US3844380A

US3844380A - Power-driven chain saw with automatic and manual lubricating pump

Info

Publication number: US3844380A
Application number: US00443584A
Authority: US
Inventors: W Batson
Original assignee: Singer Co
Current assignee: Ryobi Motor Products Corp
Priority date: 1974-02-19
Filing date: 1974-02-19
Publication date: 1974-10-29
Anticipated expiration: 1991-10-29

Abstract

A power-driven chain saw having a lubricating pump for the saw chain and/or guide bar. A pump housing has a pump chamber and lubricating fluid inlet and outlet passages communicating therewith and a plunger reciprocable therein. A wobble ring having planetary elements positioned therewithin is connected operably with the plunger, said wobble ring being movable so as to cause reciprocation of said plunger. A sun element is operably connected to the drive for the saw chain and the pair of planetary elements are driven by the sun element around same and within the wobble ring. A difference in the diameter between the planetary elements results in vertical movement of the wobble ring to cause reciprocation of the plunger.

Description

United States Patent [1 Batson 1 Oct. 29, 1974 1 POWER-DRIVEN CHAIN SAW WITH AUTOMATIC AND MANUAL LUBRlCATlNG PUMP [75] Inventor: William A. Batson, Pickens, SC.

[73] Assignee: The Singer Company, New York,

221 Filed: Feb. 19,1974

[2]] Appl. No.: 443,584

Primary Examiner-Al Lawrence Smith Assistant Examinerl. C. Peters Attorney, Agent, or FirmR0bert E. Smith; Edward L. Bell; Joel Halpern [57] ABSTRACT A power-driven chain saw having a lubricating pump for the saw chain and/or guide bar. A pump housing has a pump chamber and lubricating fluid inlet and outlet passages communicating therewith and a plunger reciprocable therein. A wobble ring having planetary elements positioned therewithin is connected operably with the plunger, said wobble ring being movable so as to cause reciprocation of said plunger. A sun element is operably connected to the drive for the saw chain and the pair of planetary elements are driven by the sun element around same and within the wobble ring. A difference in the diameter between the planetary elements results in vertical movement of the wobble ring to cause reciprocation of the plunger.

14 Claims, 9 Drawing Figures 20 70 se\ i 3 BACKGROUND OF THE INVENTION This invention relates to power-driven chain saws and more particularly to such a saw which incorporates a gear-driven automatic lubricating pump and a hand pump.

A typical prior art lubricating pump involves the pro vision of a pump chamber or cylinder within the transmission housing of the chain saw and in which a plunger is reciprocated to draw lubricating oil from a reservior through oil inlet passages into the cylinder from which it is discharged to the guide rail or guide bar for the saw chain. An eccentric member carried by the sprocket shaft is provided with a collar which connects with the plunger and effectuates reciprocation thereof concomitant with rotation of the sprocket shaft.

The disadvantages of such eccentric plunger actuating mechanisms are principally twofold: l) the eccentric or cam mechanism tends to develop a wiping action during plunger reciprocation, and (2) the plunger is forced to reciprocate with each revolution of the drive shaft, thus being generally limited to high cyclical operational rates. The first disadvantage leads to undue and uneven wear of both the cylinder and plunger with the attendant generation of heat and ultimate loss of pumping pressure. The second of such disadvantages serves to accelerate the wear and tear on all moving parts of the pump assembly, including any check valves which may be utilized.

Other known pump constructions require "that a substantial area within the housing be allocated for the pump. Such space is at a premium, particularly in a direction axially of the shaft utilized to drive the pump mechanism.

SUMMARY or THE INVENTION One object of the present invention is the provision of a power-driven chain saw having an automatic lubricating pump incorporated therein which delivers metered amounts of lubricant.

Another object of the invention is the provision of a power-driven chain saw having an automatic lubricating pump incorporated therein which is capable of operation at a reduced cyclical rate.

Still another object ofthe invention is the provision of a power-driven chain saw having an automatic lubricating pump incorporated therein which generates a reduced amount of heat and has an increased service These and other objects and advantagesoftheinvention will become readilyapparent from the description of the invention which follows'hereinafter.

According to this invention there is provided in a power-driven chain saw having a saw chain and a saw thereon, a sprocket shaft rotatably supporting said 2 chain, a guide bar for guiding said saw chain along a predetermined path, and a lubricating pump which includes a reeiprocable plunger for supplying lubricant for said saw chain, the improvement which comprises:

a. a wobble ring mounted so as to cyclically reciprocate said plunger in a predetermined time-phase relationship with the rotation of said saw chain;

b. a sun element mounted within said wobble ring operably connected to the driving means for said chain saw; and

c. at least one planetary member interposed between said sun element and said wobble ring, the relationship between said planetary member and said wobble ring being such that said planetary member rotates within said wobble ring to periodically reach positions therewithin whereby said wobble ring is caused to rise and fall and thus cause reciprocation of said plunger.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more fully comprehended it will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. I is a perspective view of a power-driven chain saw embodying the invention;

FIG. 2 is a sectional view of the lubricating pump mechanism taken along lines 2-2 .of FIG. 1;

FIG. 3 is a side elevation of the pump mechanism shown in FIG. 2, partly in section, taken along lines .3-3 of FIG. 2;

FIG. 4 is a diagrammatic sketch of the gearing of the pump mechanism showing the planet gears in one position for reciprocation of the pump plunger downwardly;

FIG. 5 is a diagrammatic sketch similar to FIG. .4 with the planet gears in a second position for reciprocation of the pump plunger upwardly;

FIG. 6 shows diagrammatically the preferred planet gears for use in the pump construction of the invention;

FIG. 7 is a crosssection similar to that of FIG. 2 but omitting the gearing and pump drive shaft and showing the hand pump feature of the invention; and

FIGS. 8 and 9 are diagrammatic sketches of the pump chamber, plunger and ball check valves showing the plunger and valves in different operative positions.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, and FIG. 1 in particular, there is shown a power-driven chain saw 10 having a housing 12 which contains an electric motor (not shown) which is energizable .by switch means (not shown) which maybe mounted in the housing at a convenient locationconnectable to a source of electricity by electric conduit .13. The housing is givena tophandle I4and rearwardly extending handle 16 by means of which the chain sawcan be easily heldand controlled during operation. The housingis provided with a.knob 18 which isintegral with a slidablehandpump 20 (see FIG. 7) :tobedescribed in-detail.hereinafteLCap 2 2 is secured tothe housing in the outlet of the lubricating oil reservoir. To add lubricating oil, itis merely necessary to-remove cap 22. Knobs '24 and Z26are respectively the adjustment knob and cutter sharpening knob to be employed for sharpening of the chain saw.

The front housing 28 of the saw chain encloses the sprocket end of the drive shaft which carries the saw chain 32. One end of a guide bar 34 is suitably clamped within the housing 28. Guide bar 34 extends outwardly of the housing and is provided with a slot or groove for receiving saw chain 32 thereon so that it can be guided along the periphery of the guide bar. A nose roller 35 is provided at the outer end of the guide bar to facilitate running and return of the saw chain. A lubricating pump 36 supplies lubricating fluid such as a suitable oil to the groove of the guide bar and/or the saw chain to permit smooth operation of the saw chain. The construction of the lubricating pump will be hereinafter described in detail.

As shown most clearly in FIGS. 2, 3 and 7 the lubricating pump 36 is mounted internally of the saw. The pump includes a plunger 38 which is slidably positioned within pump chamber 39 of a cylindrical bore 40 formed in block 42. One or more pairs of rings 44 are positioned within circumferential grooves of the plunger for sealing against the leakage of oil from the pump chamber past the plunger during the compression stroke of the plunger.

Block 42 in the housing of the chain saw is provided with a pair of

passageways

46, 48 which communicate respectively at one end via

ball check valves

50, 52 with inlet and

discharge conduits

54, 56 for the lubricating fluid. The other end of passageway 46 opens into the upper portion of cylinder 40. At such point the passageway is in communication with a duct which is formed in a sleeve member 58.

Sleeve 58 is mounted slidably in cylinder 40 and is urged normally towards the upper extremity of its travel within the cylinder by spring 60. Stop 62 is provided on the sleeve to limit the extent of its upward and downward movement. The linear traverse of sleeve 58 is determined by the depth of a transverse bore 64 formed in block 42 which acts cooperably with stop 62. The sleeve is desirably provided with 0 rings 61 in the same manner as plunger 38.

Sleeve 58 is given a central opening 66 by which lubricating fluid may pass from the reservoir (not shown) through inlet conduit 54, check valve 50, and passageway 46 into the pump chamber 39. A needle valve 68 is seated in opening 66 and regulates the quantity of lubricant which is caused to flow into the pump chamber. A slotted head 70 atop the needle valve affords ready adjustment of the position of the needle valve with respect to opening 66 to provide such regulation. Slotted head 70, as shown, is desirably nested within the confines of knob 18 which serves as the handle for a manual pump which will be described below.

Passageway 48, at its end remote from check valve 52, communicates with the lower region of pump chamber 39 above the uppermost level to which plunger 38 may be reciprocated. Thus, lubricating fluid within chamber 39 and between the lower end face of sleeve 58 and the top surface of plunger 38 may be pressured out of the chamber 39, through passageway 48, check valve 52 and outlet conduit 56 to either the guide bar and/or saw chain to supply lubricant thereto either by the upwards reciprocation of the plunger during automatic operation of the pump or by the manual depression of knob or handle 18 which serves to lower sleeve 58 within cylinder 40.

From the foregoing it will be seen that knob or handle l8, sleeve 58 and pump chamber 39, in conjunction with the inlet and outlet passageways and conduits, provides a hand pump for the saw which is operable independently of the automatic lubricating pump to be subsequently described.

Positioned within the housing for the saw, directly beneath block 42 and cradling the lower end thereof, is gear box 72. .lournaled rotatably within the gear box and supported by bearings 74 is drive shaft 76 which may conveniently be the shaft carrying the sprocket (not shown) for the saw chain. Mounted on shaft 76 to rotate therewith is a sun element 78 depicted in the form of a gear.

Planetary members

80 and 82 are rotatably mounted within the gear box in driving engagement with and in diametrically opposed positions upon sun element 78. The

planetary members

80, 82 are also shown in FIGS. 3 and 6 as being gears. However, it will be understood that the concept of the invention is equally applicable to the use of friction wheels or equivalent elements which may be drivingly engaged. Further, although two planetary members are shown it will be appreciated that by suitable design it is possible to employ a single eccentrically shaped planetary member. A wobble ring shown in the form of an internal gear 84 with the teeth thereof in meshed relationship with the planet gears surrounds same. Where the planetary members employed take a form other than gears it will be recognized the gear ring 84 will take a complementary form. The internal gear, as shown in the presently preferred embodiment of the invention, is prevented from rotating by virtue of a keeper member 86 which is carried fixedly by the portion of the gear box adjacent an appropriate region of the internal gear. The internal gear at such region is provided with a notch 88 therein within which the outer end of keeper member 86 is retained and which permits limited radial movement of gear 84 relative to drive shaft 76 and gear box 72, principally along the line of motion of plunger 38; however, no rotation of the gear 84 is permitted. It is to be understood, however, that the internal gear ring 84 may be freely movable or rotatable. In such event, where gears are employed, the specific gear ratios between the planet gears and the internal gear are selected so as to effectuate the desired cyclical rise and fall of the ring gear through rotation of the planet gears within the internal gear ring at the desired rate relative to rotation of shaft 76. By so designing the notch for the keeper member 86 the movement of the wobble ring can be so regulated that its motion is substantially along the line of plunger reciprocation to thereby substantially eliminate any wiping action.

As shown in FIG. 3, the axes of the sun gear 78, planet gears 80 and 82 and desirably also the internal gear 84 are aligned radially. It will be understood, however, that it is possible to achieve the desired results without precise radial alignment. Preferably they are arranged along a line which is common to the reciprocal path of plunger 38 to minimize wiping of the plunger. However, it will be understood that precise alignment with the reciprocal path of the plunger is not essential to the invention. The wobble ring 84 is provided with a collar 90 to which is connected the lower end of plunger 38 to be reciprocated by the wobble ring in the manner to be described. In FIG. 2, the plunger is shown at its uppermost position ready to descend. As will be noted, both of

check valves

50, 52 are closed by the seating of the balls in both valves by their respective associated springs. The hand pump 20 is shown in its normally inoperative state.

The diametral pitch of the sun gear, planet gears and internal gear is desirably the same to insure smoothness of action between such gears. The planet gears 80, 82 should be provided with a dissimilar number of teeth. According to the presently preferred embodiment planet gear 80 is provided with one tooth more than planet gear 82. Where all of the aforementioned gears have a diametral pitch of 32 the number of teeth on

gears

80 and 82 should thus be 20 and 19 respectively.

Due to the difference in the number of teeth pro vided on the planet gears, and the provision of either a nonrotatable internal gear or a suitable selection of gear ratios between the planet gears and internal gear it will be appreciatedthat the planet gears, upon rotation of drive shaft 76 and its associated sun gear 78, will walk around the internal gear. When planet gear 80 reaches the zenith of its path within the internal gear, as depicted in FIG. 5, planet gear 82 will be located at its lowermost point. In this rotative position the wobble ring will be caused to rise a distance which is determined by the difference in the number of teeth carried by the planet gears and the diametral pitch of such gears. Where, as aforesaid, planet gear 80 is provided with 20 teeth and planet gear 82 is provided with 19 teeth and the diametral pitch for the gears is 32, the wobble ring (internal gear 84) will rise 1/32 inch. This in turn, willeffect an upward movement of plunger 38 by the same amount. In FIG; 4, the planet gears have walked to a positionreverse from thatshown in FIG. 5 to thereby effectuate a drop of 1/32 by the wobble ring and plunger.

It will be further appreciated that by selective design of the gearing one can provide for the desired stroke of the plunger and thereby deliver any designed quantity of lubricant to the saw chain and/or guide barper unit time. The present specification has not been encumbered with a disclosure of the conduits needed to convey lubricant from discharge conduit 56 to the exact point of distribution or to supply lubricant from the reservoir to inlet conduit 54 since various arrangements may be employed and it is well within the knowledge of persons skilled in this art to provide such conduitry.

FIG. 6 illustrates diagrammatically the relative sizes of planet gears 80, 82 having the same diametral pitch but a different number of teeth. The difference in diameter d will be a function of the difference in the number of teeth and the diametral pitch. As stated above, where the teeth on planet gears 80 and 82 are 20 and 19 respectively, and the diametral pitch is 32, d will be l/32 inch.

FIG. 7 depicts the hand pump 20 in its actuated state. Knob or handle 18 has been depressed, thereby forcing sleeve 58 downwardly into pump chamber 39. Such movement of the sleeve induces a flow of lubricant from inlet conduit 54, through the check valve 50 (thereby urging the ball 94 against the force of spring 96 to open the valve), through passageway 46, into the passage through sleeve 58 and into pump chamber 39. Further downward movement of the sleeve 58results in the flow of lubricant into passageway 48 and against the spring-biased ball 100 of check valve 52. Thelubri- 6 cant is thus forced into discharge conduit 56 and'out to the point or points of distribution. It will thus be seen that hand pump 20 is actuable independently of the automatic lubricating pump 36 which utilizes plunger 38, the gearing of gear box 72, etc.

FIGS. 8 and 9 show the path of lubricant through the

check valves

50, 52 by the arrows indicated therein. It will be seen that lubricant is drawn into pump chamber 39 through check valve 50 upon downward movement of plunger 38. During such descent of the plunger the pressure of lubricant upstream of the ball 94 causes a compression of spring 96, opening the valve and permitting a flow of lubricant into the pump chamber 39. Since the volume of chamber 39 above the plunger 38 is increasing, there is insufficient build-up of pressure to unseat ball 100. However, as shown by the diagrammatic sketch of FIG. 9, as the plunger rises within cylinder 40the actual pumping chamber 39 diminished in volume with a resultant increase in pressure on the lubricant contained therein. The end result is thatonce the pressure increases sufficiently it causes the unseating of ball and the flow of lubricant through the check valve 52 to discharge conduit 56 and to distribution. During the ascent of the plunger the elevated pressure within chamber 39 serves to insure seating of ball 94 on its seat to retain check valve 50 in its closed condition. The operation of ball check valves is not novel per se; however, when combined with the unique handand automatic lubricating pump construction hereinbefore described the use and positioning of

check valves

50, 52 is particularly effective.

Numerous alterations of the structure herein disclosedwillsuggest themselves to those skilled in the art. However, it is to be understood thatthe present disclosure relates to a preferred embodimentof theinvention which is for purposes ofillustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Having thus set forth the nature of the invention, what is claimed herein is:

1. In a power-driven chain saw having a saw chain and a saw thereon, a sprocket shaft rotatably supporting said chain, a guide bar for guiding said saw chain along a predetermined path, and :a lubricating pump which includes a reciprocable plunger for supplyinglu bricant for said saw chain, the improvement which comprises:

c. at least one planetary member interposed between said sun element and said wobble ring, the relation ship between said planetary member and said wobble ringbeing such that said planetary member rotates within said wobble ringto periodically reach positions therewithin whereby said wobble ring is caused to rise and fall and thus cause reciprocation of said plunger.

2. A power-driven chain saw according to claim 1,

5 wherein said wobble ring comprises an internal gear ring, said sun element comprises a sun gear, and said planetary member comprises a pair of planetary gears.

3. A power-driven chain saw according to claim 2, wherein the first of said planetary gears has a greater number of teeth than the other of said planetary gears.

4. A power-driven chain saw according to claim 3, wherein said internal gear ring is mounted so as to be non-rotatable but movable along a line which is substantially common to the reciprocal path of said plunger.

5. A power-driven chain saw according to claim 1, wherein a housing is provided for said pump which comprises a block having a cylindrical bore therein, said plunger being slidably positioned within said cylindrical bore and defining the lower wall of a pump chamber therein, inlet and outlet passages being provided in said block communicating with said pump chamber for the admission thereto and the withdrawal therefrom of lubricating fluid.

6. A power-driven chain saw according to claim 2, wherein said first and second planet gears have their axes of rotation located along a line passing radially through the axis of rotation of said sun gear; said line substantially defining the principal line of motion of said plunger.

7. A power-driven chain saw according to claim 6, wherein the diametral pitch of said ring gear, sun gear and said first and second planet gears is the same.

8. A power-drive chain saw according to claim 6, wherein said sun gear is mounted by the sprocket drive shaft.

9. A power-driven chain saw according to claim 8, wherein the housing for said pump is associated with the transmission housing for the chain saw.

10. A power-driven chain saw according to claim 4, wherein a notch is provided in said ring gear and a keeper member is carried fixedly by the housing which surrounds at least the portion of said ring gear gaving said notch therein, said keeper member extending into said notch to prevent rotation of said ring gear and permitting limited radial movement thereof principally along the line of motion of said plunger.

11. A power-driven chain saw according to claim 5, wherein a combination hand pump and needle valve is slidably mounted within the cylindrical bore of said pump housing, said needle valve being in communication with said lubricating fluid inlet and with the upper portion of said pump chamber whereby the amount of lubricating fluid which is drawn into said chamber may be regulated.

12. A power-driven chain saw according to claim 11, wherein said combination hand pump and needle valve comprises a sleeve positioned within the upper region of said cylindrical bore having its lower end face in spaced relation to said plunger, said needle valve being carried within said sleeve and movable axially thereof so as to regulate the amount of lubricant flowable through said sleeve into said pump chamber.

13. A power-driven chain saw according to claim 11, wherein spring means is mounted within said cylindrical bore to bias said hand pump into a normally inoperative position.

14. A power-driven chain saw according to claim 5, wherein said lubricating fluid inlet and outlet passages are provided with spring-loaded ball check valves to prevent back flow of lubricating fluid.

Claims

1. In a power-driven chain saw having a saw chain and a saw thereon, a sprocket shaft rotatably supporting said chain, a guide bar for guiding said saw chain along a predetermined path, and a lubricating pump which includes a reciprocable plunger for supplying lubricant for said saw chain, the improvement which comprises: a. a wobble ring mounted so as to cyclically reciprocate said plunger in a predetermined time-phase relationship with the rotation of said saw chain; b. a sun element mounted within said wobble ring operably connected to the driving means for said chain saw; and c. at least one planetary member interposed between said sun element and said wobble ring, the relationship between said planetary member and said wobble ring being such that said planetary member rotates within said wobble ring to periodically reach positions therewithin whereby said wobble ring is caused to rise and fall and thus cause reciprocation of said plunger.

2. A power-driven chain saw according to claim 1, wherein said wobble ring comprises an internal gear ring, said sun element comprises a sun gear, and said planetary member comprises a pair of planetary gears.