FR2521057A1 - CHAIN GUIDE FOR A CHAIN SAW - Google Patents

Abstract

The invention relates to a chain guide for a chain saw, with a pair of side plates, between which a spindle is arranged in a fixed position, and a chain wheel which is rotatably mounted relative to the spindle. The chain wheel is rotatable about the spindle and serves to direct the saw chain, moving at high speed, around the edge of the guide. Roller bearings are arranged between the spindle and the chain wheel. A pair of annular seals are in each case arranged between the chain wheel and one of the side plates and between the chain wheel and the other side plate. Each of the seals has an annular bead which rebounds at an angle and is in flexible contact with a surface of the chain wheel or one of the side plates. If no lubricant is supplied, a lubricating opening formed in each side plate is closed by a flap on an annular seal or an elastic valve device which is inserted into a central bore of the spindle. When lubricant is supplied under pressure via the opening, the flap or the valve device yields on account of the elasticity and enables the roller bearings to be supplied with grease.

Description

 CHAIN GUIDE FOR A CHAIN SAW.

 The present invention relates to a chain guide for a chain saw.

In the known field, a chain saw guide usually supports at one end a rotating pinion to guide a saw chain, so as to allow its rapid movement around the edge of the guide. The pinion axis is periodically greased through an access hole in the lateral flanges of the guide. Since the pinion is subjected to high temperatures while it is rotated by the rapid movement of the chain, the grease on this axis is liquefied under the effect of the intensive heating produced and it follows that the grease leaks and after a short time the pinion turns without lubricant and therefore seizes on its axis. Consequently, in known embodiments,
frequent lubrication is necessary for safe operation after an extended period of service. In addition, foreign matter such as saw dust, dirt or water, often penetrate through the gaps between the pinion and the side flanges of the guide and tend to mix with the grease on the axis. Then, the axis, the pinion and the roller bearings arranged between them malfunction, and this results in damage attributable to the incorporation of materials foreign to said lubricant.

According to the present invention, two annular elastic seals are placed respectively on each side of a chain sprocket
sawing and are interposed respectively between the pinion and one of the lateral flanges of the guide, and between the pinion and the other lateral flange, the pinion being rotatably supported between the lateral flanges of the guide.

The seals prevent the lubricant from leaking from the bearings, and they also prevent the penetration of foreign matter into the
bearings, which would otherwise occur through the intervals between the pinion and the side plates. We can foresee, in
pinion axis, a valve used to normally close the lubricant supply port to prevent lubricant leakage and penetration
foreign matter through said orifice.

 The object of the invention is to provide a chain saw guide comprising means for hermetically isolating the pinion bearing placed in the guide against penetration of saw dust, dirt, dirt, rain water and other foreign matter and also to prevent leakage of lubricating grease from said pinion.

 Another object of the invention is to produce a chain saw guide comprising a pinion bearing which is lubricated at all times with a desired quantity of grease without the need for frequent lubrication.

 Another object of the invention is to provide a chain saw guide comprising a pinion, the roller bearings of which are free from jamming and jamming attributable to the presence of foreign materials.

 The invention further aims to provide a chain saw guide whose service life is extended.

 Other objects and advantages of the present invention will appear on reading the following description and the appended figures, given by way of illustration but not imitative.

 Figure 1 is a front view, partially broken away, of a chain saw guide according to a first embodiment of the present invention.

 Figure 2 is a sectional view taken on the line II-II of FIG. 1.

 Figure 3 is a fragmentary perspective view of a seal used in the guide of Figure 2.

Figure 4 is a sectional view, similar to Figure 2 and showing a chain saw guide according to a second embodiment of the invention
Figure 5 is a fragmentary perspective view of a gasket used in the guide of Figure 4.

 Figure 6 is a sectional view of a third embodiment of the chain saw guide according to the invention.

 FIG. 7 is a fragmentary perspective view of a seal intervening in the guide of FIG. 6.

 Figure 8 is a sectional view of a fourth embodiment of a chain saw guide according to the invention.

 Figure 9 is a perspective view of a fixed axis used in the guide of Figure 8.

 Figure 10 is a sectional view of a fifth embodiment of a chain saw guide according to the invention.

 Figure 11 is a perspective view of a fixed axis involved in the guide of Figure 10.

Figure 12 is a sectional view of a sixth embodiment of a chain saw guide according to the invention;
Figures 13 and 14 are fragmentary perspective views of other seals, in accordance with the present invention.

Figure 15 is a front view, partially broken away, of another embodiment of the invention; and
Figure 16 is a section taken along line III-III of Figure 15.

 In Figures 1 to 3, there is shown a chain saw guide which comprises two lateral flanges 2, 2 spaced from one another by a spacer 14 and supporting between them a rotating pinion 3 placed at one end of the guide 1. The lateral flanges 2, 2 have in their opposite interior surfaces two respective annular grooves 5, 5 which are concentric with the pinion 3 and which have a diameter greater than that of a central bore 4 of the pinion 3. The lateral flanges 2, 2 comprise several counterbored holes 8 which are placed radially inside the annular grooves 5, 5, said holes 8 being respectively aligned with several holes 7 for passing rivets which are formed axially in an axis 6 mounted in the bore central 4 of the pinion 3 and interposed between the lateral flanges 2, 2. The lateral flanges 2, 2 also have two access openings 9, 9 which are placed radially inwards relative to the annular grooves 5, 5 and which s have adjacent to the periphery of the central bore 4.

 An annular seal 11, formed of an elastic material such as an oil-resistant rubber, a plastic material or a felt, is housed in each of the annular grooves 5, 5, this annular seal 11 comprising a wall bottom coming to bear in the groove 5 and a lip 10 extending radially outward from the bottom wall and at a certain angle relative to a plane parallel to the surface of this bottom wall. The inclined lip 10 projects axially from the inner surface of the lateral flange 2 so as to come into contact with the corresponding surface of the pinion 3. The seal 11 is glued or otherwise fixed to the annular groove 5. A number of rollers 12 are arranged between the axis 6 and the pinion 3 so as to be able to rotate around said axis 6. The axis 6 is placed in a fixed position between the lateral flanges 2, 2 while being held in place by several rivets 13 engagesin the holes 8 formed in the lateral flanges 2, 2 and in the holes 7 formed in the axis 6, the ends of the rivets 13 being fixed on the lateral flanges 2, 2. Consequently, the pinion 3 can rotate around the axis 6 by means of the rollers 12 so as to guide a saw chain (not shown) in order to allow its rapid movement around the peripheral edge of the guide 1.

 The lubricant or grease is introduced via the access holes 9, 9 into the roller bearing 12. The lips 10, 10 of the annular seals 11, 11 are held elastically in sliding contact with the surfaces of the pinion 3 to at all times, namely both when it is at rest and when it is rotating at high speed. The fat is therefore prevented by the lips 10, 10 from leaking radially outwards along the faces of the pinion 3. In addition, the lips 10 prevent saw dust, grime, stains, rainwater or other foreign matter to penetrate through the gaps or clearances between the pinion 3 and the side flanges 2, 2.

Figures 4 and 5 show a second embodiment of a chain saw guide blade according to the invention, this embodiment being essentially identical to the guide blade shown in Figures I to 3 except that two annular seals 22, 22 are provided. Each of the annular seals 22, 22 is mounted in an annular groove 16 formed in the inner surface of one of two lateral flanges 15, 15 and it has an outer peripheral lip 17 projecting obliquely from a bottom wall and facing outward from the groove 16 so as to abut elastically against a corresponding surface of a pinion 19. The seal 22 also includes an annular flange 18 projecting axially and disposed radially inward of the lip 17, being oriented at a right angle, as shown in the Figure, or obliquely to the bottom wall in order to abut elastically against e the gable surface. A tongue-shaped element 20 playing the roll of a valve is directed radially inwards from the seal itself, and it is normally kept applied against the surface
inside of the pinion 19 to cover a lubricant supply orifice 21. The seal 22 also includes several small protrusions 23 of circular cross section which start from the bottom wall of the seal 22 in a direction opposite to the flange 18.

The protrusions 23 are respectively engaged in several small holes or notches 24 formed in the lateral flange 15 in the region of the annular groove 16 so that the seal 22 is blocked without being able to move relative to the lateral flange 15-even during a rotation at high speed of the pinion 19. When the grease is discharged via the access orifices 21, the valve 20 is spaced apart from the lateral flange 15, allowing the grease to arrive on the rollers 25 of the roller bearing.

 In accordance with the third embodiment shown in Figures 6 and 7, a chain sprocket 26 has on its opposite surfaces two relatively shallow annular grooves 27, 27 which are concentric with the sprocket 26 and which are directed towards the opposite inner surfaces of two lateral flanges 31, 31 of a chain saw guide. An annular seal 28 is housed in each of the annular grooves 27, 27 and it comprises an outer peripheral lip 29 projecting obliquely from the annular groove 27 and kept applied elastically against the corresponding interior surface of the lateral flange 31. pressurized grease introduced via an orifice 32 causes the valve 33. to elastically move away from said orifice to allow the grease to access the roller bearing 34.

 As shown in Figure 8, a chain saw guide arranged in accordance with the present invention has two lubrication holes 41, 41 which are provided in two side flanges 43, 43 and which are arranged concentrically with respect to a pinion 38 or by relative to an axis 39 provided with a central hole 40. Two seals 35, 35 are essentially identical to the seals 22, 22 of FIGS. 4 and 5, except that each seal 35 does not have any flap valve to close normally l lubrication hole.

Each of the seals 35, 35 comprises an outer peripheral lip 36 and a flange 37 directed radially inwards and held elastically applied against the corresponding surface of the pinion 38 to prevent leakage of grease and the introduction of foreign matter. A cup-shaped valve 47 of circular cross section is disposed in the central hole 40 of the axis 39, this valve 47 being formed of an elastic material such as oil-resistant rubber, plastic or felt.

The bowl-shaped valve 47 comprises an annular end 42 held in contact with the interior surface of one of the lateral flanges 43, 43 surrounding the orifice 41, an exterior peripheral surface 44 maintained, applied against the interior peripheral surface delimiting the central hole 40 of axis 39, and a closed bottom surface 45 which is held pressed against the interior surface of the other lateral flange 43. The bottom surface 45 has a small axial projection 46 of circular cross section which normally penetrates in the orifice 41 of the other lateral flange 43 to seal it. When grease is introduced under pressure into the orifice 41 normally closed by the projection 46 the bottom surface of the valve 47 is pushed elastically while being moved apart from the inner surface of the lateral flange 43, so that the projection 46 is moved backwards with respect to its position for closing the orifice. which allows the grease to be introduced, via the orifice 41, and to flow on the bottom surface of the valve 47. In one of its axial ends, the axis 39 is provided with several radial notches 48 (Figure 9) spaced angularly or circumferentially from one another. The grease feeds the roller bearing 49, the rollers of which are distributed around the axis 39, flowing thereon via the notches 48. With such an arrangement, the grease can be introduced only by one of the orifices 41, 41 because the other orifice 41 is surrounded by the annular end 42 of the valve 47 on which grease cannot flow.

 Figure 10 shows a fifth embodiment of the chair saw guide according to the invention, which is equipped with two cup-shaped flaps 51, 51. The structure and function of the two annular seals 52, 52 are the same as that described for the seals 35, 35 in Figure 8 and, therefore, no further description is necessary. The valves 51, 51 are formed from an elastic material such as oil-resistant rubber, plastic or felt, and they are placed facing each other in a central hole 59 of an axis 50, annular edges or axial interior surfaces 58, 58 valves 51, 51 being kept applied one against the other.

Each of the valves 51, 51 has a radially outer peripheral surface 60 which is kept in contact with the inner peripheral surface delimiting the central hole 59 of the axis 50, an axial or bottom outer surface 61 held against the inner surface of the one of two lateral flanges 5b, 5b and a small axial projection 62 of circular cross section which is provided in the center of the bottom surface 61 to close one of two grease supply orifices 57, 57 formed in the lateral flanges 56, 56. The axis 50 comprises, in each of its axial extremi-ties, several radial notches 63 (Figure 11) which allow grease to flow on the axis 50 towards the roller bearing 64 including the rollers are distributed around said axis 50.

 In accordance with this fifth embodiment, one or other of the valves 51, 51 can deviate under the effect of the pressure exerted by the grease and, consequently, the grease can pass through one or the other. other of the orifices 57, 57.

 According to a sixth embodiment shown in FIG. 12, a valve mechanism mounted in a central hole 70 of an axis 69 comprises two spaced discs 71, 71, which are formed from a metal or a plastic, and an annular element 72 in the form of rubber, for example an O-ring interposed between the discs 71, 71. The discs 71, 71 are normally kept in contact with the interior surfaces of two lateral flanges 73, 73 to close two lubrication orifices 74, 74 households respectively in the lateral flanges 73,73 thereby preventing a leakage of grease and penetration of dust, water, etc. through the openings 74, 74. Of the grease supplied under pressure through from one of the orifices 74 pushes the corresponding disc 71, the rubber ring 72 being elastically compressed, and it is introduced by means of the notches 75 in the axis 69 so as to reach the roller bearing 76 via orifice 74. Two annular seals 65, 65 are provided and they have a structure and a function which are identical to those of the seals 35, 35 of FIG. 8.

 Other forms of seals can also be used.

For example, an annular seal 77 having a V-shaped cross section, known as shown in FIG. 13, or an annular seal 78 having a half cross section, can be used in a chain saw guide according to the present invention. circular. In addition, the gears shown and described can be replaced by rotating discs.

The embodiment of Figures 15 and 16 corresponds to the mode of
Figure 8 described above before its shape is changed. Lubrication orifices 80, 80 which are respectively provided in the lateral flanges 81, the axis 84 carrying a pinion 82, and the central bore 83, are arranged concentrically. On one side of the lateral flange 81, several notches 85 are provided opposite the axial end of the axis 84. These notches 85 constitute grease supply passages of a roller bearing 86 whose rollers are distributed around the circumference of the axis 84 so that the grease introduced into the central bore 83 of the axis 84 reaches the rollers of the bearing 86 via the notches 85. These notches 85 are hollowed out or press formed in the inner surface of the lateral flange 81. The valve 87, which is identical to the valve 47 of FIG. 8, is inserted in the central bore 83. Outside the roller bearing 86, seals 88, 88 are provided which are identical at the seals 35, 35 of Figure 8, so that they prevent the release of grease.

 Of course, the invention is not limited to the embodiments described above, which can be the subject of numerous variants and can be combined with one another.

Claims (8)

 1.- Chafne guide for a chain saw, characterized in that it comprises  - two lateral flanges (2) spaced axially;  - A pinion (3) of saw chain supported in rotation between said lateral flanges and having a central bore (4) passing through it axially;  - an axis (6) disposed in the central bore so as to allow the rotation of said pinion around it;  - the sides of said lateral flanges (2) which are turned towards each other respectively comprising an annular groove (5), said annular grooves being concentric with said central bore (4) and having a diameter greater than this;  each of said lateral flanges having a hole (9) passing therethrough and placed radially outside the radial outer periphery of said axis and radially inside said annular groove to supply lubricant to said guide guide;  - And two elastic annular seals in the form of a cup (11) which are each respectively arranged in one of the annular grooves and which comprise an annular lip (10) inclined and extending radially outwards so as to come into tight contact and sliding with the corresponding surface of said pinion (3) in order to maintain lubricant inside said guide bar.  2.- Chain guide for a chain saw, characterized in that it comprises:  - two lateral flanges (15) spaced axially;  - A sprocket (19) of saw chain supported in rotation between said lateral flanges and having a central bore passing axially therethrough;  - an axis (6) disposed in the central bore so as to allow the rotation of said pinion (19) around it;  - the sides of said pinion (19) which are respectively turned towards said lateral flanges (15) each comprising an annular groove (16), said annular grooves being concentric with said central bore and having a diameter greater than this;  each of said lateral flanges (15) having an orifice (21) passing through it and placed radially outside the radial outer periphery of said axis (6) and radially inside said annular groove (16) to supply lubricant said chain guide;  - And two elastic cup-shaped annular seals (22) which are each respectively arranged in one of the annular grooves (16) and which have an annular lip (17) inclined and extending radially outwards so as to enter into leaktight and sliding contact with the curved-undulating lateral surface of the pinion (19) in order to maintain lubricant inside said chain guide.  3.- Chain guide for a chain saw, characterized in that it comprises;  - two lateral flanges (31) spaced axially;  - A sprocket (26) of saw chain supported in rotation between said lateral flanges and having a central bore passing axially therethrough;  - an axis (6) disposed in the central bore so as to allow the rotation of said pinion (26) around it;  - the sides of said lateral flanges (31) which are turned towards each other respectively comprising an annular groove (27), said annular grooves being concentric with said central bore and having a diameter greater than this;  - Each of said lateral flanges (31) being provided with an orifice (32) is placed radially inside the periphery of said central bore and which communicates with this central bore to supply lubricant to said chain guide;  - And two elastic cup-shaped annular seals (28) which are each respectively arranged in one of the annular grooves (27) and which have an annular lip (29) inclined and extending radially outwards so as to enter into tight and sliding contact with the corresponding surface of the flanges (31) in order to maintain lubricant inside said guide bar.  4.- Chain guide for a chain saw, characterized in that it includes:  - two lateral flanges (43) spaced axially;  - A pinion (38) of saw chain supported in rotation between said lateral flanges and comprising a central bore (40) passing axially through it;  - an axis (39) disposed in the central bore (40) so as to allow the rotation of said pinion (38) around it;  - Each of said lateral flanges (43) being traversed by an orifice (41 placed radially inside the periphery of said central bore and communicating with said central bore (40) to supply lubricant to said chain guide;  - two elastic annular seals (35), which respectively have a diameter greater than that of the central bore (40) and which are respectively placed between one side of one of said lateral flanges (43) and one side of said pinion (38), being respectively aligned concentrically with said pinion to maintain lubricant in said chain guide;  - And a cup-shaped elastic valve (47) placed in a fixed position in said central bore (40) and comprising a bottom surface (45) abutting against one side of one of said lateral flanges (43), said surface bottom (45) being provided with an axial projection (46) which penetrates into and closes one of the desoriftces (41) in order to maintain lubricant in said guide bar and, when lubricant under pressure is introduced into the one of the holes for bending axially inwards towards said axis (39) and for opening one of the holes (41) in order to admit lubricant into said chain guide.  5.- Guide-chalne for a chain saw, characterized in that it includes:  - two lateral flanges (56) spaced axially;  - A saw chain sprocket rotatably supported between said lateral flanges and comprising a central bore (59) passing through it axially;  - an axis (50) disposed in the central bore (59) so as to allow the rotation of said pinion around it;  - Each of said lateral flanges (56) being traversed by an orifice (57) placed radially 1 "inside the periphery of said central bore and communicating with said central bore (59) to supply lubricant to said guide bar;  - two elastic annular seals (52), which respectively have a diameter greater than that of the central bore and which are respectively placed between a side of said lateral flanges (56) and a side of said pinion, being respectively aligned concentrically with said pinion to maintain lubricant in said guide bar;  - And two cup-shaped flap valves (51), placed in opposite positions inside said central bore, each of said valves respectively comprising an axial internal surface (58), said internal surfaces (58) abutting the one against the other for placing said valves (51) in a fixed position, each of said valves (51) respectively comprising an axial external surface (61), said external surfaces (61) abutting respectively against one side of one of said flanges lateral (56) and ensuring the closing of one of the holes (57) to maintain lubricant in said guide bar and, when pressurized lubricant is introduced into one of the holes (57), to bend axially inward towards said axis (50) to open one of the holes (57) for the admission of lubricant into said guidemechanism.  6.- Chain guide for a chain saw, characterized in that it comprises  - two lateral flanges (73) spaced axially;  - A saw chain sprocket rotatably supported between said lateral flanges and having a central bore passing axially therethrough;  - an axis (69) disposed in the central bore so as to allow the rotation of said pinion around it;  - Each of said lateral flanges (73) being traversed by an orifice (placed radially inside the periphery of said central bore and communicating with said central bore to supply lubricant to said chain guide;  - two elastic annular seals (65), which respectively have a diameter greater than that of the central bore and which are respectively placed between one side of one of said lateral flanges (73) and one side of said pinion, being respectively aligned concentrically with said pinion to maintain lubricant in said guide bar;  - And a valve positioned in said central bore, said valve comprising an elastic annular element (72) and two disc-shaped elements (71), each of said disc-shaped elements (71) abutting respectively against a side of a of said lateral flanges (73) and ensuring the closing of one of the orifices (74) for holding lubricant inside said chain guide, said annular element (72) being positioned axially between said disc-shaped elements (71 ) and coming to abut against them to position them for closing the orifices (74) and, when pressurized lubricant is introduced into one of the orifices (74) and against one of said disc-shaped elements, to exert a compression directed axially inwardly to allow lubricant under pressure to move one of said disc-shaped elements (71) to thereby admit lubricant into said guide bar.  7.- Chain guide for a chain saw, characterized in that it comprises:  - two lateral flanges (15) axially spaces;  - a pinion (19) of saw chain supported in rotation between said lateral flanges (15) and comprising a central bore passing axially therethrough;  - an axis (6) disposed in the central bore so as to allow the rotation of said pinion (19) around it;  the sides of said lateral flanges (15) which are directed one verso'autour each comprising respectively an annular groove (16) and several notches (2 the annular grooves being concentric with said central bore and having a diameter greater than this, the notches (24) of each lateral flange communicating respectively with the corresponding annular groove and extending axially with respect thereto;  - Each of said lateral flanges being traversed by an orifice (21) placed radially outside the radial outer periphery of said axis (6) and radially inside said annular groove (16) to supply lubricant to said guide bar ; ;  - two annular elastic seals (22) each of which is respectively positioned in one of said annular grooves (16) to come into tight and sliding contact with the corresponding surface of said pinion (19) in order to. maintaining lubricant in said guide bar; and  - Each of said seals (22) comprising several projections (23) which each engage respectively in one of said notches (24) in order to ensure the fixing of the corresponding seal (22) on the corresponding side flange (15).  8.- Chain guide according to claim 4 or 5, characterized in that the axial outer surfaces of said axis (39.50) have several notches (48,63) extending radially from its central bore (40,59) up 'at its outer periphery for supplying lubricant to said pinion (38).