IE59533B1 - Improvements in or relating to sawing logs - Google Patents

Description

This invention relates to sawing logs. The invention relates especially to apparatus for supporting a number of lengths of wood so that they may be readily cut into shorter lengths and thus provide logs for use in domestic houses.

At the present time, considerable volumes of lengths of timber are becoming available from State and other commercial forests, for use in heating domestic houses. Frequently this timber is supplied in lengths of up to ten feet, and accordingly, it is necessary for these longer sections to be cut up into shorter portions so as to provide logs suitable for use in domestic hearths or domestic boilers.

It is an object of the present invention to provide apparatus which will facilitate such cutting up of lengths of timber to provide logs suitable for domestic use. It is a particular object of the invention to provide supporting apparatus for longer lengths of timber which will enable such lengths to be readily cut up into logs suitable for domestic use, in particular, by means of a handheld chainsaw.

According to the invention, there is provided support apparatus for lengths of timber to be cut into logs of relatively short axial extent, comprising a timber-accommodating portion for receiving a number of said lengths of timber, a base portion on which said timber-accommodating portion is mounted, and clamping means for retaining lengths of timber on said timber-accommodating portion, wherein said base portion includes at least one pillar means and at least one transverse member, said pillar means having an upper end at which said timber-accommodating portion is mounted, and said transverse member being disposed at an axial spacing from said upper end of the pillar means, having at least one dimension extending in a direction substantially at right angles to the longitudinal axis of said pillar means, and being securable to a stabilising base or frame in use of the apparatus.

The timber-accommodating portion of the apparatus may consist of a -2cradle structure defined by spaced apart Vee-shaped sections and at least one further member extending between said sections, said upper end of said pillar means being affixed to said further member of said cradle structure. Lengths of timber may then be loaded into said cradle to extend in a direction substantially at right angles to the plane defined by either of said Vee-shaped sections.

Said transverse member is suitably a baseplate, which may be secured to a concrete base or other frame structure.

In an especially favoured construction, said transverse member has a lower region engageable against an upper region of a circular member, for retention thereagainst by gripping means, so as to enable the apparatus to be moved about by tilting the apparatus and an attached said circular member, for rolling along manually, balanced on the rim or edge portion of the circular member.

The clamping means preferably includes a clamping chain and a locking mechanism, one end of said chain being substantially fixedly associated with a rigid member of the apparatus, and the other end of said chain being engageable by said locking mechanism for retaining the chain in tight engagement with a number of lengths of timber received in said timber-accommodating portion of the apparatus, said locking mechanism including a lever for pivoting displacement relative to said base portion and a chain-engaging member which is mounted for pivoting displacement relative to said lever, said mechanism having a first disposition in which said chain-engaging member thereof may be engaged with or disengaged from a link of the chain and a second disposition in which the chain is maintained under tension, the mechanism being displaceable between said first and second dispositions. In a favoured embodiment, an over-centre locking arrangement is provided in which the mechanism has a further disposition between said first and second dispositions in which the chain is tensioned to a greater degree than when the mechanism is in said second disposition.

In an alternative construction, the clamping means may comprise a clamping chain, one end of which is substantially fixedly associated with a rigid member of the apparatus, and the other end of which may be -3engaged by a locking means for retaining the chain in tight engagement with a number of lengths of timber received in said timber-accommodating portion of the apparatus, said locking means including a linkage having a first disposition in which a chain-engaging member thereof may be engaged with or disengaged from a link of the chain and a second disposition in which the chain is maintained under tension, the linkage being displaceable between said first and second dispositions, and an over-centre locking arrangement being provided in which the linkage has a further disposition between said first and second dispositions in which the chain is tensioned to a greater degree than when the linkage is in said second disposition.

Said end of the chain which is substantially fixedly associated with the apparatus may be linked thereto through resilient means such as a spring mounting, so that minor variations in the tension cf the chain during use of the apparatus may be accommodated.

An embodiment of the invention, together with certain advantageous modifications thereof, will now be described, having regard to the accompanying drawings, in which: Figure 1 is a pictorial view of timber support apparatus accppcLing to the invention, Figure 2 is a view of the apparatus of Figure 1 showing accommodating portion or cradle of the apparatus in end timber clamping means in side view, the timberview and the Figure 3 is a further view of the apparatus of Figure 1 showing the timber-accommodating portion or cradle in side view and the timber clamping means in end view and in section on the line III-III of Figure 2, Figure 4 is a detail view of the clamping mechanism portion of the apparatus of Figures 1 to 3, showing the clamping mechanism in its over-centre locking disposition, -4Figure 5 is a detail view of the chain-securing end of the transverse channel of the clamping means, showing an alternative arrangement in which the chain is resiliently tensioned by means of a spring, Figure 6 is a side view of an alternative embodiment of the clamping mechanism, Figure 7 is an end view of the alternative clamping mechanism of Figure 6, substantially on the plane VII-VII of Figure 6, and Figure 8 shows an alternative mounting arrangement for the device of the invention.

As shown in Figures 1 to 3 of the accompanying drawings, support apparatus for lengths of timber to be cut into logs of relatively short axial extent consists generally of a timber-accommodating portion or cradle 1 for receiving a number of said lengths of timber, a base portion 2 on which said timber-accommodating portion is mounted, and clamping means 3 for retaining lengths of timber on the timber20 accommodating portion 1.

The timber-accommodating section or cradle 1 is itself defined by respective spaced apart upwardly-opening Vee-shaped sections 4, each of which is in turn defined by two lengths 5 of 40mm angle iron, extending upwardly and outwardly from and welded to the ends of a substantially horizontal length 6 of inverted 40mm angle iron. The spacing between the two Vees is approximately 210mm. A flat bar section 7 closes off the downwardly-directed lower opening of angle iron 6. In the vicinity of the upper or free ends of two of the lengths 5, one in each of the Vee-shaped sections, these lengths 5 being regarded as defining rearwardly-directed arms of the Vee-shaped sections 4, another bar 8 bridges the space between these rear arms 5, for a purpose to be described.

The entire cradle structure or timber-accommodating portion 1 is supported or mounted on a base portion 2 of the apparatus, this consisting of an upright tube 11 of 60mm (outside’ diameter), the upper end of which is welded to the underside of flat bar section 7 and the - 5 lower end of which is mounted on a baseplate 12, which may be, for example, 150mm square and 6mm thick, or which may alternatively, and as shown in Figure 1, be circular. Boltholes 13 are provided in baseplate 12, for enabling the baseplate to be itself fastened in turn to a stabilising concrete base or timber frame.

Alternatively, the base may be a cross-shaped structure formed from 44mm square box iron with arms of approximately lm, a plate being welded to this cross structure for bolting to the foot of the main stand.

Considering now the clamping means of the apparatus, this includes a transverse inverted channel 21 forming the base of the clamping means or structure 3. Transverse channel or member 21 is disposed at an axial spacing from the timber-holding cradle 1 along the length of pillar or tube 11 in the direction of its longitudinal axis and channel 21 also itself has a longitudinal dimension which extends in a direction at right angles to said longitudinal axis. In addition, channel 21 extends substantially at right angles to the direction defined by the inverted angle iron section 6 of the cradle and the flat bar section 7 welded to it. Channel 21 thus extends between a front or operating region of the apparatus and a rear region in which said rearwardly-directed arms 5 of the cradle are bridged by the bar 8.

Chain attachment lugs 22 extend upwardly from the upper flat face of the inverted channel 21 in the vicinity of its rear end. A clamping chain 23 is secured to lugs 22 by a 10mm pin, the pin extending through apertures 24 for receiving the axial ends of the pin and passing through a link of the chain. These and other similar apertures are denoted schematically in Figures 2 to 4, which schematic representation also shows, therefore, the axes of pivoting of the various pins. A small number of the links of the chain are indicated in Figures 2 and 3, but the greater part of the extent of the chain is represented schematically by chain-dotted line 25, (Figure 2), for ease and clarity of interpretation in the drawing.

At the other or forward end of the inverted channel 21, clamping lugs extend upwardly from its upper flat surface. Each of two free links of the locking or clamping mechanism is located on the exterior side - 6 of a respective lug 31. The free links 32 are pivotably mounted on these lugs, a 13mm pivot pin extending through aligned apertures 33 in the lugs and free links respectively. At the upper ends of the free links, the blades of a forked handle link 34 are received between the free links, to which they are pivoted by means of another 13mm pin passing through aligned apertures 35 in the respective ends of the free links and handle link blades. A lever or handle 36 in the form of a rod or tube extends from the closed end of the forked handle link 34, for manual operation in use of the apparatus.

Hook mounting lugs 37 are provided on the handle link and extend laterally from the longitudinal axis of the handle and handle link, so as to enable apertures 38 to be provided at a lateral displacement from said longitudinal axis, said apertures receiving a pivot pin by which a hook member 39 is associated with the remainder of the mechanism. Hook or chain-engaging member 39 engages the other end of the chain from that pivoted to lugs 22, in use of the apparatus.

A stop plate 41, which, along with chain 23, is omitted from Figure 1 for clarity, is mounted between free links 33, and is of a size and orientation such that in an unclamped or open configuration of the clamping means, the hook member 39, when disengaged, will abut against the rear or trailing edge 42 of the stop plate, to limit movement of the hook member, while in a locked or closed configuration of the clamping structure, the handle link 34 abuts against the forward or leading edge 43 of the stop plate. The clamping mechanism is shown in an open and disengaged configuration in Figures 1 and 2, while Figure 4 shows the pivoting portions of it in a closed or clamping disposition. The dimensions and relative locations of the pivoting points in particular are selected so that in the clamping configuration, with handle link 34 abutting stop plate 41, the pivot axis 38 of the hook member relative to the handle link lugs 37 is displaced to the opposite side of the axis extending between the pivot axes 33 and 35 at the opposite ends of the free links as compared with its location in the open condition of the clamping means. In this manner an over-centre clamping or locking mechanism is provided.

Use of the apparatus of the invention is as follows. A bundle of - 7 lengths of timber 61 is placed on the cradle defined by the Vees 4.

The spacing of the Vees 4, while relatively short, is nonetheless sufficient for lengths of timber of up to 3m (10 feet) to be supported with both ends clear of the ground. Thus the longitudinally central portions of the lengths of timber are carried on the Vee-shaped cradle.

The chain 23 is then swung over the timber and a link in the vicinity of its free end is engaged in the hook of member 39, this first of all being swung into the orientation in which its axis extends along the direction denoted by the dashed or broken line 39a in Figure 2. This represents an engaged but unlocked condition of the clamping mechanism, in which the chain is held by the hook, but the handle link lug pivot axis 38 is disposed to the forward or unlocking side of the longitudinal axis of the free links defined between pivot axes 33 and 35 at the opposite ends of these links. Bar 8 facilitates retrieval of the chain for engagement in the hook at this stage, as it prevents the chain from falling to the rear of the unit and away from the cradle region. In engaging the chain onto the hook, the chain is drawn manually over the lengths of timber laid on the cradle, and it is pulled up manually until it is free of any significant amount of slack. The link of the chain which is then closest to the hook 39 is next slipped onto the hook, so that the chain remains relatively taut preparatory to the next stage of the locking or clamping operation.

The timber is then clamped onto the cradle by displacement of the handle 36 from the unlocking or free orientation thereof shown in Figure 2 to the locking or clamping disposition of Figure 4. In this way, the pivot axis 38 of member 39 relative to the handle link is displaced along an arcuate path and into an over-centre position to the rearward side of the axis defined between pivot pin apertures 33 and 35 of the free links, so that the chain is thereby tensioned and locked. The clamping mechanism of the invention provides very powerful and secure retention of lengths of wood on the cradle. The lever-based locking mechanism enables an exceptionally strong gripping force to be exercised, while the irregular exterior profile of the chain means that it digs into the wood and prevents it from slipping, either lengthwise or rotationally, during the cutting stage. The over-centre locking arrangement ensures that the clamping of the wood is positive at all - 8 times during sawing without any effort on the part of the user. Both hands are left free to concentrate on manipulation of the saw, while neither is there any locational constraint on the operator. The user is free to move around to the most convenient sawing position for each cut, and there is no requirement for manual or foot pressure to be applied to the locking mechanism during use of the device.

The clamped wood may then be cut either manually using a handsaw or by means of a chain saw, for example, on the cutting plane designated 62 in Figure 3. A special advantage of the invention is that all cutting operations take place outboard of cradle 1. Thus there is no danger of the saw coming in contact with any of the steel members defining cradle 1. This mode of operation is possible because of the relatively narrow spacing between Vees 4. Nonetheless, the fact that the free ends of lengths of timber supported on the unit are held clear of the ground means that the bending direction of the timber at a cutting plane such as 62 favours the opening-up of the saw cut, thereby avoiding binding of the saw. Also, cut-off material falls away from the remainder of the wood, thus facilitating a speedy rate of working.

Further optional features of the apparatus according to the invention include mounting apertures 44, preferably of 19mm diameter, provided in the transverse channel 31 for further securing the apparatus to a base frame, if required, to give extra stability, or for mounting the unit on an alternative base, to be described. To provide additional resilience in the clamping, when cutting knotty wood in particular, the direct securing of the end of the chain to fixed mounting lugs 22 may be replaced by the arrangement shown in Figure 5. A chain mounting yoke 51 is provided, having an upwardly opening fork within which the chain is received and secured by a pin, as in the case of the static mounting lugs. From the closed lower face of yoke 51, a sliding bolt extends, this passing downwardly and slideably through an aperture in the web of channel 21. Bolt 52 passes through and along the axis of a compression spring 54, denoted schematically only in Figure 5, which is retained between the underside of the web of the channel and a spring plate 55, this being fastened to the free or lower end of bolt 52 by means of a retaining nut 56. Thus the end of the chain is - 9 biassed downwardly by the action of spring 54, and any tendency for the end of the chain to move away from channel 21 is resisted by compression of the spring.

In the alternative clamping mechanism shown in Figures 6 and 7, clamping lugs 71 are provided on channel member 21, similar to lugs 31 of the arrangement previously described. However, in this modified clamping mechanism construction, only a single free link 72 is provided, pivoting on lugs 71 about a pivot pin or pivot axis 73. At the upper end of free link 72, a handle link 74 is provided, defining a forked end to a handle lever 76, similar to the arrangement of Figures 1 and 4, the forked end embracing the upper end of free link 72 and being pivotable relative to it about pivot axis or pin 75. In similar manner to the preceding embodiment, hook mounting lugs 77 again extend downwardly and rearwardly from the free end region of fork portion 74, and hook member 79 is again pivoted to lug portions 77 by means of pivot pin 78. However, in this variant, the hook member is also of divided or forked construction, so that a fork portion 79a of the hook member embraces the outer sides of hook mounting lugs 77. A single operating or hook end region 79b is provided, for engaging the chain, and transition between this operating end and the fork portion takes place clear of free link 72. Stop plate 81 fulfils a similar function to the corresponding plate 41 of the arrangement previously described. This particular variation in the clamping member construction affords certain manufacturing advantages and may be favoured in particular circumstances. Its manner of operation is identical with that already described and an over-centre locking feature is again provided.

An alternative base arrangement is shown in Figure 8. In this instance, the base portion of the arrangement of Figure 1, located below the channel section 21, is absent. Instead, channel 21 is bolted directly to a truck wheel centre 91, by means of bolts 92 passing through the holes 44. The bolts 92 may engage a clamping plate 93 on the underside of the wheel centre 91, or they may engage directly in threaded holes in the wheel centre itself. In use of the device, the wheel centre 91 lies flat on the ground and provides a steady base for the device without it having to be permanently fixed to the ground.

The arrangement is especially advantageous in that the support - 10 apparatus of the invention may be readily moved from place to place, at least over short distances, by tilting the entire unit together with the base 91 until the plane of the wheel is approximately at 45° to the horizontal. The entire unit may then be rolled along on the edge of the wheel rim.

The arrangement represents an especially advantageous and favoured means of mounting the device of the invention.

Claims (8)

1. Support apparatus for lengths of timber to be cut into logs of relatively short axial extent, comprising a timber-accommodating portion for receiving a number of said lengths of timber, a base portion on which said timber-accommodating portion is mounted, and clamping means for retaining lengths of timber on said timberaccommodating portion, wherein said base portion includes at least one pillar means and at least one transverse member, said pillar means having an upper end at which said timber-accommodating portion is mounted, and said transverse member being disposed at an axial spacing from said upper end of the pillar means, having at least one dimension extending in a direction substantially at right angles to the longitudinal axis of said pillar means, and being securable to a stabilising base or frame in use of the apparatus.

2. Support apparatus according to Claim 1, wherein said transverse member is a baseplate.

3. Support apparatus according to Claim 1 or Claim 2, wherein said transverse member has a lower region engageable against an upper region of a circular member, for retention thereagainst by gripping means, so as to enable the apparatus to be moved about by tilting the apparatus and an attached said circular member, for rolling along manually, balanced on the rim or edge portion of the circular member.

4. Support apparatus according to any preceding claim, wherein the clamping means comprises a clamping chain and a locking mechanism, one end of said chain being substantially fixedly associated with a rigid member of the apparatus, and the other end of said chain being engageable by said locking mechanism for retaining the chain in tight engagement with a number of lengths of timber received in said timber-accommodating portion of the apparatus, said locking mechanism including a lever for pivoting displacement relative to said base portion and a chain-engaging member which is mounted for pivoting displacement relative to said lever, said mechanism having a first disposition in which said chain-engaging member thereof may be engaged with or disengaged from a link of the chain and a second disposition in -12which the chain is maintained under tension, the mechanism being displaceable between said first and second dispositions.

5. Support apparatus according to Claim 4, wherein an over-centre 5 locking arrangement is provided in which the mechanism has a further disposition between said first and second dispositions in which the chain is tensioned to a greater degree than when the mechanism is in said second disposition. 10

6. Support apparatus according to any of Claims 1 to 3, wherein the clamping means comprises a clamping chain, one end of which is substantially fixedly associated with a rigid member of the apparatus, and the other end of which may be engaged by a locking means for retaining the chain in tight engagement with a number of lengths of 15 timber received in said timber-accommodating portion of the apparatus, said locking means including a linkage having a first disposition in which a chain-engaging member thereof may be engaged with or disengaged from a link of the chain and a second disposition in which the chain is maintained under tension, the linkage being displacable between said 20 first and second dispositions, and an over-centre locking arrangement being provided in which the linkage has a further disposition between said first and second dispositions in which the chain is tensioned to a greater degree than when the linkage is in said second disposition. 25

7. Support apparatus according to any preceding claim, wherein the timber-accommodating portion of the apparatus consists of a cradle structure defined by spaced apart Vee-shaped sections and at least one further member extending between said sections, said upper end of said pillar means being affixed to said further member of said cradle 30 structure.

8. Support apparatus for lengths of timber to be cut into logs, substantially as described herein with reference to and as shown in the accompanying drawings.