Veneer lathe charger

[57] ABSTRACT

A simple linkage is provided for transferring cylindrical blocks of wood in horizontal movement from the yokes of a pre-centering cradle to the chucks of a veneer lathe. The block is transferred by a pair of chucking arms which grip the ends of the block at points off center from the lathe chucking centers. The blocks are carried by the lower ends of the chucking arms which swing in a complex movement from overhead supporting mechanism. The movements of the chucking arms are controlled by wheels rolling on a pair of cam plates and a pair of link arms which together impart approximately straight line horizontal movement to the blocks instead of an undesirable arcuate path of movement.

Claims, 4 Drawing Figures

<img file="US3752201A_D0001.tif" />

Patented Aug. 14, 1973

3,752,201

Sheets-Sheet 1

<img file="US3752201A_D0002.tif" />

Patented Aug. 14, 1973

3,752,201

<img file="US3752201A_D0003.tif" />

Patented Aug. 14, 1973

3,752,201

Sheets-Sheet 3

<img file="US3752201A_D0004.tif" />

3,752,201

VENEER LATHE CHARGER BACKGROUND OF THE INVENTION

This invention relates to a veneer lathe charger.

As the available supply of large peeler logs becomes exhausted, smaller logs must be used, increasing the number of chucking operations which must be performed to produce a given quantity of veneer. This has resulted in the development of various types of lathe loaders or chargers aimed at reducing the time required to get a new log or block into the lathe so that there will not be long interruptions in the production of veneer.

Devices heretofore proposed for this purpose have been quite complicated and expensive. Also, they have been cumbersome in their space requirements, interfering with auxiliary equipment adjacent or on the lathe and in some cases requiring excessive overhead clearance.

Objects of the invention are, therefore, to provide an improved veneer lathe charger, to provide a charger of relatively simple and inexpensive construction, to provide a compact mechanism for the purpose described which moves cylindrical blocks in a horizontal path into lathe chucks, and to provide a mechanism having swinging chucking arms which move in an approximately straight line path rather than a circular arc.

SUMMARY OF THE INVENTION

In the present construction, cylindrical blocks of wood are transferred by a pair of chucking plates which grip the ends of the blocks in off center position so as to leave the centers accessible to the lathe chucks. These chucking plates are mounted on the lower ends of a pair of depending chucking arms which swing from an overhead supporting mechanism. The path of movement of the arms is determined by wheels riding on cam plates and link arms connected with the upper ends of the chucking arms. This mechanism is very compact haying minimum clearance requirements in the space adjacent the lathe and not requiring a high overhead ⁴⁰clearance.

The invention will be better understood and additional objects and advantages will become apparent from the following description of the preferred embodiment illustrated in the accompanying drawings. Vari- ⁴$ ous changes may be made in the details of construction and arrangement of parts and certain features may be used without others. All such modifications within the scope of the appended claims are included in the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an end elevation view with parts in section, showing a veneer lathe charger embodying the invention;

FIG. 2 is an elevation view taken from the right side of FIG. 1 with parts broken away;

FIG. 3 is a view on the line 3—3 in FIG. 1; and FIG. 4 is a view on the line 4—4 in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1 the lathe 10 has a pair of chucks 11 which are movable axially to receive and grip the centers of the cylindrical block of wood B and rotate the block against the veneer peeler knife assembly 12. The sheet of veneer thus produced is discharged from the right side of the machine on a suitable conveyor, not shown. The blocks approach on an infeed conveyor IS on the left side. Conveyor 15 is arranged to deposit a block on a cradle comprising a pair of lower yokes 20 when these yokes are retracted to the lower position at 20α.

Each lower yoke 20 is mounted on a slide 21 which may be raised and lowered in a vertical guide 22 by a cylindrical 23 and piston rod 24. The yoke is laterally adjustable by a cylinder and piston unit 25. For this purpose the guide 22 is pivotally supported at 26.

In the operation of pre-centering the ends of the block, the upper side of the block is engaged by a pair of upper yokes 30. Each upper yoke 30 is mounted on a slide 31 in a vertical guide 32, the yoke being raised and lowered by a cylinder 33 and piston rod 34.

Extending between the yokes 20 and lathe 10 is a trough 35 having a core conveyor 36 to remove the core blocks remaining when the block B has been reduced to such size that no more veneer can be removed therefrom.

The lower and upper yokes 20 and 30 at opposite ends of the block are adjusted by automatic mechanism to automatically pre-center the ends of the block on the level of lathe chucks 11 and at a predetermined horizontal distance from the axis of the lathe chucks. This mechanism is well understood by persons skilled in the art and forms no part of the present invention.

The parts thus far described are conventional and will not be elaborated in further detail. The present invention involves the charger which transfers the block B from its pre-centered position on the lower yokes 20 to the lathe chucks 11 after the upper yokes 30 have been retracted to their raised positions at 30α.

The charger is mounted on a horizontal main frame 40 having a bracket 41 at each end with a pin 42 providing pivotal connection with one end of a link arm 43. The opposite ends of link arms 43 are connected to a shaft 44 in the upper portion of a charger pivot frame 45. The lower portion of charger pivot frame 45 carries a shaft 46 with a wheel 47 at each end.

Each wheel 47 rides on a cam plate 50 having a slightly upwardly inclined track surface 51 on its left end in FIG. 1 and a more steeply downwardly inclined track surface 52 on its right end. This cam plate is mounted on the main frame 40 with its highest point approximately directly under shaft 44. Above the cam plate is a similarly shaped wheel retainer plate 53. The lower portion of pivot frame 45 at each end thereof is pivotally connected at 55 with a piston rod 56 in a transfer cylinder 57. At the lower end of inclined surface 52 on the cam plate 50 at each end of the pivot frame is a shock absorber 58 on a mounting bracket 59.

Mounted on each end of pivot frame 45 is a chucking arm 60. The lower end of each chucking arm 60 carries a chucking plate 61. As shown in FIG. 4, the lower end of the chucking plate is cut back in a V-shape as indicated at 62 in order to approach as closely as possible to the lathe chuck 11. An arcuate arrangement of pointed pins 63 is arranged to support small blocks B for transfer to the lathe and a plurality of semi-circular spikes 64 is disposed on a larger arc to engage larger blocks B' in addition to the support provided by pins 63.

As shown in FIG. 3, the chucking arms 60 include plates 70 having bearings 71 and 72 to slide on the shafts 44 and 46. A bracket 73 on each plate 70 is pivotally connected at 74 with a piston rod 75 in a cylinder

3,752,201

76. Each cylinder 76 is pivotally connected at 77 with a bracket 78 on a plate 80 which is a part of the pivot frame 45. Thus, the chucking plates 60 may be pulled toward each other to grip and transfer a block to the lathe chucks 11 and then moved away from each other to release the block. IN FIG. 3 the chucking arms are in the intermediate position indicated at 60α in FIG. 1.

When a block B has been pre-centered as above described on the two lower yokes 20, the retraction of piston rod 56 will swing the chucking arms 60 to the position shown in solid lines in FIG. 1 with piston rods 75 extended. Retracting the piston rods 75 causes the chucking plates 61 to grip the ends of the block and extension of piston rod 56 rolls the wheels 47 on cam plates 50, first up the slight incline of track surface 51 and then down the steeper incline of track surface 52 to the broken line position of the chucking arms at 60h in FIG. 1. At this point the movement of pivot frame 45 is arrested by shock absorbers 58 bringing the block B to rest with its center line on the center line of lathe chucks 11 for transfer of the block from chucking plates 61 to the lathe chucks.

During this transfer movement, the center line of the block B follows on the path line 90 which departs only slightly from a straight horizontal line. Even a large 25 block as indicated at B' safely clears the core conveyor 36. The charger does not require modification of any of the conventional equipment and does not require extra overhead clearance as is necessary with long, circular arc. No part of the charger projects above the conventional upper yoke assemblies 31, 32. Further, the present charger does not interfere with core conveyor 36 as do previously proposed chucking arms which are pivoted at their lower ends and swing the 35 block in a circular arc at their upper ends.

Before the described transfer movement is initiated, both lower and upper yokes 20 and 30 are retracted to positions 20α and 30α.

It is desired to provide for field adjustment of each 40 cam plate 50 at the time of installation. Adjusting screws 91 shift cam plate 50 right or left in FIG. 1 as may be necessary to produce the desired path of travel 90 under variable conditions encountered in the field. This adjustment is made before retainer plate 53 is in- 4S stalled.