~ his invention relates to saw guide systems and more particularly to an improved saw blade lubricating guide and apparatus for circular gang saws.
Saw blades, especially of circular'saws, very often have to be guided due to their running and operating conditions as well as to maintain the required sawing accuracy. If a sufficiently thick material is used for the saw blade, internal tension, caused by tem-perature differences along the radius, may not lead to bending of the blade. However, it is well known that sawing with thinner blades and thinner kerfs is more efficient and cost effective.
Accordingly, to maintain sawing accuracy and to avoid saw blade bending, as well as vibration of the blade, the blade has to be guided. A guided blade will reduce the amount of sawdust, improve the sawing accuracy and minimize the amount of power needed to rotate the blade. In machines using several guided SAW blades, these guides are lubricated by oil and/or water, someti-mes mixed with air. In these prior systems the lubricant and/or water is fed through a single conduit and distri-buted uncontrolled to the guides. The lubricating fluid has been found to slip through the widest available gaps thereby starving smaller gaps which actually need the '1 ~
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greatest amount of lubrication especially if the blade i8 pressed by the wood against the guide. When this occurs a certain amount of unnecessary wear takes place at the guide.
~ ormally there is wear material attached to guides to avoid wear of the saw blade. A bearing-babbit-material i8 most often used as wear mater;alO
Accordingly, when the blade is pressed against a guide, the babbit has to be replaced. This results in unne-cessary down-time of the machine and accordingly increases the operating costs. In additionJ if wear does take place, a loss in sawing accuracy arises since the saw blade no longer rests in the adjusted position.
Because of the friction of metal to metal, in addition to the fluid friction, the temperature in the blade increases and hence the input power has to be increased in order to override the unnecessary friction. Also, the uncontrolled temperature differences along the blade radius will increase the saw blade bending and vibration.
The applicant has found that these disadvan-tages may be overcome by providing a compulsory fluid feeding system with anti-wear and heat-resistant liner attached to the guide and a simple temperature control system.
It is therefore an object of the present inven-tion to provide an improved saw blade lubricating guide -; ,, : ~ : : -:
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Another object of the present invention is to provide an improved saw blade lubricating guide in which a flow divider is provided in each guide in order to per-mit lubricant to reach the surfaces of the guide which are held adjacent the saw blade.
Yet another object of the present invention is to provide an improved saw blade lubricating guide which is provided with anti-wear and heat-resistant liner.
In yet another object of the present invention is to provide an improved saw blade lubricating and guiding apparatus for circular saws and which the tem-perature of each blade is controlled and monitored so that lubricant flow can be increased if the temperature of the blades increases.
Accordingly, it is an aspect of the present invention to provide an improved saw blade lubricating guide for circular gang saws, wherein said saw blade guide is mounted on a support, before said saw blade, said guide having lubricant supply and distribution means, said lubricant being fed directly to said saw blade guide by conduit means, said lubricant distribution means being located on surfaces of said guide which is held adjacent the saw blade.
According to another aspect of the present ' "~ '-~. :: ~ : ' ~7~7~
invention, there is provided a saw blade lubricating and guiding apparatus for circular saws, comprising: a saw blade guide mounted on a support, before said saw blade, having lubricant supply and distribution means, said lubricant being fed directly to said saw blade guide by conduit means, said lubricant distribution means being located on surfaces of said guide held adjacent a saw blade; manifold means for distributing lubricant to each of said conduit means; :flow regulator means connected to said manifold means; temperature sensor means for sensing temperature change in said blades, said tem-perature sensor means being connected to said flow regu-lator means via transformer and amplifier means such that if the temperature of said saw blade increases said regu-lator means will increase flow of lubricant through said conduit means to said guides.
Particular embodiments of the invention will be understood in conjunction with the accompanying drawings in which:
Figure 1 is an illustrative schematic of the saw blade lubricating and guiding apparatus according to an aspect of the present invention;
Figure 2 is an isometric view of the improved saw blade lubricating guide according to a second aspect of the present invention; and Figure 3 is a partially sectioned side view of .. :.: .: . -,,, . . - ::
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the improved saw blade lubricating guide shown in Figure 2.
If we now refer to Figure I we have shown at reference numeral 10 a partially sectioned isometric view of a circular gang saw machine having housing 11 a number of circular saws 12 supported on a shaft 13 which can be connected to driving means (not shown).
Saw blades 12 are guided by a series of saw blade guides 14. Although other configurations can be used, in the present embodiment a pair of adjacent saw guides are used for guiding each individual saw blade.
Guides 14 are supported on a hollow shaft 15 which houses a number of lubricant conduits 16. Each guide is separa-tely connected to its own lubrieant conduit such that lubricant is continuously fed to each individual saw guide.
A -air of manifolds 17 ensures continuous flow of lubricant through eaeh individual conduit. Each mani- -fold is fed lubricant by means of flow regulators 18 which are connected to lubricant supply lines 19. The flow regulators are adjusted by means of a control cir-cuit 20 which includes a signal amplifier 21 connected to each flow regulator 18 and a signal transformer 22 con-nected to amplifiers 21 and a temperature transducer 23 whieh will produce a signal proportional to the tem-perature of the saw blades 12. In the present embodi-: . ~'''' : ' ,: , ' ,:: :
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ment, transducer 23 consists of an infra-red sensor which will monitor any temperature change of the saw blades 12.
Infra-red transducer 23 has been adjusted to be sensitive to a temperature change within a specified range depicted by an angle alpha. A number of sensors could also be used to permit the monitoring of each blade and hence permit individual temperature control for each blade.
This non-contact temperature sensing arrange-ment is preferred since any existing saw dust will not influence its measurements. In operation, transducer 23 will produce a voltage indicative of a temperature increase. Transformer 22 will increase or decrease this voltage according to input voltage requirements of the amplifiers 21. A signal will then be received by flow regulators 18 to increase the amount of fluid flow through conduits 16 such that each saw blade guide will be supplied with additional fluid to increase the cooling effect to each saw blade.
Referring now to Figure 2 we have shown an iso-metric view of a single saw blade guide 14 fixedly mounted to hollow support shaft lS. Except for the guides located at each end of the support shaft 15, each guide is provided with a liner 30 located on each side of the guide. Liners 30 are secured to mounting plate 31 forming the rear end of guide 14 which is integrally con-nected to a securing jaw 32 which allows the guide to be .
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mounted on support shaft 15. Liner 30 is made of an anti-wear heat-resistant material such as ceramic. The use of ceramic as wear material will help reduce fluid friction and help maintain a reasonable temperature of the blade. The invented C-shape of liner 30 helps reduce the friction that would otherwise exist with a full plate liner. A 30% of friction reduction will be possible.
Each liner is provided with a pair of channels 33 or Eluid supply gates which extend along the sides of liner 30. The decreasing width of channels 33 help create a coriolis effect along liner 30 to promote the flow of lubricant right across the full area of the liner. This formation helps create a full hydrodynamic lubricant film along the liner thereby increasing effective cooling of the saw blade. Lubricant is supplied to channels 33 by means of a flow divider 34 which is connected by means of internal tube 35 to a first supply conduit 36 and a second supply conduit 24. The connecting arrangement is more clearly shown in Figure 3. By providing each guide with its own fluid conduit and fluid divider, lubricant can reach each individual guide and permit an effective lubrication at liners 30 on each side of the guide.
Referring now to Figure 3 we have shown a par-tially sectioned side-view of the saw blade guide 14 shown in Figure 2. Guide support shaft 15 is provided with aperture 40 through which the distal end of lubri-cant conduit 24 is inserted. Fluid will pass throughconduit 24 into inclined tube 41 to reach tube 35 via a tapered tubular section 42. Fluid from conduit 24 can be mixed with air and/or water injected through flow divider 36. An elastomeric seal 43 is provided between shaft 15 and guide 14. This seal will permit guide 14 to be rotated to the position shown by phantom lines and removed without having to disconnect any conduit or supply lines. It is necessary to remove the guides in order to have easy acess to the saw blades when main-tenance or replacement is required. The distance between upper lip 44 and lower lip 45 of jaw 32 is such as to permit the removal of guide 14 when lips 44 and 45 become aligned with the flat machined sections 46 and 47 respec-tively of support shaft 15. Stop 48 is used as a pivot preventor to keep the guide 14 in the horizontal posi~
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