Apparatus for splitting loose objects such as tree trunks

Apparatus for splitting tree trunks by forcing a splitting element into the tree trunk while manipulating the tree trunk. The tree trunk is manipulated by a grab to abut against support and to be cleft by a vehicle-mounted splitting element which is movable when actuated by a vehicle.

The subject invention concerns a method of splitting loose objects, such as 
wood or timber, in the form of e.g. large tree trunks and the like by 
constrained displacement of a vehicle-mounted, movable splitting and 
cleaving means towards a backup support during the splitting operation, 
and by handling the object by means of a grab. 
One problem encountered in reducing logs and other timber into chips is 
that a chipper can be used only with logs of comparatively small 
dimensions. In order to solve this problem logs having dimensions 
exceeding the capacity of the chipper have hitherto conventionally been 
split with the aid of wedges which are driven manually into the log to 
split the latter into smaller units that may be handled by the chipper. 
Also other solutions have been suggested, such as the use of a table on 
which the objects to be cut are deposited prior to being operated on by 
means of power-driven wedge-shaped splitting members. 
These solutions are, however, poorly adapted for mechanised and efficient 
application at the site of deposition of said objects and the principal 
purpose of the subject invention is to solve this problem. 
This purpose is achieved in accordance with the method of the invention 
which is essentially characterized by the steps of positioning one end of 
the object in abutment against preferably a rock, wall or other suitable 
backup support readily accessible and pressing said end against said 
support during the splitting operation while the object is lying on the 
ground, and by moving the splitting element along the object by driving 
the vehicle with the splitting element mounted thereon towards and along 
the object. 
A further object of the subject invention is to provide a device that may 
be used in connection with the performance of the method. 
Said further object is achieved by means of a device in accordance with the 
subject invention which is essentially characterized therein that a 
splitting element in the form of a blade presenting a cutting edge at its 
front is arranged to be supported by an utility vehicle, preferably a 
tractor with the cutting blade extending in the intended plane of 
splitting and vehicle-driving direction in order to displace the splitting 
element longitudinally relatively to the associated object. A grab, 
supported by a telescopically extensible supporting arm mounted on the 
tractor, is used to position the log.

The invention is primarily adapted to be used in connection with splitting 
logs 1 which have been cut into shorter lengths from large-dimension tree 
trunks but which invention could be used also to split other timber or 
loose objects, if desired. 
The splitting into two pieces of the loose object 1 is effected by forcing 
a vehicle-mounted severing means 2 to move relatively to the object 1, 
more by moving the splitting element 2, in the direction indicated by 
arrow 3 along the object 1 while simultaneously cooperating with the 
object so as to split the latter in two. For the purpose of preventing the 
object 1 from altering its position during the splitting operation, the 
object 1 is deposited in a manner ensuring that one 1A of its ends, abuts 
against a backup face or support 4, for instance in the form of a rock or 
a wall or other readily accessible backup. The object is pressed against 
backup under the influence of the splitting element 2 as it is displaced 
by the vehicle, while simultaneously cleaving the object 1. 
In order to achieve the movability referred to, the splitting element 2 is 
arranged to be supported by a utility vehicle 5, preferably a centrally 
articulated front loader or similar tractor. The splitting element 2 is in 
the shape of a blade having a wedge-like wood-engageable cutting edge 6 at 
its front 2A, the blade extending in the intended plane of splitting. In 
accordance with the embodiment illustrated, the splitting element 2 
extends along an essentially vertical plane but it could also have a 
different support, such as for instance a horizontal one or a combination 
of crossing cutting edges. 
Preferably, the splitting element 2 is supported, together with a grab 7 
arranged to grip and handle the object 1 in question, by means of a unit 8 
formed with coupling members 9, 10, whereby the unit 8 may be releasably 
connected to a grab attachment 11 of the vehicle 5. In the interconnected 
position of the device with the vehicle 5, the element 2 together with the 
grab 7, if used, are arranged in such a manner that they may be actuated 
and controlled with the aid of pistons or other power means 12 provided on 
the vehicle 5. 
The splitting element 2 is additionally formed with means allowing it to be 
releasably interconnected with the unit 8. Such means could include e.g. a 
bar 14 arranged for reception in a cavity 13. In accordance with the 
embodiment illustrated, the bar 14 projects rearwardly towards the unit 8 
and is attached to the upper end 2B of the splitting element 2 for 
insertion into a sleeve 15 projecting centrally from the lower end 8A of 
the unit in a forward direction. When required, the bar 14 may be secured 
in the internal cavity 13 of the sleeve 15, e.g. by means of a locking pin 
which is introduced manually through apertures 16, 17 formed in 
respectively the bar 14 and the sleeve 15. 
A support 18 which is integral with the splitting element 2 and which, in 
accordance with the embodiment illustrated, consists of a thrust rod 
projecting in a direction obliquely rearwards from the rear upper part 2C 
of the splitting element 2 towards the unit 8. By abutting against and 
resting on a bearing portion 19 at the lower part of the unit, preferably 
the lower face of the attachment sleeve 15, the support 18 is arranged to 
cooperate with the unit 8 for the purpose of preventing transfer of excess 
moment forces from the splitting element 2 to the unit 8 via the coupling 
means 13-15. 
The grab 7 may be in the form of two gripping arms 7A and 7B actuated 
either hydraulically or by some other pressure fluid. A swivel 21 or other 
suitable rotary joint that is mounted for rotary movement about the outer 
section 20A of a number of arm sections 20A, 20B, together forming a 
telescopically adjustable pivotal arm 20, supports the grab 7 in such a 
manner that the latter may be pivoted to the desired position. 
The pivot arm 20 of the grab 7 is arranged to be actuated by abutment means 
21, 22 which limit the angular movement of the arm 20 in the vertical 
direction of pivotment 23, between a lower position L and an upper 
position U. 
The unit 8 may be formed by a centrally open main frame 24 on a rear face 
24A of which the coupling members 9 and 10 are provided, preferably 
positioned at the corners of the unit, and presenting on its front face a 
preferably triangular attachment frame 25. An attachment means 26, which 
supports the gripping arm 20 for pivotable movement about a pivot shaft 
27, is formed at the upper part of the attachment frame and the main frame 
whereas coupling members 13, 15 pertaining to the splitting element 2 are 
supported at the lower parts of said frames. A stay 28 extends between 
said attachment 26 and the coupling members 13, 15. 
The abutments means 21, 22 which may be in the form of a plate having a 
protruding portion, are supported by said attachment means 26 and are 
arranged in such a manner that they may cooperate with counter-abutment 
means 29, 30, formed respectively by a portion bridging the side walls 31, 
32 of the arm and by the upper rear portion of the arm side walls. 
The coupling members 9, 10 of the unit 8 preferably are of the conventional 
kind used for releasable attachment to vehicles of other implements, such 
as buckets. The upper, hook-shaped coupling members 9 are arranged to be 
received in a protecting coupling-receiving space 33 and be hooked onto a 
gripping portion 34 of matching configuration and the lower, lug-shaped 
coupling members 10 are likewise arranged to be received in the 
coupling-receiving space 33 and be locked in position, for instance with 
the aid of a movable locking pin 35 which forms part of a hydraulically 
operated piston- and cylinder unit and which, in its extended position, is 
received in the coupling member 10 and locks the latter in position, 
together with the rest of the unit 8. 
When not supported by a vehicle 5 the unit 8 may be deposited on a bedding 
36 with the splitting element 2 preferably inserted into the bedding. In 
order to facilitate the insertion without damaging the unit 8 and also to 
avoid that the embedding force will have to be unnecessarily large, the 
bedding could consist of e.g. saw dust or other soft material. 
The splitting element 2 thus may be displaced longitudinally relatively to 
the object 1 by driving the vehicle 5 which supports the splitting element 
2 towards and along the object 1 while at the same time the object 1 is 
being cleft lengthwise. During this operation, one end 1A of the object 
will cooperate with an abutment or backup member 4 in the surroundings. 
Preferably, the grab 7 is allowed to let go of the object 1 during the 
splitting thereof but alternatively, as illustrated in the drawings, the 
length of the gripping arm 20 may be altered as the splitting progresses. 
During the splitting phase the upper abutment part 18A of the support 18 
will rest against the attachment sleeve 15 or other backup means connected 
with the frame 8 in order to distribute the force F acting on the 
splitting element 2 onto the frame 8. When the vehicle 5 has been driven 
sufficiently far for the splitting element 2 to assume a position close to 
the forwards end 1A of the object, the splitting of the latter is 
completed and the various pieces 1.sup.1, 1.sup.2 thereof may be run 
through a chipper without any difficulty. 
The splitting element 2 and the grab 7 could be controlled and actuated 
from the vehicle by means of the existing lifting arms 37, power means 12 
and grab attachment 11. 
The invention is not limited to the embodiments illustrated in the drawings 
and described in the aforegoing but a number of modifications are possible 
within the scope of the invention without departing from the invention 
idea.