Woodworking – Feeder or presser
Patent
1988-06-24
1989-05-30
Bray, W. Donald
Woodworking
Feeder or presser
144 2Z, 144 3D, 144245A, 198628, B27B 3100, A01G 2308, B27L 100
Patent
active
048341568
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD OF THE INVENTION
This invention relates to a feeding device for producing a longitudinally directed relative movement between a tree stem and the device proper, comprising a breast part to be applied against the stem, and at least two separate feeding units which are movable towards and away from each other for application against opposite sides of the stem.
BACKGROUND OF THE INVENTION
In mechanised forestry, use is made of feeding devices of the type described above, both in one-grapple harvesters (processing standing trees by felling, limbing and cutting) and in twin-grapple harvesters or processors limbing and cutting trees already felled. In one-grapple harvesters, the feeding units generally consist of so-called spiked rollers, while vehicle-type rubber wheels are generally employed in twin-grapple harvesters. In recent times, attempts have also been made to use different types of endless rotary belts for this purpose. Especially promising is the type of feeding units disclosed in SE patent application 8601628-4, utilising a plurality of links provided on the outside of a rigid guide bar and together forming an endless belt-like element.
A general desire in forest machinery is to reduce the dimensions and the weight of the components used, including the feeding units. However, this desire gives rise to problems in such cases where the harvester should be uesd for both large and small trees since the feeding units must then be designed with an exceptionally large width to be able to process trees within the entire dimensional range which in practice goes from about 40 mm (small trees from thinnings) up to 400-500 mm (full-grown trees from final fellings).
BRIEF ACCOUNT OF THE INVENTIVE CONCEPT
The present invention aims at solving the above-mentioned problems by providing narrow, conveniently operated feeding units in harvesters for processing tree stems of highly varying diameters. According to the principle of the invention, this is achieved in that each feeding unit is mounted on a holder which is connected to a frame carrying or forming said breast part, by means of a parallel arm system comprising two arms each connected to said holder and said frame by joints whose axes of rotation extend at an acute angle, particularly 45.degree., to the axes of rotation of said feeding units, and that a piston and cylinder assembly is mounted in a conventional manner between diagonally opposite joints in said parallel arm system for pivoting said arms relative to said frame for automatically centring the device relative to the stem irrespective of varying stem diameters.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
In the drawings,
FIG. 1 is a perspective view of a simplified model including the essential components of the invention,
FIG. 2 is a side view of the same model, and
FIG. 3 is a top plan view illustrating the function of the model or device during feeding of a tree stem.
DETAILED DESCRIPTION OF THE BASIC FEATURES AND OPERATION OF THE INVENTION
In FIG. 1, reference numeral 1 generally designates a frame which in practice may be included in a harvester of the one-grapple or the twin-grapple type and be tiltably mounted on e.g. the crane tip of a wheel-mounted forest machine. The frame is associated with two rounded seats or engagement means, 2, 2' which together form a so-called breast part to be applied against a tree stem in connection with the application of two feeding units 3, 3' against the stem (for application against standing trees, the device is held in the upright state as shown in FIG. 1, while for application against lying trees, the device is turned 90.degree.).
The two feeding units 3, 3' may advantageously be of the type disclosed in greater detail in SE patent application 8601628-4. Thus, each feeding unit comprises a guide bar-like, rigid frame element 4 along the perifery of which there are provided a plurality of links 5 which together form an endless belt-like feeding element. At one end of the guide bar element 4, there is provided a driving gear whe
REFERENCES:
patent: 3763905 (1973-10-01), Hamilton et al.
patent: 4515192 (1985-05-01), Eriksson
patent: 4742854 (1988-05-01), Forslund
Bray W. Donald
OSA AB
LandOfFree
Tree stem feeding device for timber harvesters does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tree stem feeding device for timber harvesters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tree stem feeding device for timber harvesters will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2145339