SEALING ARRANGEMENT AND PROCESS FOR ITS PROVISION ON A CHAIN-SAW

Abstract: A sealing arrangement on a chain-saw intended for sawing hard materials such as concrete, preferably a so-called motor-saw comprising a motor driving an enclosed saw-chain arranged to move along the edge of a saw-bar (1) and comprising links (2, 3, 4) of which some are fitted with at least one cutter (5) and some have at least some control lugs (6), arranged substantially in a plane through the saw-bar whereby cuter (5) is orientated away from bar (1) and control lug (6) is orientated inward towards bar (1) while engaging a control (7) which moves along the edge of bar (1) and whereby links (2, 3, 4) are movably joined to one another and entirely or partly enclosed in a seal (12) which follows the saw-chain during its movement along bar (1). Seal (12) preferably abuts the periphery of saw-bar (1) and is provided with edges (13) abutting the respective flat sides of saw-bar (1). The invention also relates to a process for the production of a sealing arrangement whereby a plastic compound is made by pouring to encompass links (2, 3 and 4) entirely or partly and preferably to adhere firmly to the faces of links (2, 3, 4).

Description: SEALING ARRANGEMENT AND PROCESS FOR ITS PROVISION OK A CHAIN-SAW The present invention relates to a chain-saw, preferably a so-called motor-saw, intended for sawing concrete and similar material. However, the invention is not limited to the sawing of concrete but can be applied also when sawing other, preferably hard materials. The chain-saw in accordance--with the invention comprises a motor which drives an enclosed saw-chain arranged along the edge of a saw-bar, comprising links of which at least some are fitted with at least one cutter projecting from the saw-bar. The known motor-saws are provided with a saw-chain consisting of three types of link movably arranged in respect of one another by means of pins in the same way as with known roller-chains. The links consist of saw-links provided with one or several sawteeth respectively, connecting links and control links provided with a drive and control lug engaging a control which moves along the edge of the saw-bar. The saw-links and connecting links are joined in pairs, parallel and OMPI next to one another, by means of pins in such a way that each pair of links consists of a saw-link and a connecting link or two connecting links. Furthermore, the pairs of links are mutually connected by the control-links so as to form a chain. The known saw-chain has the disadvantage that when it is used for sawing hard materials such as e.g. concrete abraded wear-producing material collects in the chain gaps, which causes rapid wear of the chain's gliding surfaces both in the actual chain and within the bar control. Also the drive arrangement fitted to the motor of the saw and driving the chain around the bar is worn owing to the action of the abraded material. The aim of the present invention consists in eliminating these disadvantages. The aim has been achieved by a sealing arrangement for an enclosed saw-chain arranged to move along the edge of a saw-bar and comprising links some of which at least are provided with a cutter and some at least with a control lug, substantially located in a single plane through the saw-bar, whereby the cutter is directed cutwari from the bar and the control lugs are orientated inward towards the bar and engage a control moving along the edge of the bar, with the links being movably joined with one another. The invention is characterised in that the links are entirely or partly enclosed in a seal, with the cutters and the control lugs projecting from the seal. The seal consists of an elastic, strong and wear-resistant plastic which adheres well to the sur aces_of the links and easily penetrate the spaces within the chain during its application, to which end use is mad of its liquid form. The seal is also executed in such a way as to attach to the outer faces of the saw-bar. The invention prevents the abraded wear- roducing material to penetrate to the gliding faces of the saw-chain, as a result of which the life of the chain increases considerably. The invention is described below in respect of an embodiment and with reference to the attached figures. Figure 1 shows an enlarged view of a part of a saw-bar seen from the side, on which a saw-chain moves along its lower edge. Figure 2 shows in a further enlarged form a cross-section in accordance with the line A-A. in figure 1. OMPI The chain-saw in accordance with the example comprises a motor, not shown in the figures, which drives an enclosed saw-chain arranged to move along the edge of a saw-bar 1 , the said chain comprising a series of links consisting of a U-shaped working link 2, the two parallel sides of which are provided with two holes arranged as a pair while at its base a cutter 5 is firmly secured and orientated away from saw-bar 1 , a control link 3 provided with two holes and arranged between the sides of working link 2 on a joint pin 8 so that the other hole of control link 3 is located outside working link 2, a connecting link 4 consisting of two identical link halves provided with two holes each and fitted with the aid of a joint pin i* 1 such a way that there is one link half on either side of control link 3 5 as well .as finally yet one control link 3 fitted with the aid of a joint pin 10 between the two link halves of connecting link 4- Then follows a new link assembly consisting of a working link 2 connected via pin 11 , a control link 3 > a connecting link 4 a a further control link 3- Links 2, 3 a 4 are enclosed in a seal 12 consisting of polyurethane plastic known as adipren, which is applied in a liquid form and during this process penetrates into the spaces within the chain adhering firmly to the link faces. Seal 12 extends downward a little along the short sides of cutter 5 and encompasses the edge of saw-bar 1 by means of overlapping edges 13- The width of seal 12 is identical with the width..of cutter 5 thus making it possible to lower, in the process of sawing, saw-bar 1 into the saw-cut without any damage to seal 12. Cutter 5 consists of a sintered element comprising diamond grain. Cutter is substantially shaped as a rectangular parallelepiped, one wall of which consists of part of a cylindrical surface. Cutter 5 is attached to working link 2 with the cylindrical surface arranged at right angles towards the plane through the saw-bar, as a result of which the cutting edge of cutter 5 is given an obtuse angle, which reduces the danger of damage especially when sawing with the end of saw-bar 1 where the saw-chain is bent around the end of the latter so that the angle of attack of cutter 5 in respect of the material to be worked upon becomes unfavourable. Cutter 5 is attached to working link 2 by means of a hard-brazed area 14 at its U-shaped base. With alternative embodiments of the chain-saw in accordance with the invention the connecting links 4 can be replaced by a working link - It is also possible to make use of links, not shown in the figures, without control lugs 6 instead of e. g. every other control link 3- Alternatively, working link 5 can be provided with a seat, not shown in the figures, for cutter 5j thus enabling higher loadings. OMPI

Claims: PATENT CLAIMS 1. A sealing arrangement on a chain-saw intended for sawing hard materials such as concrete, preferably a so-called motor-saw comprising a motor driving an enclosed saw-chain arranged to move along the edge of a saw-bar (l), comprising links (2, 3 ? 4) of which some at least are provided with a cutter (5) and some at least with a control lug (β) arranged substantially in a plane through the saw- bar whereby the cutter (5) is orientated away from bar (l) and control lug (6) is orientated inward towards bar (l) while engaging a control (7) which moves along the edge of bar (1 ) and whereby the links (2, 3-* 4) are movably joined to one another, c h a r a c t e r i s e d in thatlinks (2, 3» 4) are entirely or partly enclosed in a seal (12) which follows the saw-chain during its movement along bar (1). 2. A sealing arrangement in accordance with claim 1 , c h a r a c t e r i s e d in that seal (12) abuts the periphery of saw-bar (1 ). 3- A sealing arrangement in accordance with claim 2, c h a r a c t e r i s e d in that seal (12) is provided with edges (13) which abut the respective flat sides of saw-bar (1). 4. A process for producing a sealing arrangement on a chain-saw with a saw-chain comprising links (2, 3 3 4) c h a r a c t e r i s e d in that a plastic compound is made by pouring to encompass links (2, 3, 4) entirely or partly. 5. A process in accordance with claim 4 c h a r a c t e r i s e in that the plastic compound is caused to adhere firmly to the faces of links (2, 3, 4). OMPI WIPO

Inventors: GUSTAVSSON OVE, GUSTAVSSON, OVE
Applicants: GUSTAVSSON OVE, GUSTAVSSON, OVE
Application year: 1983
Main classification: B28D1
IPC codes: B28D1