig. 5) which bears against a. cam 45 on each: shaft l8. The:

members. 42 at their upper endsat each end of the machine are tended to .beforced apart by a compression spring 46 located between them (Fig. 4). Each at its upper portion and adjacent its inner edge is provided with anelongated vertical slot 41. It is evident thatthe members swing. back and forth upon their pivots 43 under the action of the cams.45 andsprings 43 during the operation of the machine.

Two bars 43 are disposed lengthwise of the" machine, one of said barsbetween the twomembers 42 at each side of themachine. said barsareequipped with rollers 49 at their ends which are received within the slots 41.. At eachend of each, bar alink 50. is pivotally connected, saidlinks extendingv downward and at their lower ends formed with H-eccentric housings to coopmountedon the adjacent end 4 of the frame.

whereb'ythe shafts |8 aredriven simultaneously andin. equal amounts. V The. dowel rod is guided through the upwardly-extending end 6 of the end, of the frameoppositethat at which the belt drive 23 and chainQdriVe 28..are..located, passing through a guidej29' (Fig. 4) andover the bar 8. Upon such bar 8 near the guide 29an arm. 33 is secured on is cast'integral therewith. The arm 3|Lis hori-- zontal (Fig. '7) and, above and on it arr-idle grooved. feeding roller 3| is mounted locatedat one side of the dowel rod At the opposite side a driven feed. roller 32 of the same ram is positioned though inclined to the. horizontal (Fig. '7).

It is secured at the upper end of a shaft, which passes in a downward direction; through a sleeve 33 which has a downwardly extending arm 34 (Fig. 8) mounted for rocking:

movement on. a short'horizontal shaft 35- andf mounted in a bearing on the adjacent end 4 of the frame. equipped with a spur pinion 31. A beveled pinion 36; is pinned totheinner end of shaft 35 andis in mesh with. a beveled pinion 38 at the.

At its outer end the shaft-351s;

lower end of the shaft which carries therollerf 32, One of the shafts |8 is equipped with a gear 39 which is in mesh with thepinion 31. The feed roller 32 is therefore continuously driven but at ahigher speed thanthe shaft l8 because o f.the.diife,rence in sizes of the-gear erate with eccentrics, 5| secured on the shaft 24.

There are four eccentrics as shown in Fig. 1.

With each complete rotation of the shaft 24 each bar .48 traverses its slots,4.'| upwardly and down:-

wardly making a completei reciprocation. As. shown in Fig. 5, the bars traverse saidslots simultaneously ,and in .oppositedirections.-

A plurality of dowel rod engaging members 52 are associated .With each of the-bars-48 extend-- ing in a vertical, direction. and-pivotally mounted at theirlowerends betweenears 53 onthebars, 48 throughwhich.a.pivot.rod 54 passes it being;

understood that a. pair,of-su ch members 52-isprovided for each ,dowelthat, iscutduringg a.

machine cycle of operations. The-members152 are held in vertical position-againstsidewise.-

movement, passing through, slots in plates, 55,

one on each of the bars-48, whichplatesextend-v horizontally outward. therefrom (Figs. 5 and- 9).;

A spring 56 betweeneachinember-52 andits bar;

48 holds the members.invertical.position-against;- the bars. Each. of. the .members 52- at; its inner; edgeis serrated with. teeth, the teeth; on one; I set or series of members. at one sideofthe doweL- rod being directed downward -andg-the. others upward asshown in Fig. 5.

With this. construction after the prescribed; length of the dowel rod;ha s-been fed'into-;the-- ,machine the rises on.the cams-45 come to the lugs 44, moving the members 42 inward towa fdz.

each other and, therefore carrying -the dowel rod engaging members 52 inwardly toward- ;each

An arm 4 0,(Fig.. 7) integralpr,per a ptly otherto comeagainst-opposite sides ofrthe red I. Reciprocation in opposite direction of the bars 48 and the members 52 carried thereby, together with the opposite positioning of the serrations or teeth on said members 52 results in a continuous rotation of the rod I. At the same time the cut-off saws 9 and the grooving cutters I are brought inwardly toward each other to engage with the dowel rod whereby the operation of severing the dowels and beveling the ends occur simultaneously with a continuous turning movement of the rod about its longitudinal axis. When the rises on the cams 55 leave the lugs M the springs 46 move the members 42 and the parts carried thereby away from each other. It is while the parts are thus separated that the feeding of the rod by the grooved feeding pulleys 3| and 32 takes place.

The dowel rod when fed into the machine will lie against the upper side of the'bar 8, and itis very desirable that the rod be lifted a short distance above such bar during the time that the dowel cutting operation occurs. For this purpose lifters are provided. At one sideof the machine stationary lifting members 57 are provided and at the other side of the machine movable lifting members Ela are 'pivotally suspended at their upper ends from a rod 58 extending between the narrow upper portion 5 of the machine underneath the bar '5. Said members 51 and 5112 include each a plurality of arms spaced from each other extending downwardly between the saws and grooving cutters. The end arms 57b of the members 5164 are extended farther downward and are offset (Fig. 6) and by the force of coiled tension springs -59 bearat their ends against cams 68, mounted upon the shafts i8, whereby with each rotation of shafts the movable arms 5% are moved toward the stationary arms by said cams and away therefrom by said springs after the rises on the cams have passed. The configuration of the cams is such that the arms are opened suddenly and immedi-- ately start to close. I I

On the arms inwardly extending lugs 63 having V-shaped notches therein extend toward each other and are located in a position that when the movable arms move toward the stationary arms said lugs engage the dowel rod and hold it at opposite sides in the notches (Fig. 5) lifting the rod above the bar 3 and holding it in a horizontal position and without parts of the rod being lower than the other parts thereof, thereby insuring that the cutting of the dowels shall be square across and substantially perfect.

In the upper extension 6 of the frame 4 opposite the guide 29 an adjustable screw 62 is mounted (Fig. 4) which serves as a stop against which the end of the dowel rod comes when it is fed into the machine, insuring that the extent of the rod fed into the machine shall be accurate and uniform and, therefore, the dowels cut shall be uniform throughout the entire operation of the machine.

With this machine as described, the rod I passing through the guide at 29 is fed into the machine by the grooved feeding rollers 3| and 32 until the rod strikes the stop at E2. Substantially simultaneous with the engagement with the stop the feeding is rendered ineffective by the cam (Fig. 7) dropping away from the arm 4!]. Thereafter and immediately following, the dowel rod turning members 52 are brought against opposite sides of the rod by the operation of the cams 45 against the lugs M, and the rod lifting members 6| are brought into engagement with opposite sides of the rod. Imniedh ately thereafter the grooving cutters Ill and the cut-off saws 9 are moved inwardly toward the rod, grooving the rod and cutting the dowels off at such grooves. When this operation is finished the saws and grooving cutters, the rod rotating members 52 and the rod lifting devices 51a, 6| move outwardly to inoperative position opening the machine for the next succeeding feeding movement of the rod I until it again strikes the stop at 62. The operation may be repeated indefinitely until the length of the rod I is used up and continued to be repeated with succeeding rods. The machine operates continuously and goes through the performance described whether or not a dowel rod is fed into the machine. It is only necessary to insert the rod into the machine a distance such that it will be engaged by the feeding rollers 3i and It is evident from the foregoing that a inachine capable of very great quantity product-ion of dowels is provided. The construction is practical and eflicient.

The invention is defined in the claims and is to be considered comprehensive of all forms of structure coming within their scope.

I claim:

1. In a machine for cutting dowels, means for feeding a predetermined length of rod equal to' the combined length of a plurality of dowels, means for stopping the rod at a predetermined position, vertical bars at each side of the rod,

means for reciprocating said bars in opposite "directions. means for alternately moving said bars toward the rod to engage therewith and away from the rod to disengage therefrom, said engagement occurring at the times between longitudinal feeding movements of said rod, said bars at their engaging edges having serrations therein oppositely positioned, whereby the rod is continuously rotated when engaged by said bars, a shaft mounted to one side of the rod having a plurality of circular saws thereon spaced from each other in accordance with the lengths of dowels to be cut, means for continuously driving said shaft, and means for alternately moving the shaft and saws thereon toward the dowel rod and away therefrom, said movements to ward the dowel rod taking place simultaneously with rotation thereof.

g 2. A construction containing the elements in combination defined in claim 1 combined with a' second shaft mounted for rotation at the opposite side of the dowel rod, a plurality of grooving disks mounted on said second shaft and spaced to lie in the same vertical planes with the cutting saws, and means for moving said shaft and grooving disks thereon toward and away from the dowel rod, said movement toward the dowel rod occurring during its longitudinal rotation.

3. In a dowel cutting machine, a horizontal guide through which a dowel rod may be inserted, a fixed grooved roller mounted to turn about a vertical axis located to one side of the guide, a second grooved roller mounted at the opposite side of the guide between which rollers the dowel rod is adapted to be inserted, a shaft on which the second roller is fixed, a pivotally mounted jouurnal bracket carrying the shaft, means for continuously driving the shaft, a second continuously driven shaft, a cam on saidshaft having a rise and an arm extending from said journal bracket to and riding against said cam, whereby the second roller may be brought against the dowel rod and pressed against the first grooved roller during the time that the rise on the cam is engaged with said arm.

4. In a dowel cutting machine, means for feeding a predetermined length of a dowel rod into the machine, a stop against which an end of the rod engages, continuously operating means for cutting the infed length of the dowel rod transversely to simultaneously cut a plurality of dowels therefrom, two pairs of vertically positioned members, one at each end of the machine, each member having an eccentric housing at its lower end, a driven shaft, eccentrics thereon within the housings of said members for reciprocating one member of each of said pairs of members upwardly simultaneously with a downward reciprocating movement of the other members and vice versa, two horizontal bars extending one between the upper ends of and connected to the membersat each side of the machine, two series of upwardly extending driving bars pivotally connected to said horizontal bars at theair lower ends, those connected to one bar being to one side of the dowel rod and those to the other at the opposite side, one of said series of bars at their inner edges having serrations extending downwardly and inwardly and the other upwardly and inwardly, and means for periodically moving said members, bars and driving bars associated therewith toward each other to engage the driving bars'with said dowel rod and rotate about its longitudinal axis. ,5. A construction containing the elements in combination defined in claim 4, said last mentioned means comprising, vertically positioned members pivotally mounted at their lower ends and each having a vertical slot therein, rollers at the ends of said horizontal bars positioned in said slots, continuously driven shafts and cams on the shafts to engage with the upper end portions of said pivotally mounted members at periods of the rotation. of said shafts to move said upper end portions toward each other.

6. In a dowel cutting machine, continuously operable feeding means for feeding a predetermined length of a dowel rod into the machine, a stop against which an end of the rod engages,

means for periodically rendering said feeding means operative and inoperative, means for rotating the rod about its longitudinal axis during the times that the feeding means is inoperative, two shafts located one at each side of the dowelrod and parallel thereto, a plurality of spaced cutting saws mounted on one shaft, a plurality of spaced grooving cutters mounted on the other shaft, bell crank levers having upwardly extending arms on which said shafts are mounted, means for driving said saw and cutter shafts, two additional driven shafts, and earns thereon, said bell crank levers having outwardly extending arms resting upon said cams, whereby the cutting saws and grooving cutters are periodically moved inwardly toward each other to act upon the rod, as specified.

'7. In a dowel cutting machine, means for periodically feeding a predetermined length of a dowel rod into the machine, a horizontal bar over which the rod is fed, two members, one pivotally suspended at its upper ends above said rod and bar and extending downwardly one to each side of the rod and bar, said members having a plurality of notched projections extending toward the bar, a driven shaft, a cam thereon bearing against said pivotally suspended member at its lower ends whereby at predetermined times in the rotation of said shaft, said notched projections are brought against the dowel rod to engage and hold it in horizontal position above said bar, and yielding means normally forcing said suspended member at its lower portions against the cams.

8. In a dowel cutting machine, means for periodically feeding a dowel rod into the machine a predetermined distance equal to the combined lengths of a plurality of dowels to be cut, continuously operated means for rotating the rod, means to bring said rotating means into operative engagement with the rod at the times between periodic longitudinal feeding movement thereof, a plurality of continuously driven saws spaced apart from each other distances equal to the lengths of dowels to be cut and mounted to rotate on an axis parallel to the length of the rod. means for alternately moving said saws toward and away from the rod, said movements toward the rod to engage therewith and cut dowels occurring at the times between the periodic longitudinal feeding movements of the rod, a plurality of rotatably mounted grooving disks located in substantially the same planes with companion cutting saws, means for continuously driving said disks and means for periodically moving the same toward and away from the rod occurring in synchronism with the movements of said cutting saws.

MARCEL DESPRES.

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