US2534671A

US2534671A - Bark removing lathe

Info

Publication number: US2534671A
Application number: US790313A
Authority: US
Inventors: Haumann George
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-12-08
Filing date: 1947-12-08
Publication date: 1950-12-19
Anticipated expiration: 1967-12-19

Description

cm 19 1950 G. HAUMANN 295349671 BARK REMOVING LATHE Filed Dec. 8. 194? 4 Sheetsdhee INVENTOR. GEORGE HAUMANN ATTORNEY D860 1950 G. HAUMANN 2,534,671

' BARK REMOVING LATHE Filed Dec. 8. 194'? 4 Sheets-Sheet 2 INVENTOR. GEORGE HAUMANNv ATTORNEY Dec. 19, 1950 e. HAUMANN BARK REMOVING LATHE Filed has. 8. 194"? 4 Sheets-Sheet 3 I I i Inmnmnnnnnnnnm INVEN TOR. GEORGE HAUMAN N ATTOR N EY Dec 19, R950 6. HAUMANN 2,534,671

BARK REMOVING LATHE Filed Dec. 8. 194'? 4 Sheets-Sheet 4 INVENTOR. GEORGE HAUMAN N ATTORNEY Patented Dec. 19, 1950 UHED STATES PATENT OFFICE 11 Claims.

This invention relates to a bark removing lathe, the same being a machine for preliminary barking and surfacing of a log, preparatory to placing it in a veneer lathe in the manufacture of veneer.

The object is to replace the conventional barkers that usually waste a considerable amount of the valuable white or sap wood, which in plywood manufacture is equally as valuable as the heartwood.

Another object of the invention is to condition the surface of a log, which means to reduce surface irregularities a shaving at a time as a knife can handle it, without wasting good material; meaning to provide a machine, which when barking preparatory to placing the log in a veneer lathe will, if a relatively high hump, knot or pro ection is encountered, automatically move the conditioning knife back and limit the bite or amount of cut it takes, to prevent stalling the machine or damaging the knife or its mounting, which otherwise might be expected, as some of the knots thus encountered are extremely hard.

Still another object is to provide manual controls whereby the knife can be made to align to the taper and irregular contour of the log.

The foregoing and other objects that will be apparent, are found in the specification and pointed out in the claims.

Drawings accompany and form a part hereof, showing an operative structure for carrying out the purposes of the invention. l"he drawings are as follows:

Fig. l is a plan view of the entire machine;

Fig. 2 is an elevation of the machine of Fig. 1;

Fig. 3 is a partially broken away side elevation on the plane 33, Fig. 1;

Fig. 4 is a sectional elevation taken from the plane -l-Al, Fig. 5;

Fig. 5 is a fragmentary view in plan illustrating the piston control to be latLr described;

Fig. 6 is much the same as Fig. 5, it illustrates a bumper that is an important feature of the machine; and

Fig. 'I is a front elevation taken on the cutter blade, the carriage therefor and the means of mounting the same on the frame of the machine, partially in section taken on the plane li, Fig. 4%.

Describing the drawings in greater detail.

Numeral i represents a base that supports a frame 2. Revolubly mounted on the frame 2, is a headstock 3, and oppositely mounted is a tailstock 4, both of which need no description in detail. The headstock 3, is revolved by the motor 5, to which it is connected within the gear case 6, and both headstock and tailstock are movable by respective motors I and 8, to open up the distance between themselves to take in a log to be conditioned; indicated as present by numeral 9, Figs. 3 and 4, and closable to revolve the log in the well known manner. The lead blocks 29 and 2i are formed with cooperative integral guides 13 that work with relatively stationary parts 22 to preserve straight line operation.

The whole assembly so far described may be accurately regarded as the lathe portion of the log conditioner, the setting for the invention, and I will now proceed to describe the relatively stationary tool setup that conditions the log when it is revolved in the lathe and the tool is held against it to remove surface irregularities, and contains the novel structures that by their operation satisfy the objects of the invention.

Ihe instrument that rcmo'ves the irregularities referred to, is the knife blade Hi, the bevel angle of which, ii, is shown to be -tangent to the horizontal centernne of the log 9 in Fig. 4. The blade it is secured to the blade carrier i2, and the blade carrier 12, in turn, is rigidly mounted within the cutterhead l3. Numeral i3 has been chosen to designate the cutterhead as a whole, and includes the knife blade ill, the blade carrier i2 and other parts not specifically mentioned.

cutterhead I3, is carried forward into engagement with a log of any diameter within the capacity of the machine by the lead screws Hi and it, operated by the worm gear sets It and it, said screws operable through the belt it, by the reversible motor i9; and, as the load screws revolve they may reciprocably move the lead blocks 2.; and 2!, which slide in contact with the guides 22 and 23 made on rigid parts of the frame 2, as shown in Fig. l.

I'he following is a description of the cutterhead it and its mounting, which also incorporates a description of its mode of operation.

Leadscrews Hi and I5 are operatively mounted on the frame .2 to be revolved by worm wheels Hi and It operable by the reversible motor 19. The screws are threadably engaged with lead blocks 2;; and 21 to advance and withdraw the cutterhead 3 with respect to the perimeter of a log.

The cutterhead i3 is indirectly connected to lead blocks 23 and 24 through the

yokes

28 and 29; the yokes having straight portions which are rigid with the lead blocks and angularly bent portions overhanging the ends of the cutterhead pivotally connected to air cylinders 26 and 2'! at opposite ends by pivots 3i and 3|. The air cylinders contain pistons (not shown) and have piston rods such as 32 in cylinder 26; both piston rods being pivotally connected to the cutterhead 13 by pivot pins such as 35 at the right of center, Fig. l. The

cylinders

26 and 27 are controllably energize through throttles such as 38 and 39 through the conduits and 4|.

The cutterhead I3 is supported at both ends by arcuate projecting ribs 25, swingable in straight slots 2 formed in the lead blocks 2| (or 29) and the lead blocks are concurrently movable by leadscrews l4 and !5, which in turn are operable by the reversible motor l} operating through the belt 38 to drive the worm gear sets it and ll connected to the leadscrews I4 and 55 as shown in Fig. l.

The mode of operation will now be plain. The cutterhead is fed forward into contact with a log to be conditioned by bringing the edge of the knife H into tangential contact by operation of the leadscrews if; and 55 after the well understood fe-zd of a lathe. The leadscrews move the whole cutterhead assembly, as shown in Fig. 1, but unlike a lathe, the air cylinders and 21', when charged with air under pressure, provide a 'esilient cushion, the yielding of which can modify shocks occasioned by hitting very hard knots.

The cutterhead is floatingly held with respect to the horizontal plane but prevented from varying in the vertical aspect by the ribs and slots previously mentioned. By skillful ariation of the air pressure in the cylinders 23 and 2?, the operator will be able to make knife contact with a log surface that takes the natural taper of the log into consideration, if this is expedient, and at the same time his operation of the air cylinders will not detract from the effectiveness of the bumper 52 when it is contacted by a protuberance or knot, such as 5! (Fig. i) to prevent overloading the knife. The knot will strike the bumper and force the cutterhead back so that the knife takes a moderate cut and removes the knot by a succession of cuts without wasting valuable timber.

By virtue of the pivots 3! and 35, with a corresponding one on piston rod 32 and the conduits 4e and ii, the movement of the cutterhead i3, in a horizontal plane only, is well provided for.

Several modes of operation of the cutterhead will be at once apparent. ihe preferred one is now described. Due to the positioning of the cutting knife, the resistance of the substance of the log tends to drive it back out of cutting action. Assume that a log, Fig. 3, is making its initial revolution in the conditioning operation, a shaving S is being cut, indicated by the arrow 59; that it carries on its perimeter a knot 5!, whic is assumed to be beyond the capacity of the blade ii, to remove by passing through the base of the knot; but, the cutterhead is formed with a bumper 52, which is an integral part of or made rigid with the cutterhead l3, and contact of the knot 5i with the bumper 52 will cause the cutterhead !3 to be forced back until the depth of out, indicated at 53, Fig. 4, will be maintained. It will be presumed that the amount of air pressure carri d and available to operate the cylinders and 2's, will be less than that which would overload the cutterhead i3 even if the knot were near the center of the log and it was necessary to force back both pistons to reduce the depth of cut to what the machine would safely stand.

Obviously also, the operator stationed at the

controls

38 and 39, can not only swing the cutterhead [3 to accommodate the same to the taper of the log, but can also, to a considerable extent, control the load on the cutterhead and so manipulate the machine that the least amount of external log surface is removed that is required to condition the log.

The cutterhead is shown in what is believed to be its optimum position with respect to the log to be conditioned; that is, at the horizontal centerline of the log, so that the reaction or r thrust of the log against the cutter blade is as near straight as possible. Obviously, the action can be realized to some extent as the cutterhead is raised towards the top of the log. In the claims, the optimum position where named will not be intended to exclude any other position where a beneficial result of the semi-floating cutterhead can be realized.

For logs of a given class, the maximum depth of cut may be relatively fixed and is of course the distance between the point of the blade l8 and the lower side of the roller 55; but that depth is instantly lessened if a protuberance pushes the cutterhead l3 away by contacting the bumper 52 as explained, and several revolutions of the log may be necessary to dispose of the protuberance. This is under control of the operator by the

valve

38 and 39, and operation of the lead screws Hi and i5. When reducing a knot by successive cuts, he backs off the lead screws so that the log body is not reduced while successive cuts are removed from the knot.

Having fully explained the advantages of my semi-floating cutterhead for a lathe type log conditioner, the manner of its construction and its mode of operation, what I claim as new and desire to secure by Letters Patent, is:

l. A log conditioner of the lathe type wherein a log is held'between head and tail stocks and revolved against a cutting implement comprising a frame, revolving head and tailstocks operably mounted thereon, a cutterhead movable towards and away from a log held between said head and tailstocks, leadscrews operably 'mounted on said frame, lead blocks threadably engaged by said leadscrews, means for revolving said leadscrews, yokes made rigid with said lead blocks and overhanging the rear sides of said cutterhead at the ends thereof, air cylinders with piston rods therein pivotally connected between said overhang of the yokes and said cutterhead,'iiuid ressure conduits connected independently to said air cylinders and independent manual control throttles for said conduits.

2. A log conditioning machine of the lathe type wherein a log is revolved against a cutter implement, having in combination there' "th a semifloating cutter head, lead screw operated means for bringing said cutter head into operative contact with a log, characterized by a plurality of air cylinders positioned between said lead screw operated means and said cutterhead whereby the attack of the cutterhead against the log is determined by the amount of pressure that the air cylinders deliver to the cutterhead in excess of the reaction force that the revolving log delivers against the cutterhead.

3. A cutterhead for a lathe type of log conditioner wherein a log is to be conditioned by re volving against a relatively stationary blade, comprising a cutter head, a cutting blade carried thereby, a semi-floating mounting for said cutterhead that permits unequal advance or retraction of the cutterhead within desirable limits, lead screw means for advancing the cutterhead to condition a log by removing parts of its surface and air cylinder means positioned between said leadscrew means and said cutterhead, operably connected thereto with control means therefor, to effectively cushion the attack of the cutting blade against the log proportionately to the air pressure that is within said air cylinders.

4. The combination as claimed in claim 3 and including a bumper made rigid with the said cutterhead and positioned in advance of the blade to contact a protuberance before it reaches the blade, said bumper effective upon contact with such protuberance on the log to drive the cutterhead back to reduce the amount of a forthcoming cut on said protuberance.

5. A log conditioning machine comprising a base, a frame mounted on said base, revoluble headstock and tailstock means revolubly mounted on said frame, a pair of leadscrews mounted on and supported on the frame normal to the axis of the head and tail stocks, an elongated semifloating cutterhead indirectly responsively operable by said leadscrews to attack or withdraw from the log, air cylinders directly connected to said cutterhead in cushioning relationship be tween said leadscrews and cutterhead and independent manually operable control means for said air cylinders.

6. A machine for conditioning 10g surfaces prior to cutting them into veneer for veneer manufacture, comprising a base, a frame mounts thereon, opposed coaxial head and tail stocks revolubly mounted on said frame, an elongated semi-floating cutterhead spaced from and substantially in parallelism with said frame, leadscrews and leadscrew operated means mounted on said frame in normal relationship to the axis of the head and tail stocks, to attack a log revolved thereby, and an air cylinder interpositioned between each end of the cutterhead and its operating leadscrew to cushion the same and effective upon selective control thereof to vary the alignment of the cutterhead with respect to the axis of a revolving log.

7. The combination as claimed in claim 6 and including a bumper plate on said cutterhead positioned in advance of the cutter part of the cutterhead which, upon being contacted by a protuberance on arevolving log, tends to throw the cutterhead out of cutting engagement with the log save for a cut of fixed amount on the protuberance.

8. A lathe type barker and. conditioner for logs having in combination therewith an elongated emi-floating cutterhead comprising a carriage portion, a cutter portion mounted on said carriage portion, a pair of spaced apart air cylinders comprising yielding means between said carriage and cutter portions, and a bumper made rigid with said cutter portion, positioned to precede the cutting part of said cutter portion to be contacted by a knot or the like, if any, thus to force the cutter portion backwards against said air cylinders to limit the cut of said cutter portion into such a hazardous knot, or the like.

9. A log conditioning machine comprising a base, a frame mounted on said base, a revoluble headstock, tailstock means revolubly mounted on said frame, a pair of leadscrews mounted on and supported on the frame normal to the axis of the head and tail stocks, an elongated semifioating cutterhead responsively operable by said leadscrews to attack or withdraw from the log with air cylinder backing means directly connected to said cutterhead in cushioning relationship between said lead screws and cutterhead and independent manually operable control means for said air cylinder backing means.

10. A log conditioning machine comprising a log lathe, a cutterhead therefor, means for advancing and Withdrawing said cutterhead, a blade holder fioatingly mounted on said cutterhead, a blade mounted thereon, air cylinders at each end of said blade holder positioned between said blade holder and said advancing means to resiliently hold said blade in contact with a log in said lathe and a bumper mounted on said blade holder positioned to contact a protuberance on a log before it contacts said blade, to overcome said air cylinders and limit the depth of cut of said blade into such protuberance.

11. The combination as claimed in claim 10, wherein the air cylinders have separate air supply control means for independent regulation.

GEORGE HAUMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 398,593 Ellis Feb. 26, 1889 675,936 Dawson June 11, 1901 1,471,450 Collier Oct. 23, 1923 1,877,013 Moore Sept. 13, 1932 2,340,513 Deuring Feb. 1, 1944 2,340,532 Jackson Feb. 1, 1944 2,411,623 Jaques Nov. 26, 1946