US1263357A - Machine for longitudinal grinding of wood logs. - Google Patents

Description

A. N. ANDERSEN & C. VIG. MACHINE FOR LONGITUDINAL GRINDING or woon LOGS.

APPLICATION FILED JULY 14.19l5- Patented Apr. 23, 1918.

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lemmas NICOLAY ANDERSELLOF HOUGI-ISUND, EKER, AND CHRISTIAN 'VIG, or

. SKOTFOS, NORWAY. q

MACHINE FOR LONGITUDINAL- GRINDING OF WOOD LOGS.

messes.

Specification of Letters Patent. 'Patented Apr. 23 1918.

Application filed July 14, 1916. Serial No. 109,350.

To all whom it may concern:

Be it known that we, Annnns NICOLAY Axnnnsnx, a subject of the King of Norway, residing at Houghsund, Eker, and CnIzIs'rIAN VIG, a subject of the King of Norway, residing at Skotfos, Norway, have invented certain new and useful Improvements in Machines for Longitudinal Grinding of Wood Logs; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

The present invention relates to grinding machines for longitudinal grinding of wood logs and the object of the invention is to provide a machine of this type in which the circularperiphery of the rotating grindstone will cut the fibers of the wood subjected to its grinding action in the same direction.

The advantage of longitudinal grinding in the same direction as the wood fibers consists therein that the fiber btained are longer and finer than the fibers obtained in the ordinary transverse grinding processes. This is due to the fact, that in transverse processes the unevennesses in the grinding surface will break up and cut the fibers so that the same are not extracted in their whole length.

Longitudinal grinding is mostly performed on the flat side of a grind stone. It is however clear that when grindingon the fiat side of the rotating stone the active parts of the grind stone will not all move in the same direction as the fibers, as the fibers lie in a straight line, while the several parts of the grind stone move in arcs. The ideal effect cannot be obtained in this man- On the other hand when grinding longitudinally on the cylindrical surface on the grindstone, if the wood were first to touch the grinding surface with any point between its ends, it will be seen that the part of the wood behind this point would be ground against the fibers, whereby the fibers will be broken so that the desired effect is not obtained. Therefore, in order to obtain the best grinding action,tl1e' wood must first touch the grinding surface with its rearmost end, that is, the position of the wood with regard to the grinding surface must be such that the fibers in the rearmost end of the wood form tangents to'the grinding surface.

In order to obtain this effect in grinding machines of the ordinary kind in which the grinding pockets are placed radially with regard to the grindstone, the front surface of the pressing pistons according to the present invention is arranged at a certain angle to the axis of the grinding pocket in such a manner, that, when pushed to its innermost position, the front surface of the grinding piston will touch the grindstone with its rearmost part taken in the direction of the movement of the grinding urface.

This object is attained by arran 'ing the pressing pistons in the. radial poo ets of the grinding machine at such an angle to the axis of the grinding pocket that the rearmost fibers of the wood logs as seen in the direction of movement of the grinding surface are approximately parallel to the same.

On the drawing the invention i illustrated by means of a diagrammatical sketch.

A indicates the wood logs.

B is the pressing piston, D is the pocket and C is the grindstone.

As it will be noted the pressing piston B is arranged at an angle to the walls of the pressing pocket D, and as the wood logs A are parallel to the pressing piston they will also lie at an angle to the walls and to the axis of the pocket. This angle is so chosen, that the fibers at the rearmost part Eof the logs subjected to the grinding action are substantially parallel to the grinding surface or so that the log at this point is at least not ground against its fibers.

The invention may easily be applied on old grinding machines of the usual type by changing the pistons of the same.

Although the invention is here shown as applied on a grinding machine in which the wood is ground on the circumference of the grindstone, it will however be understood that it may also be adapted on machines where the wood is ground on the flat v ides of the grind stone.

Claim:

In a machine for longitudinally grinding wood logs, the combination with a cylindrical rotatable grind stone, of a stationary pocket for the logs to be ground having its longitudinal axis in a radius of said stone and its sides parallel to said axis, and a radially movable pressure piston in the pocket having its forward end arranged obliquelytosaid axis and converging toward Games nflcthianatent may be obtained for five tent the grinding surface in the direction of movement of the latter, whereby the rearmost part of the log is first moved into contact with said surface.

In testimony that we claim the foregoing as our invention, We have signed our names in presence of two ubscribing witnesses.

ANDERS NICOLAY ANDERSEN. CHRISTIAN VIG.

Witnesses THs. BERG, M. RISER.

5 each, by addressing the Commissioner of Patents,

Washington, JR. 4?.

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