US3000412A - Wood-wool producing machine - Google Patents

Description

p 1961 A. JASCHKE 3,000,412

woon-woon PRODUCING MACHINE Filed June 15, 1959 i W a M:

42 44 U o I I V r"? 24 United States Patent,

3,000,412 WOOD-WOOL PRODUCING MACHINE Aurelia Jaschke, House No. 198, Unterschondorf (Ammersee), Germany Filed June 15, 1959, Ser. No. 820,291 6 Claims. (Cl. 144185) For the manufacture of standard wood-wool having a filament thickness of 0.03 millimetres to 0.33 millimetres and a filament length of 500 millimetres, use has hitherto been made of machines with reciprocating plane rests driven by way of a crank gear. The rests are provided with scratching and planing knives, against which is pressed the wood to be planed.

To enable all standard specifications to be satisfied, these machines must be constructed in such manner that the requisite filament thickness remains constant over the entire filament length of 500 millimetres. These requirements, however, entail a correspondingly long and heavy slide which in consequence of its great weight in its guide bearings is subjected to considerable friction which cannot be substantially reduced even by the most careful manufacture of these guides and by the best lubrication of the sliding surfaces. This renders necessary a relatively high drive power in comparison to the effective useful output of the known wood-wool machines.

The small guide clearance and the great weight of the rests render it very difficult to form a cohesive film of v lubricant in the sliding surfaces of the guide. The guides are therefore subjected to considerable wear and frequently have to be readjusted. This readjustment is very diflicult, however, and necessitates a great deal of experience, since the wear of the guides is never distributed uniformly over their entire length. The consequence of these factors is that after a relatively short time new wood-wool machines of the known type lose their ability to manufacture extremely fine wood-wool to standards.

In order to be able to take and compensate the mass forces of the reciprocating parts, which occur at the points of reversal of the movement of the plane rest, and

permit a uniform running of the machine, the long and heavy rest in the known wood-wool machines must be connected to a correspondingly heavy fly-wheel. For this reason, the known Wood-wool machines attain a maximum speed of rotation of only 250 revolutions per minute. At higher speeds of revolution undesirable violent impacts occur in the crankpin bearing and connecting-rod bearing and disturb the uniform running of the machine and cause dancing of the plane rest in the guides. The limited useful output of known wood-wool machines due to their restricted speed of revolution can therefore be increased only by increasing the number of planing points. However, this in turn results in an undesirable increase of the rest weight, so that the disadvantages occurring as a result of the high rest weight are further increased.

In order to obtain a reduction or elimination of the reciprocating masses in wood-wool machines, a machine has been proposed the cutting surface of which is formed by the plane of a rotating disc equipped with planing and scratching knives. In these circumstances the scratching knives are disposed on another smaller disc, which is mounted rotatably and eccentrically in the said disc and which is rotatable in such manner in relation to the carrier disc on the rotation of the latter, in consequence of a planetary gear, that the scratching knives constantly assume a position in parallel relationship to one another. The said scratching knives are made to reciprocate by means of a rectilinear guide on the scratching knife disc in such manner that as they pass the wooden billet pressed against the rotating carrier disc they perform a rectilinear I or approximately arectilinear movement. This is achieved by means of a roller which is guided in a guide slot, which is disposed in the carrier disc and which generally has a circular shape but is bulged out after the style of a parabola in its region facing the centre point of the rotating carrier disc.

These known wood-wool machines having a rotating carrier disc carrying the planing and scratching knives have various disadvantages. In consequence of their parabola-like bulges, the guide slots for the reciprocation of the scratching knife box in the scratching knife disc mounted rotatably in the carrier disc can be manufactured only by means of patterns on a milling machine. The inevitable tolerances in these circumstances go far beyond the extent required for the manufacture of a standard wood-wool satisfying normal requirements. Moreover, a machine of this kind cannot produce perfectly straight cuts beyond a certain minimum length, but tends to produce reject material. This is due to the fact that the transition of the circular region of the guide slot to its parabola-like bulge occurs with a sharp bend. This bend is necessary, however, since the circular movement of the scratching knives outside the scratching region has to be converted as rapidly as possible into a rectilinear movement inside the scratching region in order to make this movement as large as possible. In consequence, in the region of the bend there is an impact stress on the guide roller and the guide track. This leads to increased wear, that is to say opening out of the guide track, and inexact guidance of the scratching knives at this point.

From the practice of wood-wool manufacture it is known that the provision of a plurality of planing knives having cutting edges projecting at diiferent distances against the piece of wood and disposed on a rotating disc with only one planing point results in failure .in the production of standard wood-wool since it is impossible to adjust all the cutting edges of the planing knives in dependency on one another to the requisite high accuracy. It is therefore necessary in wood-wool machines having a rotating disc carrying the planing and scratching knives to provide only a single planing knife, but in this way the output of the machines is greatly limited.

The object of the invention therefore is to obtain a considerable increase of the useful output in such woodwool machines by providing a plurality of scratching and planing points. To this end it is necessary that during their rotation the scratching knives should be guided rectilinearly not only once, but a plurality of times over a distance of adequate length. In a machine in which the scratching knives fastened on a guide body are capable of reciprocating in a guide means for producing a rectilinear movement in the region of the scratching points during the rotation of the carrier disc, and the means for producing the said rectilinear motion is disposed on another scratching knife disc mounted eccentrically on the carrier disc and rotatably in relation to the latter, this is achieved according to the invention by the fact that the reciprocating movement of the scratching knife carrier in the rectilinear guide means of the scratching knife disc is effected by a gear wheel which is mounted co-axially to the said scratching knife disc on the carrier disc and which on the rotation of the carrier disc is set in rotation by a fixed gear rim disposed concentrically to the axis of rotation of the said carrier disc and is connected pivotally to the scratching knife carrier by way of a connecting member in the form of a pin disposed eccentrically on the said gear wheel.

The fixed gear rim may be disposed on the periphery of a fixed wheel mounted concentrically to the axis of rotation of the carrier disc. To obtain a partially rectilinear movement of the pin and hence of the scratching knife box the eccentricity of this pin in relation to the axis of the gear wheel mounted rotatably on the carrier disc is preferably about /6 of the diameter thereof and the latter in turn half of the diameter of the fixed gear wheel, so that the path of the pin and of the scratching knives corresponds to the shape of a shortened epicycloid having two practically straight curve branches. The fixed gear rim may, however, be disposed at the inner edge of a fixed ring, which is mounted concentrically to the axis of rotation of the carrier disc and inside which rolls the gear wheel mounted on the carrier disc. To obtain the rectilinear movement of the pin the eccentricity of the latter in relation to the diameter of the gear wheel mounted on the carrier disc in this case about A of the diameter thereof and the latter is in turn a quarter of the diameter of the fixed gear ring, so that the path of the 'pin and of the scratching knives corresponds to the shape of a shortened hypocycloid having four straight branches.

With this construction of a wood-wool machine according to the invention, with a rotating disc carrying the planing and scratching knives, it is impossible for the scratching knives to deviate from the predetermined path in the form of an epicycloid or hypocycloid, since inaccuracies are completely precluded owing to the driving elements selected for the disc carrying the pin. Moreover, for the purpose of obtaining a plurality of plane cuts on the rotation of the disc only a single rotating planing knife is necessary, which can be adjusted completely independently of other planing knives and therefore quite easily. The planing knives may have any desired shape, for example have a rectilinear cutting'e dge or else be disposed on a drum which is mounted rotatably and lockably in a circular recess in the rotating carrier disc, which recess is adapted to the drum diameter. They may also 'be constructed as cup wheel knives with a circular cutting edge, which are disposed to be rotatable and axially slidable in the recess in the carrier disc.

Further features and details of the invention will be apparent from the following description of the exemplified embodiments illustrated in the drawing.

FIGURE 1 is a diagrammatic elevation of the woodwool machine with a horizontally mounted axis of rotation, only one planing point being illustrated for the sake of greater clarity.

FIGURE 2 is a cross-sectional plan view of the machine along line II-II of'FlG. l.

A disc 2 forming a contact pressure surface for pieces of wood 23 to be planed'at a planing station 17 and carrying cutting means such as planing and scratching knives is keyed on a horizontal shaft I mounted in bearings 3 and 4. Another smaller disc 5 is mounted rotatably in a recess in the disc 2 and has a gear rim 6 disposed fast at its periphery. A pinion 7 which is likewise mounted rotatably in the disc '2 meshes with the said gear rim 6 and is operatively connected to another fixed "gear rim 8 which by way of a sleeve 9 is joined fast to the housing of the bearing 3. The pitch circle diameters of the gear rims 6 and 8 are equal to one another. On rotation of the disc 2 with the shaft 1 the pinion 7 is also driven and in these circumstances rolls on the gear rim 8. In consequence the disc 5 is set into rotation, namely in such manner that two parallel guide surf-aces 10 hollowed outin said disc assume a position parallel to a datum, in the present case the horizontal, in all the positions resulting from the rotation of the disc 2, in consequence of the equal pitch circle diameters of the gear rims 6 and 8.

' Between the two guide surfaces 10 of the disc 5 is disposed a sliding rest 11, which carries scratching knives 12 which are combined in a box and which in consequence of the always horizontal position of the guide surfaces 10 are likewise horizontally aligned in all rotary positions 'of the disc 2. Rectilinear guidance of these scratching knives 12 (which is required to be parallel to the grain of the pieces of wood 23 to be planed) in the region of said pieces of wood is produced by a pin 13 which slides in a guideway defined by'parallel ribs 14 which extend perpendicularly to the guide surfaces 10. The said pin 13 is disposed on a gear wheel 15 to be eccentric by an amount a, the said gear wheel 15 being mounted coaxially with the disc 5 in the disc 2 and meshing with the gear wheel 16. The said gear wheel 16 disposed coaxially with the shaft 1 of the disc 5 is joined fast to the housing of the bearing 3 by way of the sleeve 9. Its pitch circle radius corresponds to the pitch circle diameter of the gear wheel 15. On rotation of the disc 2 about its axis 1 the gear wheel 15 rolls on the fixed gear rim 16. In these circumstances the pin 13 describes a shortened epicycloid indicated by a dot and a dash line e. In the region where planing occurs this cycloid has practically straight curve branches if the eccentricity a of the pin 13 is about of the diameter of the gear wheel 15. Calculations have shown that the exact value of the eccentricity a of the pin is 0.375 times the radius of the smaller rotating gear wheel 15.

For the practically rectilinear guidance of the pin 13, however, it is in both cases necessary that when the pin 13 is situated at the centre point of the planing station 17 its eccentricity a should be directed exactly radially to the centre of rotation 18 of the shaft 1. By this guidance of the pin over the path of a shortened epicycloid or hypocycloid, the scratching knives 12 guided by the pin 13 undergo a rectilinear or approximately a rectilinear movement in the region of the scratching or planing stations, while those in the intermediate regions perform a movement in the form of a partial circle. Given appropriate alignment of the pieces of wood 23 to be planed, the scratching knives can thus follow the grain of said pieces of wood.

A planing knife 19 provided with a straight cutting edge is disposed in a drum 21 open on one side and is joined fast to said drum by means of bolts shown diagrammatically at 20. The drum 21 is mounted rotatably in another recess in the disc 2, which recess is situated diametrically opposite the disc 5, and is clamped fast by means of bolts shown diagrammatically at 22. By appropriate angular adjustment of the drum in the disc 2 the angle 6-which produces the drawing cut of the planing knife '19-between the radius of the disc 2 and of the planing knife cutting edge, can be varied as desired and adapted to the type of wood 23 tobe planed. After the cutting off of the wood-wool filaments by the planing knife 19 the said filaments are ejected at the open rear of the drum 21 situated opposite the planing knife.

The feed of the planing wood 23 against the disc 2- is initiated by means of a cam 24 fitted over the shaft 1 of said disc, and by 'means of a lever system moved by the said cam by way of a roller 25. To this end, the roller 25 is mounted on a bell-crank lever 26, which latter'at its bend 27 is fastened rotatably on a fixed part of the machine. The end of the bell-crank lever 26 opposite the roller 25 is pressed by a tension spring 29 disposed at this end, against a bolt 28 extending vertically to said end. Said bolt 28 is slidable in its stationary mounting by means of a hand wheel in the axial direction, so that the angle lever 26 constantly pressed against said bolt by means of the spring 29 is adjustable appropriately. The roller 25 can thereby be lifted from the flat side of the cam 24 by a certain amount, so that on the rotation of the said cam it bears against the periphery of the cam only for a certain distance over the eccentric part of the cam.

A connecting rod 30, pivotally connected between the roller 25 and the centre of rotation '27 to the bell-crank lever 26, transmits the lever deflections a, which are controllable by the adjustment of the bolt 28, to a lever 31 pivoted on the other end of the connecting rod 30 and mounted to be rotatable about the axis of a drivingwheel 37a serving for the feed. Said driving wheel is nonrotatably coupled to a ratchet wheel33, which is prevented from rotating in relation to a pawl 32, by the tight contact of the latter against the periphery of the ratchet wheel 33. In these circumstances a tension spring 34 enables the pawl 32 to be pressed satisfactorily against the ratchet 33. Another pawl 35 disposed fast on the machine and having a tension spring 36 serves to prevent anti-clockwise rotation of the ratchet wheel 33.

The driving wheel 37a coupled to the ratchet wheel 33 is constructed as a bevel gear and is connected by additional bevel gears 37, 38 and 38a and two worm gears 39 and 40 to driving shafts 41 and 42 of feed rollers 43 and 44 for the planing wood 23. The feed of the planing wood is efiected on the lifting of the bell-crank lever 26 from the bolt 28 by the action of the cam 24 on the roller 25. The deflection of the lever system 26, 30 and 31 causes lever 31 to swing down about the axis of the wheels 33 and 37a so that the pawl 32 likewise causes the ratchet wheel 33 to be turned, about the bevel gear 37a coupled to the said ratchet, by a certain amount corresponding to the downward movement of the connecting rod. This rotation is stepped down by way of the appertaining bevel gear 37 connected to the bevel gear 37a and by the bevel gear 38 coupled with the said bevel gear 37, and by way of the two worm gears 39 and 40 running in opposite directions, and is transmitted to the shafts 41 and 42 of the feed rollers 44 and 43 for the planing wood 23, which is clamped between the said feed rollers by adjustment means 83 providing adjustable bearings for the shaft 41. By the contra-directional rotation of the feed 1 rollers the planing wood 23 is fed against the disc 2 or the cutting means disposed thereon, by an amount corresponding to the rotation of the said feed rollers.

When the screw bolt 28 is adjusted in accordance with the position shown in FIGURE 1, which enables the roller 25 to bear against the flat sides of the cam 24, the coarsest wood-wool is produced. If the filament thickness thereof is to be reduced, the screw bolt 28 must be turned forward towards the bell-crank lever 26 against the tension of the spring 29 by means of the hand wheel. The roller is thereby lifted away from the small radius of the cam 24 by a corresponding amount. The angle deflection a produced by the cam is thus reduced by the same amount, so.

that the drive of the bevel gear 37a produced by the rotation of the ratchet wheel 33 in consequence of its pawl 32 pressed against the periphery of the said ratchet, and the drive of the feed rollers connected by way of the said bevel gears and worm drives are reduced. The resultant reduced angle of rotation of the feed rollers 43 and 44 causes the planing wood to be fed by a correspondingly smaller amount towards the cutting means in the disc 2, so that finer wood-wool is produced with the wood-wool machine according to the invention. In this way the feed of the planing wood and hence the thickness of the filament of the wood-wool to be manufactured can be adjusted exactly.

The foregoing description illustrates one form the invention may take, but it is to be understood that modifications and variations may be made thereto without departing from the scope of the invention as defined by the appended claims.

' I claim:

1. A wood-wool producing machine comprising a rotatable main disc, a planing knife secured to the main disc at a planing station, another disc eccentrically mounted on the main disc for rotation, a rectilinear guide means on said other disc, a sliding body reciprocable in said guide means, a scratching knife secured to the sliding body, gear means interconnecting the main disc and the other disc to drive the latter disc upon rotation of the main disc so as to maintain the guide means and sliding body constantly parallel to a datum, and reciprocating means for the reciprocation of the sliding body in the rectilinear guide means at the planing station, said reciprocating means comprising a gear wheel coaxial with the other disc and rotatably mounted on the main disc, a stationary gear rim coaxial with the main disc and meshing with the gear wheel to rotate the latter upon rotation of the main disc and an eccentric pin mounted on the gear Wheel and engaging the sliding body.

2. The wood-wool producing machine of claim 1, further comprising a fixed wheel mounted coaxially with the main disc, said gear rim being provided on the periphery of the fixed wheel.

3. A wood-wool producing machine comprising a rotatable main disc, a planing knife secured to the main disc at a planing station, another disc eccentrically mounted on the main disc for rotation, a rectilinear guide means on said other disc, a sliding body reciprocable in said guide means, a scratching knife secured to the sliding body, gear means interconnecting the main disc and the other disc to drive the latter disc upon rotation of the main disc so as to maintain the guide means and sliding body constantly parallel to a datum, and reciprocating means for the reciprocation of the sliding body in the rectilinear guide means at the planing station, said reciprocating means comprising a gear wheel coaxial with the other disc and rotatably mounted on the main disc, a stationary gear rim coaxial with the main disc and meshing with the gear wheel to rotate the latter upon rotation of the main disc, the diameter of the gear rim being twice that of the gear wheel, and an eccentric pin mounted on the gear wheel and engaging the sliding body, the eccentricity of the pin in relation to the axis of the gear wheel being approximately one sixth of the diameter of the gear wheel.

4. The wood-wool producing machine of claim 3, wherein the sliding body has ribs extending perpendicular to the rectilinear guide means for the sliding body, the ribs defining a guideway for engaging the eccentric pin.

5. The wood-Wool producing machine of claim 3, wherein said rectilinear guide means is a recess in said other disc.

6. The wood-wool producing machine of claim 3, wherein said scratching knife is removably secured to the sliding body.

References Cited in the file of this patent UNITED STATES PATENTS 691,523 Bate Ian. 21, 1902 1,307,474 Baldwin et a1 June 24, 1919 1,604,158 Finsterwald Oct. 26, 1926 2,348,605 Carpenter May 9, 1944

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