US2767748A - Apparatus for stabilizing boards emerging from gangsaws - Google Patents

Description

G. A. LOFTIN Oct. 23, 1956 APPARATUS FOR STABILIZING BOARDS EMERGING FROM GANGSAWS 2 Sheets-Sheet 1 Filed NOV. 1'?, 1954 GRADY A. LOF TIN www5/fw ATTORNEYS` G. A. LOFTIN Oct. 23, 1956 APPARATUS FOR STABILIZING BOARDS EMERGING FROM GANGSAWS 2 sheets-shea 2 Filed Nov. 17, 1954 INVENTOR GRADY A. LOF-TIN WMM ATTORNEYS 2,767,748 Patented Oct. 23, 1956 APPARATUS FOR STABILIZING BOARDS EMERGING FROM GANGSAWS Grady A. Loftin, Altavista, Va., assignor to The Lane Company, Inc., Altavista, Va., a corporation of Virginia Application November 17, 1954, Serial No. 469,460

8 Claims. (Cl. 143-157) This invention relates to vertical, reciprocating gangsaws, and in particular to apparatus adapted to control and stabilize boards emerging therefrom during the sawing operation.

Vertical, reciprocating gangsaws are well known and in widespread use. These devices commonly include power driven feed rolls, adapted to hold steady the log being sawed and to feed the log through the mill. Additionally, an infeed carriage is usually employed, mounted on rails disposed below and parallel to the infeed path of the mill, adapted to firmly engage the rear end of a log and powered to supply a major portion of the feed impetus thereto.

The sawed boards emerging from the gangsaw are prone to vibrate and bounce in vertical direction, especially during high speed operation and in the so-called double mills, and this condition if uncontrolled may result in considerable damage to the board product, or complete destruction thereof. To control the bounce of the outfed boards an outfeed carriage is commonly utilized, mounted on rails disposed below and parallel to the outfeed path of the mill. These devices may include hooks or similar elements designed to grip and firmly retain the leading end of the board bundle. In high speed operation however, and in the operation of double mills, control devices of this type are often ineffective. To assist the outfeed carriage in controlling the board bundle it is common to have one or more men physicaly ride the outfed board bundle, in the attempt to hold it down and steady until the sawing operation is completed. The utilization of these tailboys materially adds to the cost of operation, and yet may prove ineffective in extreme cases.

It is a principal object of the present invention to provide improved mechanical means for stabilizing boards emerging from a gangsaw, to minimize vibration and bouncing of the boards and prevent damage thereto and destruction thereof under all conditions of operation.

A further object of the invention is to provide apparatus for stabilizing boards emerging from a gangsaw, adapted to function eciently without adjustment in the sawing of logs andV cants of various sizes, shapes and configurations. The invention is particularly adapted to individually engage and prevent bouncing of all. the sawed boards, irrespective of holes, declivities or other irregularities in individual boards.

Another object of the invention is to provide a board stabilizing apparatus adapted to firmly control all boards throughout the sawing operation by edge contact only, without materially damaging the engaged edges.

.Yet another object is to provide a board stabilizing apparatus including power driven conveyor means to facilitate the travel of boards outfed by a gangsaw. Other objects will be in part evident, and in part pointed out hereinafter. The invention and the novel features thereof may best be made clear from the following description vand the accompanying drawings, in which:

Figure 1 is a side elevational view of a preferred embodiment of the present invention, disposed in operative relationship to a conventional gangsaw indicated by dotted lines;

Figure 2 is a top plan view of the stabilizing apparatus of Figure l, partly broken away for the sake of clarity;

Figure 3 is an end elevationalview of the device of Figure l, looking toward the right hand end thereof, and illustrating the normal position of its control fingers when not engaging boards, and

Figure 4 is a sectional elevational view of the device, taken on the line 4 4 of Figure 3.

Referring to the drawings in detail, Figure l illustrates a conventional vertical, reciprocating gangsaw 10, mounted below and extending above the work oor 12. As will be understood, the gangsaw 10 mounts a plurality of parallel, verticaly disposed saw blades 13, which are reciprocated vertically to saw a cant or log 14 into a plurality of boards 15 in a single pass through the mill. Normally a conventional infeed carriage (not shown) is disposed on the infeed vside of the gangsaw, to the left as illustrated, to engage and feed logs through the mill. As will be evident, the Vertical reciprocatory sawing action of the blades 13 inherently tends to impart vibratory vertical movement to the outfed boards 15, the effect of which becomes greater as the free length of the boards increases.

To effectively stabilize the boards emerging from the mill, according to the present invention there is provided on the outfeed side thereof a control device comprising frame 16, which includes opposed side members 17 and a plurality of transverse members extending between the side members and adapted to maintain them in generally parallel, spaced relationship. Two such transverse members disposed at the entry end of the frame are guard plate 18 and bumper plate 19.

The frame 16 is movably supported by a plurality of wheels 20, which in turn are supported and guided by tracks 22 set in the work oor 12. The tracks 22, as will be apparent, are disposed'below and parallel to the outfeed path of the control apparatus, whereby the device may be positionally adjusted therealong toward and away from the gangsaw,

Inside the frame and adjacent the bottom thereof is provided a horizontally disposed conveyor 23. The conveyor comprises a pair of longitudinally spaced transverse shafts 24 suitably journaled in the side members 17, each shaft carrying a pair of laterally and correspondingly spaced sprockets 25. A chain 26 engages each aligned pair of sprockets, and the chains are joined by a plurality of transverse channels or cleats 27 joined thereto, the cleats extending substantially the distance between frame side members and constituting an open but relatively rigid conveyor platform. Between shafts 24, a longitudinally spaced pair of beams 28 extends transversely between the frame side members, bearing above them a pair of laterally spaced and longitudinally extending slide bars 29, which extend substantially from leading to trailing sprockets, although slightly off-set therefrom. The slide bars 29 are adapted, as will be evident, to support the cleats 27 on the upper ilight of the conveyor, and their ends are downwardly curved, as at 30, to facilitate the passage of the cleats onto and olf the slide bars.

One end of the trailing shaft 24 extends through the side member 17 which supports it, and is engaged to a slip clutch 32, which in turn is driven by a motor 33, in

' order to power the conveyor. The leading shaft 24 may befmounted in tll'eside member slots 34 (see Figure l), and suitable means, such as threaded bolts 35, may be provided to' vary the longitudinal position thereof, whereby the tension'of the conveyor may be suitably adjusted.

i Above the entry yendr of the conveyor 'aplurality vof shafts 36 extend transversely between the frame side members. These shafts, which in the illustrative embodiment are four in number, are spaced from each other in both vertical and horizontal direction. As best shown in Figure 4, the shafts are stepped upwardly and rearwardly with respect to the material path, each successive shaft being offset slightly to the rear of the shaft below it. and offset vertically from the shaft below a somewhat greater distance.

From each shaft 36 depends a plurality of depending rigid fingers 37, each affixed at its upper end to a hub 38 by means of which it is pivotally suspended. The bank of fingers suspended from each shaft are arranged in side by side relationship, with minimum spacing therebetween, to Vform a substantially continuous bank of individually acting fingers. The fingers may be constructed, for example, of one inch square bar stock, in which case if successive shafts 36 are offset horizontally one inch, the successive banks will be parallel and contiguous when the fingers hang in normal position unengaged by boards.

The lower end of each finger 37, preferably, is downwardly and forwardly inclined, as at 39. The fingers of cach bank, that is the fingers depending from each shaft 36, are of equal length, and the fingers of the different banks are of different lengths. The successive banks of lingers, from front to rear, are each longer than the preceding bank, enough longer so that their lower ends 39 extend into closer proximity to the conveyor 23, whereby the lower ends of the fingers are arranged in transverse rows downwardly and rearwardly stepped.

Operation and function of the device will now be described in detail. First, the stabilizing apparatus will ordinarily be spaced from the gangsaw in accordance with the length of logs or cants to be sawed. For relatively short logs, the apparatus will be closely spaced, and for longer logs the spacing will be correspondingly greater. The spacing may be adjusted by moving the frame 16 on its wheels 20, and the device may be locked at desired position on the tracks 22 in any conventional manner, as for example by means of blocks 21 clamped to the rails adjacent the frame wheels.

For operation, the motor 33 will be energized, its speed desir-ably being such as to drive the conveyor 23 at a speed somewhat exceeding the normal work rate of the mill. With the conveyor 23 of the stabilizing device in operation, a log may be fed into and through the gangsaw li?, by means of an infeed carriage or otherwise. The outfed board bundle will progressively extend from the gangsaw until the leading end thereof passes below guard plate 18 and onto the conveyor 23 of the stabilizing device. The conveyor 23 rotates in the direction indicated by the arrow in Figure 4, and its cleats 27 rising on the forward end thereof will guide any depending boards upwardly onto the conveyor.

The boards in passing underneath the shafts 36 wilt cause some or all of the rigid fingers 37 to swing cr pivot rearwardly about the shafts from which they depend, as indicated in Figures l and 4. The width of the finger banks will normally correspond to the capacity of the mill, so that a board bundle sawed from a log of maximum width which can be handled by the gangsaw 10 may displace all fingers of any bank, whereas a board bundle of lesser width may engage only central groups of fingers. Similarly, the forward and shortest bank of fingers may be of such length as to be engaged only by a board bundle of maximum depth, whereas a board bundle of lesser depth may engage only the rearward three banks of fingers. Normally, the approach of the rearward three banks of fingers to the conveyor will be such that all are engaged by a board bundle of average or customary depth.

The fingers 37 need not correspond in width or alignment to the boards being sawed. Such alignment is not essential, since in any common case an individual board will contact at most two adjacent fingers of one bank, and an individual finger will contact at most two ad- .4 jacent boards. Each board may move freely in longitudinal direction under the line of fingers thereabove, the ngers in such case swinging freely rearwardly and upwardly in pivotal manner. Under the influence of gravity, the individually acting fingers will maintain close con tact with the boards therebeneath, rising over high spots and falling into low spots and generally following irregularities in such manner as to remain substantially constantly in contact with the board or boards. Accordingly, in passing below the shafts 36, each individual board will be engaged by an aligned row of fingers, most or all of which will be in Contact with the board at any instant of time.

The lower ends 39 of the rigid lingers 37 are formed so as to present to the boards, when the fingers are displaced rearwardly, relatively sharp points directed generally downwardly. While the boards may move freely in longitudinal direction, any tendency of the boards to bounce upwardly causes the finger ends to dig into the upper board edges, and prevent such upward movement. The provision of multiple fingers in contact with each board not only assures constant engagement, but also serves to spread the load when the board tends to bounce, thereby preventing gouging to any appreciable extent. Also, due to the relative disposition of the shafts 36, the fingers of each successive bank will in the usual case contact any individual board therebelow at a different angle, whereby vertical movement of the board is most positively precluded. In this manner, the boards are maintained in firm contact with the conveyor 23, the fingers thereabove walking along the upper edges thereof to remain always in proper position to prevent'upward movement. When the trailing end of a board bundle passes rearwardly beyond the reach of the fingers, they are free to fall under the influence of gravity to the hanging position illustrated in solid lines in Figure 4, ready to engage the following board bundle.

In the manner described the outfed board bundle will be effectively controlled and held steady at all times. The action of the stabilizing device is entirely automatic, depending only on gravity for its operation.

As will be evident, the device is adapted to function effectively without adjustment or change, on logs or cants of all sizes and shapes.

The conveyor 23 of the device contributes somewhat to the outfeed of the board bundle from the mill, and serves when the log being sawed leaves the mill blades to transport the board bundle to the rear of the stabilizing device, from which position it may be conveyed away in any suitable manner. The open construction of the conveyor permits bark and trash to fall freely therethrough, into a pit or other receptacle, which may be provided.

It will thus be seen that there has been provided by this invention a structure in which the various objects hereinbefore set forth, together with many practical advantages, are successfully achieved. As various possible embodiments may be made of the mechanical features of the above invention, all without departing from the scope thereof, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.

I claim:

l. Apparatus for stabilizing boards emerging from a gangsaw comprising a frame positioned beyond the saws and having transversely spaced slide members, a conveyor in said frame for supporting said boards, and a plurality of longitudinally offset banks of individually acting rigid fingers pivotally suspended between said side members, all fingers of each bank being of equal length and each successive rearward bank of fingers extending into closer poximity to said conveyor.

2. Apparatus as defined in claim 1, wherein the outer ends of said fingers are downwardly and forwardly inclined.

3. Apparatus for stabilizing boards emerging from a gangsaw comprising a frame positioned beyond the saws and having transversely spaced side members, a conveyor in said frame, means for driving said conveyor, and a plurality of longitudinally oliset banks of individually acting rigid lingers pivotally suspended between said side members, all lingers of each bank being of equal length and each successive rearward bank of lingers extending into closer proximity to said conveyor.

4. Apparatus for stabilizing boards emerging from a gangsaw comprising a frame positioned beyond the saws and having transversely spaced side members, a horizontal conveyor in said frame adapted to support and carry said boards away from said gangsaw, means for driving said conveyor, a plurality of shafts extending transversely between said side members above the entry end of said conveyor, said shafts being stepped upwardly and rearwardly with respect to said conveyor, and a bank of individually acting rigid lingers pivotally suspended from each of said shafts, all lingers of each bank being of equal length and each successsive rearward bank of lingers extending into closer proximity to said conveyor.

5. Apparatus as defined in claim 4, wherein the outer ends of said lingers are downwardly and forwardly inclined.

6. In combination with a vertical, reciprocating gangsaw, a stabilizing device beyond the saws, and aligned with the outfeed path, of said gangsaw, said stabilizing device comprising a frame having transversely spaced side members, a conveyor in said frame disposed below the outfeed path of said gangsaw, a plurality of longitudinally otl'set banks of individually acting rigid lingers pivotally suspended between said side members over said conveyor, all lingers of each bank being of equal length and each successive rearward bank of lingers extending into closer proximity to said conveyor, and means for adjusting the spacing between said stabilizing device and said gangsaw,

7. In combination with a vertical, reciprocating gangsaw, a stabilizing device beyond the saws, and aligned with the outfeed path, of said gangsaw, said stabilizing device comprising a frame having transversely spaced side members, a horizontal conveyor in said frame disposed below the ontleed path of said gangsaw and adapted to support and carry said boards away from said gangsaw, means for driving said conveyor, a plurality of shafts extending transversely between said side members above the entry end of said conveyor, said shafts being stepped upwardly and rearwardly with respect to said conveyor, and a bank of individually acting rigid lingers pivotally suspended from each of said shafts, all ngers of each bank being of equal length and each successive rearward bank of lingers extending into closer proximity to said conveyor.

8. Apparatus as delined in claim 7, wherein said conveyor drive means is adapted to drive said conveyor at a speed exceeding the normal work rate of said gangsaw.

References Cited in the lile of this patent UNITED STATES PATENTS 142,294 Stowell Aug. 26, 1873 411,925 Linderman Oct. 1, 1889 697,565 Thomas Apr. 15, 1902 901,889 Cummings Oct. 20, 1908 1,920,584 Osterburg Aug. 1, 1933 2,073,898 Lof Mar. 16, 1937 2,160,307 Cleveland May 30, 1939 FOREIGN PATENTS 56,229 Sweden Mar. 11, 1924

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