Oil supply structure of chain saw

An oil supply structure of a chain saw comprises a pair of rail portions which are provided on the outer circumference of the main body of a guide plate, a guide groove which is formed between the two rail portions, a pair of oil supply holes which penetrate the two rail portions from outside and which open toward the guide groove, a through hole which penetrates the main body of the guide plate without any connection with the guide groove, and a pair of connection channels which connect outer end openings of each oil supply hole and two outer end openings of the through hole. Lubricating oil is supplied from an outlet port of the main body of the chain saw to both sides of a saw chain and so forth through the through hole, connection channel and oil supply hole.

FIELD OF THE INVENTION 
This invention relates to a structure for oiling a chain saw, and more 
particularly to a structure for oiling a guide plate or saw chain and the 
like of a chain saw. 
DESCRIPTION OF THE RELATED ART 
A structure for oiling a saw chain of a chain saw in which, as shown in 
FIGS. 22(a) to 24, a guide plate 131 is provided with an oil supply port 
132 is known. That is, the oil supply port 132 shown in FIGS. 22(a) and 
22(b) is formed in such a manner that it penetrates both rails 134 of the 
guide plate 131 so as to communicate with a guide groove 133 formed in the 
guide plate 131. The oil supply port 132 shown in FIG. 23, penetrates one 
of the rail portions 134 at an angle, and the inner end thereof 
communicates with one side surface of the guide groove 133. The oil supply 
port 132 shown in FIG. 24 is formed by an oblong groove 135 which extends 
in the direction of the width (vertical direction) on the outer side 
surface of one rail portion 134 of the guide plate 131 and a through a 
hole 136 which is formed in such a manner that the hole opens toward the 
guide groove 133 from one end of the oblong groove 135. 
Oil is forced by pressure from the main body of the chain saw in the 
direction indicated by the arrow (FIG. 24) and into the guide groove 133 
through the oil supply port 132. 
As shown in FIGS. 23 and 24, oil is supplied to only one side of the guide 
groove 133 of the guide plate 131. The oil therefore can be supplied to 
the portion between the inside of the rail portion 134 adjacent to the oil 
supply port 132 and a drive link 138 of a saw chain 137, and the portion 
between the outer circumference of the rail portion 134 adjacent to the 
oil supply port 132 and a side link 139 of the saw chain 137. However, oil 
can not be sufficiently supplied to the other portions, that is, the 
portion between the inner surface of the rail portion 134 opposite to the 
oil supply port 132 and the drive link 138 of the saw chain 137, and the 
portion between the outer circumference of the rail portion 134 opposite 
the oil supply port 132 and the side link 139 of the saw chain 137. 
Furthermore, in the guide plate 131 in the related art, as shown in FIGS. 
22(a) and 22(b), oil is intended to be supplied to the guide groove 133 
from two sides thereof, but actually the oil is scooped up by the drive 
link 138 of the saw chain 137 as soon as it enters in the guide groove 
133, so that the opposite side of the entrance is not sufficiently 
supplied with oil. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide an oil supplying structure 
for a chain saw which is capable of sufficiently supplying oil to the 
portion between the outer circumference of two rails of a main body of 
guide plate and a side link, between inner surfaces of a guide groove and 
two outer side surfaces of a drive link and the portion which connects the 
drive link and side link of a saw chain. 
Another object of the peresent invention is to provide an oil supplying 
structure in which a through hole thereof is never choked with wood chips. 
A further object of the present invention is to provide an oil supplying 
structure for a chain saw which is capable of sufficiently supplying oil 
to the portion between the inner surface of a rail portion which is 
located opposite to an outlet port and a drive link of a saw chain, 
between the outer circumference of the rail portion opposite to the outlet 
port and a side link of the saw chain and the portion which connects the 
drive link and the side link, whereby wear of the saw chaln, guide groove 
and the rail portion is prevented so as to improve durability of the main 
body of guide plate and the saw chain. 
A still further object of the present invention is to provide an oil 
supplying structure for a chain saw which is capable of preventing an oil 
supply hole from choking with chips, whereby there is no need to 
frequently remove chips from an oil supply hole. 
A still further object of the present invention is to provide an oil 
supplying structure for a chain saw which is capable of being adapted to 
various types of chain saws having outlet ports whose positions vary 
vertically. 
A still further object of the present invention is to provide an oil 
supplying structure for a chain saw in which the cost of manufacturing the 
main body of a guide plate can be reduced. 
A still further object of the present invention is to provide an oil 
supplying structure for a chain saw in which oil can be continuously 
supplied to a saw chain even if the saw chain jumps and separates from the 
rail. 
A still further object of the present invention is to provide an oil 
supplying structure for a chain saw in which an insertion can be free from 
any runout in the area of a fitting hole in the direction of the 
thickness, whereby lubricating oil can be stably supplied. 
A still further object of the present invention is to provide an oil 
supplying structure which is capable of supplying oil to two sides 
surfaces of a sprocket and an annular sliding portion of the sprocket 
which are provided at the front end of a main body of guide plate, and is 
capable of improving durability of the sprocket and the annular sliding 
portion. 
A still further object of the present invention is to provide an oil 
supplying structure for a chain saw which is capable of supplying oil to 
two sides at any positions in the guide groove whereby efficiency in 
lubrication is improved. 
In order to achieve the above objects, the structure of the present 
invention comprises a pair of rail portions which are provided in the 
outer circumference of the main body of a guide plate, a guide groove 
which is formed between two rail portions, a pair of oil supply holes 
which open toward the guide groove and penetrate the two rail portions 
from outside, a through hole which penetrates the main body of guide plate 
without any connection with the guide groove and a pair of connection 
channels which connect outer openings of oil supply holes and two outer 
openings of the through hole. 
Other and further objects of this invention will become obvious upon an 
understanding of the illustrative embodiments to be described or will be 
indicated in the appended claims, and various advantages not referred to 
herein will occur to one skilled in the art upon employment of the 
invention in practice.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1-4, an embodiment of the present invention will now be 
described. 
Reference numeral 1 represents a main body of a chain saw having a drive 
shaft 2 on one side thereof. Reference numeral 3 represents a sprocket 
which is secured to the drive shaft 2. The sprocket transmits driving 
force of the main body from chain saw 1 to a saw chain to be described 
hereinafter. 
Reference numeral 4 represents a lubricating oil outlet port which opens in 
front (right hand in FIG. 1) of the drive shaft 2 in the main body of 
chain saw 1. Reference numeral 5 represents a pair of bolts which are 
positioned in the lower portion of the outlet port 4. 
Reference numeral 6 represents a main body of a guide plate which is to be 
secured to the main body of the chain saw 1. The guide plate 6 is 
longitudinally adjustablly secured to the chain saw 1 by tightening a nut 
N after inserting a bolt 5 projecting from the main body of above chain 
saw 1, into an oblong hole 8 which is defined at a base end of the main 
body of guide plate 6. The main body of guide plate 6 is integrally 
formed. 
Reference numerals 13a and 13b represent a pair of protector washers which 
are installed between the base end of the above main body of guide plate 6 
and which are the main body of chain saw 1, and installed to the outer 
side of the base end of the main body of guide plate 6. The protector 
washer 13a is provided with a through hole 14 which is located in 
accordance with the outlet port 4 in the main body of chain saw 1. 
Reference numeral 13c represents a chain cover which is secured to the 
outer side of the protector washer 13b, and serves to cover the above 
sprocket 3 as well. 
As shown in FIG. 2 reference numeral 7 represents a guide groove which is 
provided in the form of a recess, and is located on the outer 
circumference of the above main body of guide plate 6. Reference numeral 
15 represents a pair of rails which are provided on the outer 
circumference of the above main body of guide plate 6. 
Reference numeral 9 represents an endless saw chain which is movably 
disposed in the guide groove 7 of the main body of guide plate 6. The saw 
chain 9 is adapted to be driven by a driving force provide by the main 
body of chain saw 1 through the sprocket 3. The saw chain 9 is formed of 
drive links 11, which are disposed in the guide groove 7 of the above main 
body of guide plate 6, and which are driven by the sprocket 3 of the main 
body of chain saw 1, and side links 12. Some of these side links 12 have 
blades 10 in the upper portions thereof, and the links 12 which are 
provided with a blade 10 are arranged at a predetermined interval. The 
drive link 11 is adapted to supply lubricating oil introduced through the 
outlet port 4 in the main body of chain saw 1 to the whole body of the 
guide groove 7 through both sides for the purpose of preventing seizure of 
the saw chain 9 and wear of the guide groove 7, and for the purpose of 
removing chips from the bottom portion of the guide groove 7. 
As shown in FIGS. 1 and 2, reference numeral 16 represents a pair of right 
hand and left hand (FIG. 2) oil supply holes which are located on the 
upper portion and the lower portion of the base end of the main body of 
guide plate 6, and which penetrates a rail portion 15 in the direction of 
the thickness thereof so as to open in the guide groove 7. This oil supply 
hole 16 is located adjacent the outer circumference of the main body of 
guide plate 6. Reference numeral 17 represents through holes which 
penetrate the main body of the guide plate 6 closer to the longitudinal 
axis of the guide than do the oil supply holes 16. These through holes 17 
penetrate the main body of guide plate 6 in the direction of the thickness 
at a position which does not correspond to the guide groove 7. Reference 
numeral 18 represents a connection channel which connects each outer end 
opening 17a of the through hole 17 and each outer end opening 16a of the 
above oil supply hole 16. The connection channels 18 are respectively 
formed on two outer side surfaces of the main body of guide plate 6. Each 
connection channel 18 is covered by the protector washers 13a and 13b from 
outside, and a part of the connection channel 18 adjacent to the outlet 
port 4 is in accordance with the position of the hole 14 of the outer 
protector washer 13a. 
The operation of the chain saw whose structure is mentioned above will now 
be described. 
In normal use, lubricating oil is supplied into the guide groove 7 from 
both sides of the drive link 11 of the saw chain 9 through the outlet port 
4 of the main body of chain saw 1, as shown by the arrow in FIG. 2, and 
through the hole 14 of the protector washer 13a, the through hole 17 of 
the main body of guide plate 6, two connection channels 18, and two oil 
supply holes 16. The lubricating oil is then fed to the whole 
circumference of the main body of guide plate 6 by means of the running 
drive links 11 of the saw chain 9. The lubricating oil is sufficiently 
supplied to the portion between the outer circumferences of two rail 
portions 15 of the main body of guide plate 6, between the inner surface 
of the guide groove 7 and two outer side surfaces of the drive link 11, 
and the portion which connects the drive link 11 of the saw chain 9 and 
the side link 12. 
Since the through hole 17 has no connection with nor opens into the guide 
groove 7, the through hole 17 is prevented from choking or with clogging 
wood chips or sawdust at the guide groove portion 7. 
In this embodiment, the lubricating oil is supplied from a pair of right 
and left oil supply holes 16 to two side surfaces of the drive link 11 of 
the saw chain 9, and the oil supply hole 16 is located adjacent the outer 
circumference of the main body of guide plate 6. The portions to which the 
lubricating oil is not sufficiently supplied in the related art, that is, 
a portion between the inner surface of the rail portion 15 which is 
located opposite to the outlet port 4 and the drive link 11 of the saw 
chain 9, the portion between the outer circumference of the rail portion 
15 which is located opposite to the outlet port 4 and the side link 12 of 
the saw chain 9 and the portion which connects the drive link 11 and the 
side link 12, can now be sufficiently supplied with oil. The saw chain 9, 
guide groove 7 and rail portion 15 are therefore prevented from wear, and 
durability of the main body of guide plate 6 and the saw chain 9 are thus 
improved. 
Since the oil supply hole 16 penetrates the rail portion 15 across its 
thickness and completely crosses the drive link 11, the drive link 11 
removes chips such as wood and so forth from the oil supply hole 16, and 
prevents the oil supply hole 16 from choking with chips when the drive 
link 11 moves. Therefore, it isn't necessary to frequently detach the main 
body of guide plate 6 and saw chain 9 from the main body of chain saw 1 
and remove the chips from inside the oil supply hole 16. 
As the connection channel 18 in the form of an oblong hole is vertically 
provided in the outer side surface of the main body of guide plate 6, the 
main body of guide plate 6 in this embodiment can be applied to various 
types of main bodies of the chain saws 1 having the outlet ports 4 which 
are locate at various positions. Namely, the hole 14 of the protector 
washer 13a which is connected to the outlet port 4 may be located at any 
position over the whole length from the through hole 17 to the oil supply 
hole 16. 
If the position of the main body of guide plate 6 of the chain saw 
according to this embodiment is vertically turned with respect to the main 
body of chain saw 1, the oil supply holes 16, through hole 17 and the 
connection channel 18 which are located in the lower portion correspond to 
the outlet port 4 in the main body of chain saw 1. 
This invention is not limited to the above embodiments, for example, the 
main body of guide plate 6 is formed, as shown in FIG. 5, by interposing a 
center plate 22 between a pair of side plates 21 so as to make a recess 
portion which is formed between the two side plates 21 as a guide groove 
7. In this case, the manufacturing cost can be reduced in comparison with 
the integrally formed main body of guide plate 6 because a precise 
manufacturing is unnecessary for the guide groove 7. 
As shown in FIG. 6, the main body of guide plate 6 may be designed so that 
the circumferetial portions of a pair of side plates 21 are bent outward 
to make a recess portion between two side plates 21 defining the guide 
groove 7 and in which circumferential portions of the two side plates 21 
form the rail portions 15. As shown in FIGS. 7(a) and 7(b), a fitting hole 
23 in the form of an oblong hole may penetrate the main body of guide 
plate 6 at the position adjacent the outer circumference of the rail 
portion 15 so as to extend inwardly relative to the rail portion in FIG. 
7(a) and (b)). An insert 24 having, identically to the previous 
embodiment, the oil supply hole 16, the through hole 17 and the connection 
channel 18 may be fitted into the fitting hole 23. A groove 25 may be 
provided in the form of a recess at a center portion in the direction of 
the thickness of the insert 24 in accordance with the position of the 
guide groove 7 of the main body of guide plate 6. The insert 24 may be 
employed in the main body of guide plate 6 which is formed by a single 
plate or three laminated plates as shown in FIGS. 7(c) and 7(d). 
Moreover, although the insert 24 is to be formed integrally, it may be 
formed by combination of a plurality of members 26 and 27 as shown in FIG. 
8. 
The through hole 17 may be formed, as shown in FIGS. 9(a) and 9(b), by 
fitting a tubular pipe 28 to the main body of guide plate 6 in such a 
manner that the pipe 28 penetrates the two rail portions 15, or may be 
formed by fitting the pipe 28 in such a manner that the pipe 28 penetrates 
the insert 24 in the direction of its thickness. 
Furthermore, the vertical position of the oil supply hole 16 in the main 
body of guide plate 6 may be higher or lower than in the previous 
embodiment, and the number of oil supply holes 16 and the through holes 
17, and the shapes of the supply holes 16, the through holes 17, or the 
connection channel 18 and the shape of the insert 24 may be designed at 
will. 
Although in the previous embodiment, the oil supply hole 16, through hole 
17 and the connection channel 18 are covered by the protector washers 13a 
and 13b from outside, in another embodiment shown in FIG. 10 the holes 16, 
17 and the channel 18 are each covered by a pair of covers 31 and 32 from 
the outside. A connecting hole 33 is formed on the cover 31 adjacent to 
the outlet port 4 at the position corresponding to the position of the 
hole 14 of the protector washer 13a. According to the structure of the 
embodiment hereinbefore described, the oil supply hole 16 can be provided 
closer to the outer circumference of the main body of the guide plate 6 
without any concern for the position of the bent portion 34 of the 
protector washers 13a and 13b. As a result of this provision, the 
lubricating oil can be more efficiently supplied to the saw chain 9. 
Especially, the supply of the lubricating oil to the saw chain 9 is never 
disturbed even if the saw chain 9 separates from the rail portion 15 due 
to jumping during its running. 
In another embodiment shown in FIGS. 11 to 13, fitting holes 41 which 
extend across of the width of the main body of guide plate 6 respectively 
penetrate the upper portion and the lower portion of the base end of the 
main body of the guide plate 6. These holes are preferably formed by 
stamping. An annular securing recess 42 of almost the same diameter as the 
length of the fitting hole 41 is formed in the outer circumference of the 
fitting hole 41 on two sides of the main body of guide plate 6 across the 
thickness thereof. The annular recesses 42 are preferably formed cutting 
or grinding. An insert 44 consisting of a pair of members 43 of the same 
form is inserted into the fitting hole 41 from both sides. A step portion 
45 shaped to fit into the fitting hole 41 is formed on the side surface of 
each disk shape member 43 and an engaging portion 46 shaped to be received 
in the securing recess 42 is provided on the outer circumference of the 
step portion 45. A tubular large diameter fitting portion 47 and a tubular 
small diameter fitting portion 48 having an outside diameter which is 
equal to an inside diameter of the large diameter fitting portion 47 are 
formed below the step portion 45. The small diameter fitting portion 48 of 
one member 43 is received in the large diameter fitting portion 47 of the 
other member 43 while the small diameter fitting portion 48 of the other 
member 43 is received in the large diameter fitting portion 47 of one 
member 43, whereby both members 43 are joined to each other. A pair of 
through holes 17 are formed by inside surfaces of both fitting portions 
47, 48 and there are provided a pair of the oil supply holes 16 through 
each member 43. 
In this modification, the insert 44 is free from any runout in the area of 
the fitting hole 41 in the direction of the thickness because when both 
members 43 are joined, their engaging portions 46 come in contact with the 
securing recesses 42. Therefore, the positions of both the holes 16, 17 
and the channel 18 at the main body of the guide plate 6 are always 
constant, whereby lubricating oil can be continuously supplied. On the 
other hand, the mating portions 47, 48 of both members 43 need not be 
perfectly joined. For example, even if they are joined about half way the 
cooperative engagement of both the members 43 is maintained. Accordingly, 
so long as the depth of the securing recess 42 is substantially equal to 
the thickness of the engaging portion 46, this modification can be used 
also for the main body of a guide plate 6 having a different thickness. 
Moreover, in the embodiment shown in FIGS. 1 to 5, the connection channel 
18 is necessarily provided by cutting or grinding on both sides of the 
main body of guide plate 6, the oil supply hole 16 and the through hole 17 
are thereafter respectively drilled. However, in this modification the 
fitting hole 41 is formed by stamping while the securing recess 42 is 
formed by cutting or grinding. Accordingly the work efficiency during the 
manufacturing can be improved and manufacturing cost reduced. 
Another embodiment is shown in FIGS. 14 and 15. The insert 56, which 
consists of a pair of elliptical members 54 and 55 having a pair of 
flanges 52 on both sides of the outer circumference and a step portion 53 
on the backside, is fitted into an elliptical fitting hole 51. A cover 58 
in the form of a semi-elliptical disc having a flange 57 at the upper 
circumference is inserted from the outside of the member 54 adjacent to 
the outlet port 4 so as to be received into the fitting hole 51 and 
engaged with the member 54. An elliptical cover 60 having flanges 59 in 
both upper and lower portions of the outer circumference is inserted from 
outside the other member 55 so as to be fitted into the fitting hole 51 
and to be engaged with the member 55. This modification can provide 
effects similar to those obtained in the modification shown in FIG. 10. 
Furthermore, it can be applied to the main body of chain saw 1 having an 
outlet port 4 whose vertical position, varies because the cover 58 
adjacent the outlet port 4 is in the form of an elliptical disc. 
A further modification is shown in FIG. 16(a) in which a projecting portion 
61 is formed in the two protector washers 13a and 13b as an alternative to 
the connection channel 18 provided in the main body of the guide plate 6 
so as to connect the oil supply hole 16 and the through hole 17. A further 
modification is shown in FIG. 16(b) in which both the protector washers 
13a and 13b are omitted and the connection channels 18 are defined by 
forming recess portions 62 on the main body of chain saw 1 and the chain 
cover 13c. A further modification is shown in FIG. 16(c) in which the 
connection channels 18 are defined by forming cutout portions 63 on the 
protector washers 13a and 13b and covering the cutout portions 63 by the 
main body of chain saw 1 and the chain cover 13c from outside. 
A still further modification is shown in FIG. 17(a) in which an oil supply 
groove 71 which opens toward the outer peripheral edge of the rail portion 
15 is formed from the oil supply hole 16 for the purpose of smoothly 
supplying oil to the side link 12. In this modification, as shown in FIGS. 
17(b) and 17(c), the structure may be so arranged that an insert 73 having 
the oil supply groove 71 may be inserted into a fitting hole 72 which 
opens toward the outer pheripheral edge of the rail portion 15. 
A further modification is shown in FIGS. 18 and 19 in which a pair of 
connection pipes 81 are arranged in the bottom surface of the guide groove 
7 in both the upper and lower portions of the main body of guide plate 6. 
Lubricating oil is introduced from the through hole 17 to a pair of oil 
supply pipes 82 which are provided on another portion of the main body of 
guide plate 6 in the direction of the thickness through each connection 
pipe 81 for the purpose of supplying oil to both sides in a desired 
portion of the guide groove 7. 
According to this modification, because oil can be supplied to both sides 
of the saw chain 9 at any position of the guide groove 7, efficient 
lubrication can be provided, particularly, for a guide plate of 
considerable length. 
Another embodiment is shown in FIGS. 20(a) and 20(b) in which a pair of 
connection grooves 92 extend from a through hole 17, of formed in the main 
body of guide plate 6 of the triple layer form shown in FIG. 5, to an oil 
chamber 91 which is formed at the front end of the main body of guide 
plate 6, and through a center portion of the main body of guide plate 6 
across its width. The oil chamber 91 is provided with a check valve 93 
operable to prevent the lubricating oil which has been introduced from the 
one connection groove 92 from leaking into another groove 92. A pair of 
oil supply pipes 94 are interposed between the oil chamber 91 and the 
outer circumference at the front end of the main body of guide plate 6 on 
two sides of the main body of guide plate 6 for the purpose of supplying 
oil from the oil chamber 91 to both sides of a sprocket 95. 
According to this embodiment, because oil can be supplied not only to the 
saw chain 9, but also to both sides of the sprocket 95, durability of not 
only the main body of guide plate 6 and saw chain 9 but also the sprocket 
95 can be improved. Furthermore, oil may be supplied to both sides only by 
interposing the oil supply pipe 94 between the respective connection 
groove 92 and the outer circumference at the front end of the main body of 
guide plate 6 while omitting the oil chamber 91 and the check valve 93, 
whereby the manufacturing cost is lower than when the oil chamber 91 and 
the check valve 93 are provided. 
As shown in FIGS. 21(a) and 21(b), the structure may be so arranged that 
the oil supply pipe 94 of the above modification supplys oil to a bearing 
96 which serves as an annular sliding portion of the sprocket 95. In this 
case, the durability of the bearing 96, which is more prone to wear than 
the other members, can be improved. 
Moreover, a vibration proof plate made of vibration proofing material such 
as flexible metal (e.g. lead) or vibration proof rubber and so on can be 
used as the center plate 22 in the aforesaid embodiment or modifications 
in which the main body of guide plate 6 is formed in the triple layers 
structure. In this case, vibration during the operation of chain saw is 
reduced, whereby the work is performed more safely and controllably. 
The modifications shown in FIGS. 10 to 19 can be applied not only to the 
main body of guide plate 6 which is integrally formed but also to that in 
multilayer structures such as double layers, triple layers, five layers 
and so on. 
Moreover, an insert structure can be employed in the modifications shown in 
FIGS. 10, 16, 18 and 20. 
Furthermore, the inserts 24, 44, 56, 73 may be attached to the fitting hole 
by adhesive, rivets, bolts, welding, spot welding and so forth, in 
addition to the aforementioned inserting. 
As many apparently widely different embodiments of this invention may be 
made without departing from the spirit and the scope thereof, it is to be 
understood that the invention is not limited to the specific embodiments 
thereof except as defined in the appended claims.