US3923126A - Band type brake for a chain saw - Google Patents

Band type brake for a chain saw Download PDF

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Publication number
US3923126A
US3923126A US483034A US48303474A US3923126A US 3923126 A US3923126 A US 3923126A US 483034 A US483034 A US 483034A US 48303474 A US48303474 A US 48303474A US 3923126 A US3923126 A US 3923126A
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United States
Prior art keywords
brake
drum
chain
band
rotatable member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US483034A
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English (en)
Inventor
Edward J Bidanset
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Textron Inc
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Textron Inc
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Publication date
Application filed by Textron Inc filed Critical Textron Inc
Priority to US483034A priority Critical patent/US3923126A/en
Priority to SE7506970A priority patent/SE426454B/xx
Priority to BR4895/75D priority patent/BR7503806A/pt
Priority to NO752209A priority patent/NO143090C/no
Priority to DE2527812A priority patent/DE2527812C2/de
Priority to JP50075782A priority patent/JPS5239199B2/ja
Priority to CA230,009A priority patent/CA1027882A/en
Priority to GB2691475A priority patent/GB1456014A/en
Application granted granted Critical
Publication of US3923126A publication Critical patent/US3923126A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
    • B27B17/00—Chain saws; Equipment therefor
    • B27B17/08—Drives or gearings; Devices for swivelling or tilting the chain saw
    • B27B17/083—Devices for arresting movement of the saw chain
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D49/00—Brakes with a braking member co-operating with the periphery of a drum, wheel-rim, or the like
    • F16D49/02—Brakes with a braking member co-operating with the periphery of a drum, wheel-rim, or the like shaped as a helical band or coil with more than one turn, with or without intensification of the braking force by the tension of the band or contracting member
    • F16D49/04—Brakes with a braking member co-operating with the periphery of a drum, wheel-rim, or the like shaped as a helical band or coil with more than one turn, with or without intensification of the braking force by the tension of the band or contracting member mechanically actuated

Definitions

  • ABSTRACT An inertial-manual actuating safety brake for a chain saw in which a mechanical integrator distinguishes between relatively long duration accelerations developed by a kickback producing impulse and normal operating accelerations associated with operational and vibratory forces.
  • the operation of the integrator causes the nullifica'tion of the operational and vibratory forces.
  • Occurrences of a kickback" impulse developing a force of required magnitude, direction, and duration causes a spring-mass accelerometer to change from a brake released to a brake applied condition, applying a braking torque to the saw chain.
  • the accelerometer utilizes a pivotable hand guard as the actuating mass.
  • the hand guard also provides for manual operation. In manual operation the release force is applied manually.
  • BAND TYPE BRAKE FOR A CHAIN SAW FIELD OF THE INVENTION might cause injury to the user or nearby co-workers.
  • the invention relates to means for sensing the occurrence of an uncontrollable kickback, or other rapid motion directed away from the cutting surface toward the operator and thereupon bringing the chain to a stopf BACKGROUND OF THE INVENTION
  • an uncontrollable kickback or other rapid motion directed away from the cutting surface toward the operator and thereupon bringing the chain to a stopf BACKGROUND OF THE INVENTION
  • the widespread use of portable power tools in the construction, lumbering, and consumer markets has emphasized the need for effective user safeguards. Lighter weight, reduced vibration, and higher power have resulted in very efficient cutting tools that are used in increasing applications by skilled "and semiskilled operators, and as with any powered machine they present a potential hazard to the user. In the case of chain saws a potential hazard is presented by the phenomenon known as kickback.
  • a kickback can be produced by a chain saw when the cutting elements on the chain momentarily stop" cutting and are seized by the work material.
  • the kinetic energy of the chain normally used to remove the material is suddenly transferred to the chain bar impartin'g a force to the'chain bar that causes it to kick up toward the operator.
  • the magnitude of the kickback force' is related to the spe'edof the chain and the nature'of engagement of the chain with the work material.
  • safety devices place a manually operated hand guard actuator in a position to be contacted by the back of the hand or wrist of the operator in the event of a kickback and thereupon actuate a chain brake device manually to apply the brake and stop the saw chain.
  • the clearance between the front'handle and the brake actuator necessary to allow convenient operation of the chain saw requires a large angle of rotation of the saw about the wrist before actuation occurs. This large angle of rotation allows the driven chain to approach the user a considerable distance before actuation of the brake occurs. Additionally, the operator in attempting to protect himself may remove his hand from the hand grip without actuating the brake. Another possibility is for the user to firmly grip the chain saw during the kickback, so that the users arms and chain saw act as a rigid body rotating about an external point.
  • a braking device in accordance with the invention comprises three basic components; a mechanical integrator, a spring-mass ac celerometer inertial sensor,'and a brake.
  • Several of the parts serve a duality of function. Due to the multiplicity of cutting conditions and unpredictability of operator reaction, it is impossible to predict the motion of the I saw during a kickback. It is reasonable though to assume that during the'throw impulse, i.e. that duration of time the sawchain and work material are in contact during the production of a kickback, and shortly thereafter, the motion is confined to the plane of the cutting bar.
  • This invention utilizes this concept inertially to sense a potentially hazardous motion produced bythe kickback production impulse directed toward the user, and to initiate a sequence and apply a brake to the clutch drum and sprocket driving'the saw chain. Inertiallysensing the production impulse to initiate the braking sequence eliminates human reaction from the braking function and provides the maximum available time to stop the motion of the'chain.
  • the mechanical integrator provides an-integrating device to nullify extraneous motion of the accelerometer mass produced by vibration and normal cutting forces.
  • the integrator distinguishes between these short duration forces and the relatively'long duration force developed during thejproduction of a kickback by sensing the direction,'niagnitude, and duration of the sustained force.
  • the integrating accelerometer consists of a pivotable hand guard and rotatable control member in cooperative operation with an operating member and a control spring.
  • the integratoraccelerometer obeys the equation of motion for a single degreeof freedom system expressed by the second order differential equation of motion:
  • the inertial property of the hand guard-rotatable control member causes it to remain stationary with respect to the inertialreference while the chain saw rotates through the kickback arc.
  • the relative motion between the hand guard and the chain saw causes the brake to be applied.
  • the total braking torque developed by this configuration may be varied to meet specific applications by varying M, u, or 0.
  • Braking pressures may be varied by adjusting M or A, where A represents the contact area between the brake band and the clutch drum.
  • the brake band may have any suitable cross sectional configuration but in some applications it is desirable to minimize the contact area to control the brake pressures.
  • a square or rectangular cross sectional brake band may allow a hydrodynamic oil film to exist between the brake band and brake drum, creating in effect a journal bearing.
  • a round cross sectional brake band providing an equivalent braking torque will produce higher braking pressures due to the smaller contact area, and effectively break through an existing oil film, thereby increasing the occurrence of contact between the brake band and drum surfaces.
  • the cross sectional shape is not limited to a round section, but may be shaped to suit the particular application.
  • Another brake band configuration compatible with the inertial sensing features described above consists of an untempered multi-tum element, firmly anchored at one end and externally tensioned by an operating member. This design obeys the equation:
  • the brake comprises a narrow spring brake band which is wrapped in a helical coil around the drum of a centrifugal clutch through which the chain is driven.
  • the brake band wraps 1% turns and preferably between 1 /2 and 2 /2 turns around the clutch drum.
  • the inside diameter of the helical coil of the spring brake band is less than the outside diameter of the clutch drum so that the brake band tends inherently to grip the drum.
  • the leading end of the spring brake band is anchored while the trailing end is controlled by an operating member which is rotatably supported for movement between a brake releasing position in which the helical coil of the spring brake band is expanded so as to free the clutch drum and a brake applying position in which the helical coil of the spring brake band contracts so that the band grips and brakes the drum to bring it quickly to a stop.
  • the operating member is controlled through a mechanical integrator by a springmass accelerometer inertial sensor which is responsive to predetermined acceleration of the chain saw. During normal operation of the saw, the inertial sensor acting through the mechanical integrator retains the operating member in brake releasing position.
  • the inertial sensor senses the acceleration of the saw and initiates movement of the operating member to brake applying position, thereby applying the brake quickly to stop the saw chain.
  • the inertial device comprises a rotatable control member carrying an eccentric mass.
  • the inertial property of the sensor causes the rotatable member to remain stationary in space while the chain saw experiences an acceleration.
  • the resulting relative motion causes an apparent relative rotation of the control member in a direction to initiate movement of the brake applied position.
  • the eccentric mass is preferably in the form of a handle portion which provides for manual operation, both to trip and to reset the brake controlling mechanism.
  • FIG. 1 is a side view of a chain brake in accordance with the present invention and associated portions of a chain saw, the chain brake being shown in released condition;
  • FIG. 2 is a sectional view taken approximately on the line 2-2 in FIG. 1;
  • FIG. 3 is a side view with the chain brake in applied condition
  • FIG. 4 is a side view corresponding to a portion of FIG. 1 but showing another embodiment.
  • FIG. 1 of the drawings a chain brake in accordance with the present invention is shown by way of example installed on the drive case cover 1 of a chain saw.
  • the drive case cover can for example be a suitable casting of the configuration shown in the drawings.
  • a guide bar (not shown) is mounted on the saw chain chassis by bolts passing through holes 2 in the drive case cover.
  • a cutting chain (not shown) which runs on the guide bar is driven by a sprocket 3 on the drum 4 of a centrifugal clutch, the expansible rotor of which is driven by the chain saw engine.
  • the centrifugal clutch has the characteristic that when the engine is running at idling speed, the rotor is disengaged from the drum so that the drum, sprocket and cutting chain are not driven.
  • the centrifugal clutch engages so as to drive the drum 4 and hence the chain.
  • the clutch drum 4 has a cylindrical rim portion 4a at the periphery of a radial wall portion 4b on which the sprocket 3 is mounted.
  • the clutch drum may for example have a diameter of about 2 /2 to 3 inches with a rim portion about 0.7 inches wide.
  • a brake band 5 is wrapped around the peripheral rim 4a of the drum 4 of the centrifugal clutch.
  • the brake band 5 comprises a narrow spring band or ribbon having a cross sectional shape providing limited contact with the drum.
  • the band may be of round or oval cross section.
  • the band is preformed so as to provide a lower straight portion 5a, a central portion 512 which is wrapped helically around the brake drum and a straight upper portion 50.
  • the lower straight portion 5a of the brake band is anchored to the drive case cover 1 by means of a screw 6 which passes through a loop 5d formed at the end of the band.
  • the loop 5d is sufficiently large to be captured between projecting flange portions la and 1b of the drive case cover so as to be held even if the screw 6 should come loose.
  • the central portion 5b of the brake band is formed as a helical coil which surrounds the clutch drum 4. As seen in FIG. 1, the clutch drum turns in a counterclockwise direction so that when the brake band engages the drum, frictional forces acting on the band tend to provide a self-activating force to pull the band tighter on the drum.
  • the brake band 5 should preferably make at least 1 turns abound the clutch drum. On the basis of present experience good results are obtained by using 1 /2 turns to 3% turns.
  • the brake band wraps around the clutch drum approximately 2% turns.
  • the brake band is preferably preformed so that the internal diameter of the helically coiled portion 5b in a relaxed condition is smaller than the external diameter of the clutch drum. Hence, unless held in an expanded condition, the helically coiled portion of the brake band contracts so as to grip the clutch drum.
  • the straight end portions 5a and 5b of the brake band extend essentially tangentially of the clutch drum.
  • expansion of the brake band coil is effected by an operating member 8 which is rotatably mounted by means of a shouldered screw 9 which is screwed into a tapped hole provided in the drive case cover.
  • An arm 8a of the operating member 8 is adapted to engage the head 10a of a button 10 provided on the end of the upper straight portion 50 of the brake band 5.
  • a stern portion 10b of the button is received in an elongated slot in a guide plate 11 and is retained by a snap ring See.
  • the plate 11 guides the end of the brake band laterally while permitting movement tangentially of the clutch drum and also movement toward and away from the drum.
  • the operating member 8 is angularly movable about its axis of rotation between two positions as illustrated respectively in FIG. 1 and in FIG. 3. In the position shown in FIG. 1, the arm 8a of the operating member 8 presses on the button 10 provided on the trailing end of the spring brake band so as to expand the helically coiled portion 5b of the brake band and thereby disengage the brake band from the clutch drum.
  • the drive case cover is provided with suitable abutment portions 1c which engage the brake band when in expanded condition and assist in positioning it so that the helically coiled portion of the brake band is concentric with and spaced from the periphery of the clutch drum.
  • the brake is' thus released and the clutch drum is free to turn.
  • the operating member 8 has turned in a clockwise direction so as to relieve the pressure on the button 10 on the trailing end of the spring brake band.
  • the brake band by its inherent resilience contracts and grips the clutch drum.
  • Operation of the operating member 8 to release or to apply the brake is controlled by an inertial sensor device which is responsive to predetermined acceleration of the chain saw.
  • the inertial device retains the operating member 8 in brake releasing position so that the clutch drum 4 is free to turn.
  • the inertial device releases the operating member 8 so as to move to the position shown in FIG. 3 thereby applying the brake and quickly stopping the clutch drum.
  • the inertial sensor comprises a control member 12 rotatably mounted on the drive case cover for rotation about an axis which is parallel to and spaced from the axis of rotation of the operating member 8.
  • the control member 12 is rotatably mounted by means of an antifriction bearing 13 on a shouldered screw 14 which is screwed into a tapped hole in the drive case cover.
  • the control member 12 is rotatable relative to the drive case cover by inertia responsive means comprising a mass or weight disposed eccentrically of the axis of rotation of the control member and a control spring.
  • the eccentric mass or weight is shown by way of example as comprising a handle or guard member 15 in the form of a tube bent in loop configuration. Ends of the tube are received in sockets provided in an upwardly extending portion of the control member 12 and are secured by a pin 16.
  • the center of gravity of the mass comprising the member 15 and its connections to the control member 12 is eccentric of the axis of the control member, sudden acceleration of the saw results in movement of the saw relative to the control member and eccentric mass which tend to remain stationary by reason of their inertia.
  • the result is an apparent rotation of the control member 12 and guard member 15 with respect to the saw. For example, in the event of a kickback whereupon the saw is moved angularly in a clockwise direction as viewed in FIG. 1, inertial force acting on the eccentric mass result in relative rotation of the control member 12 in a counterclockwise direction.
  • the guard member 15 provides a handle by means of which the control member 12 can be rotated manually.
  • the member 15 extends across the front upper portion of the power head of the saw and is located in front of and somewhat higher than the front handle by which the saw is held. In FIG. 1, the location of the front handle is indicated by the circuit H.
  • the guard member 15 is engageable by the hand or wrist of the operator when the saw kicks up, thereby resulting in rotation of the control member 12 in a counterclockwise direction relative to the saw.
  • the guard member also provides convenient handle means for manually rotating the control member 12 in a clockwise direction to reset it to its normal position as shown in FIG. 1.
  • Operative connections are provided between the control member 12 and the operating member 8 so as to provide for control of the braking action by the inertial sensor.
  • the operating member is retained in a brake releasing position by the control member 12 during normal operation of the chain saw.
  • an inertial force acting through the inertial sensor comprising the guard member 15 and control member 12, cause the operating member to rotate to brake applying position.
  • the operative connections between the control member 12 and the operating member 8 are shown in the drawings as comprising an abutment 12a on the control member engageable with an abutment 8b on the operating member 8 to move the operating member in a counterclockwise direction when the control member is moved in a clockwise direction.
  • a tension spring 18 extends between a pin 19 on the operating member 8 and a pin 20 on the control member 12.
  • the location of the pins 19 and 20 is such that when the operating member 8 and the control member 12 are in set position as illustrated in FIG. 1, the spring holds the abutment 12a of the control member and the abutment 8b of the operating member in engagement with one another and also holds a peripheral surface 80 of the operating member against a peripheral surface 12b of the control member 12.
  • the surface 12b is of constant radius concentric with the axis of rotation of the control member 12.
  • the operating member 8, control member 12 and spring 18 comprises a mechanical integrator by means of which the braking action is controlled so as to apply the brake only when movement of the saw as sensed by the inertial sensor is of a predetermined direction, rate of acceleration and duration.
  • the mechanical integrator discriminates between short duration sinusoidal accelerations generated by the engine and long duration accelerations caused by a kickback producing impulse.
  • the spring 18 acts between the members 8 and 12 to restore them to brake releasing condition.
  • the brake applying mechanism is hence not tripped by vibration occurring during operation of the saw or by normal manipulation of the saw such as occurs in use.
  • the guide bar moves in a direction away from the operator in a direction away from the operator does not actuate the brake.
  • the sustained acceleration as sensed by the inertial sensor results in quick and effective application of the brake.
  • the value of the inertial force required to trip the mechanism and apply the brake can be selected by adjusting or selecting the force exerted by the control spring 18.
  • a leaf spring 21 bears on the end portion of the brake band 5 to bias it toward the drum 4.
  • the force applied by the spring 21 assists in overcoming the inertia of the brake band 5 and the button 10 when the latter is disengaged by the operating member 8, thereby increasing the speed of application of the brake.
  • the slot in the guide plate 1 1 is long enough to avoid restricting inward movement of the end portion of the brake band.
  • the arm 8a is spaced from the button 10 to assure complete freedom of movement of the button 10.
  • the system comprising the operating member 8, control member 12 and spring 18 is bistable.
  • the line of action between the engaging surfaces of members 8 and 12 is to the left of the axis of member 12 so that the members stay in this position until a force is applied to move them.
  • the line of action is to the right of the axis of the member 12 and hence the members likewise remain in this position until a force is applied to return them to the position shown in FIG. 1.
  • control member 12 When it is desired to reset the chain saw for normal operation, the control member 12 is rotated in a clockwise direction by means of the guard member 15 from the position shown in FIG. 3to that shown in FIG. 1. The operating member 8 is thereby reset so as to release the brake.
  • FIG. 4 A modified construction is illustrated on FIG. 4 in which corresponding parts are designated by the same reference numerals.
  • a sleeve 25 pivotally connected to the operating member 8 by a pin 26 is provided with a blind bore 25a receiving the trailing end portion 50 of the brake band 5.
  • the bore 25a is of such depth that when the operating member 8 is in brake releasing position as shown in solid lines in FIG. 4, the sleeve 25 pushes on the end of the brake band 5 to expand the brake band and thereby free the clutch drum.
  • the operating member is in brake applying position as shown in broken lines in FIG. 4,
  • the bottom of the bore 25a of the sleeve 25 is spaced from the end of the brake band so that the brake band is free to contract to grip the drum.
  • a control spring acting between the operating member 8 and the control member 12 is shown as a torsion spring 28 having a helically wound portion 28a coaxial with the operating member '8.
  • One arm 28b of the control spring has an angularly bent portion received in a hole 8d of the operating member 8 while a second arm 28c has an angularly bent portion bearing on an edge .l2c of the control member 12.
  • the arm 28b of the control spring thus biases the operating member 8 in a clockwise direction while the arm 28c biases the con-- trol member 12 in a clockwise direction.
  • the line of action of the force exerted by the control spring is such that when the operating member 8 and the control member 12 are in set position as illustrated in solid lines in FIG.
  • the spring tends to hold them in set position.
  • the force exerted by the control spring is such that the operating member 8 and control member 12 are retained in set position despite vibration and normal movements occurring in the operation of the saw.
  • the inertial force acting through the inertial sensor comprising the guard member 15, control member 12 and the control spring 28 causes the operating member to rotate to the brake applying position illustrated in broken lines in FIG. 4.
  • the line of action of the force of the control spring 28 is such as to retain the members in this position.
  • the system comprising the operating member 8, control member 12 and control spring 28 is bistable. As described above, the system can be reset to brake releasing position by means of the guard member 15.
  • the brake band 5 instead of being of round or oval cross sectional shape can be of other crosssection which provides an area of engagement with the drum that will produce a braking pressure capable of penetrating any film of oil or other lubricant and provide a dry contact surface during braking. Still other modifications will occur to those skilled in the art.
  • a chain brake for. stopping the cutting chain of the chainsaw quickly, comprising a brake band engageable with said drum, means anchoring one end of said brake band, said band extending around said drum from said anchoring means in the direction of rotation of the drum, operatingmeans at the other end of said brake band and movable between a brake releasing position in which said operating means acts on said band to release the drum for rotation and a brake applying position in which .said brake band'engages'the drum and thereby applies a braking effect to the-drum, and inertial means operatively associated with said operating means and responsive to predetermined accelera tion of the chain saw to cause'movement of said operating means from brake releasing position to brake applying position and thereby apply a braking effect to the drum, said operating means comprising a first rotatable member having an abutment and operable to act on said other end of said brake
  • a chain brake in which said brake band comprises a spring band wrapped around said drum in a helical coil which in free condition has an inside diameter smaller than the outside diameter of the drum so that said spring band is inherently biased toward a condition in which it grips the drum, and in which said first rotatable member has a second abutment portion which acts on said other end of said spring brake band to move it in a direction opposite to the direction of rotation of said drum and thereby expand the helical coil of said band when said operating means is moved to brake releasing position.
  • a chain brake according to claim 1 in which said inertial means further comprises an eccentric mass connected to said second rotatable member and acting on said second rotatable member to rotate it upon predetermined sudden movement of the chain saw.
  • a chain brake according to claim 3 in which said eccentric mass comprises a handle portion for manual movement of said second rotatable member.
  • a chain brake according to claim 4 in which said second rotatable member is movable in one direction to move said operating means from brake applying to brake releasing position and is movable in the opposite direction to cause movement of said operating means from brake releasing position to brake applying position.
  • a chain brake according to claim 1, comprising means for manually rotating said second rotatable member in one direction to move said first mentioned rotatable member to brake releasing position and in the opposite direction for movement of said first mentioned rotatable member to brake applying position.
  • a chain brake according to claim 1, comprising means for calibrating said inertial means to determine the acceleration to which it is responsive upon sudden movement of the chain saw.
  • a chain brake for stopping the cutting chain of the chain saw quickly, comprising a flexible brake band wrapped more than one turn around said drum in a helical coil, means anchoring one end of said brake band, said brake band extending around said drum from said anhcoring means in the direction of rotation of the drum, operating means acting on the other end of said brake band alternatively to expand and to contract said helical coil of said brake band, said operating means being movable between a brake releasing condition in which the helical coil of said brake band is expanded so that the drum is free of said brake band and a brake applying condition in which the helical coil of said brake band is contracted to grip and thereby apply a braking action to said drum, inertial means operatively associated with and controlling said operating means, said inertial means being responsive to predetermined acceleration of the chain saw to cause movement of said operating means from brake releasing condition to brake applying condition and thereby apply a
  • a chain brake in which said operating means comprises a first rotatable member and said inertial means comprises a second rotatable member and a mass fixed relative to said rotatable member and disposed eccentrically thereof so as to be responsive to acceleration to rotate said second rotatable member upon said predetermined acceleration of the chain saw, said spring means comprising a spring action between said first and second rotatable members.
  • a chain brake in which said eccentric mass comprises handle means for manually rotating said rotatable member to move said operating means to brake released condition.
  • a chain brake in which the operative association between said inertial means and said operating means comprises integrating means responsive to the direction, magnitude and duration of forces acting on said inertial means. to cause movement of said operating means from brake releasing position to brake applying position only when said forces are of predetermined direction, magnitude and duration.

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  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • Braking Arrangements (AREA)
  • Sawing (AREA)
  • Supplying Of Containers To The Packaging Station (AREA)
  • Auxiliary Devices For And Details Of Packaging Control (AREA)
US483034A 1974-06-25 1974-06-25 Band type brake for a chain saw Expired - Lifetime US3923126A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
US483034A US3923126A (en) 1974-06-25 1974-06-25 Band type brake for a chain saw
SE7506970A SE426454B (sv) 1974-06-25 1975-06-17 Broms for en motorkedjesag
BR4895/75D BR7503806A (pt) 1974-06-25 1975-06-18 Freio inerte de corrente de acionamento manual
NO752209A NO143090C (no) 1974-06-25 1975-06-20 Anordning ved kjedesag.
DE2527812A DE2527812C2 (de) 1974-06-25 1975-06-21 Bremseinrichtung für eine Motorkettensäge
JP50075782A JPS5239199B2 (pt) 1974-06-25 1975-06-23
CA230,009A CA1027882A (en) 1974-06-25 1975-06-24 Inertial-manual actuating chain brake
GB2691475A GB1456014A (en) 1974-06-25 1975-06-25 Chain saw

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US483034A US3923126A (en) 1974-06-25 1974-06-25 Band type brake for a chain saw

Publications (1)

Publication Number Publication Date
US3923126A true US3923126A (en) 1975-12-02

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US483034A Expired - Lifetime US3923126A (en) 1974-06-25 1974-06-25 Band type brake for a chain saw

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US (1) US3923126A (pt)
JP (1) JPS5239199B2 (pt)
BR (1) BR7503806A (pt)
CA (1) CA1027882A (pt)
DE (1) DE2527812C2 (pt)
GB (1) GB1456014A (pt)
NO (1) NO143090C (pt)
SE (1) SE426454B (pt)

Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3974566A (en) * 1975-09-08 1976-08-17 Mcculloch Corporation Method and apparatus for arresting movement of a chain saw cutter chain
US4026392A (en) * 1974-10-15 1977-05-31 Mcculloch Corporation Snap-acting over-center chain saw safety brake and method of operation thereof
JPS5290897A (en) * 1976-01-22 1977-07-30 Stihl Andreas Braking device for use in motor driven hand saw especially power saw
FR2481986A1 (fr) * 1980-05-12 1981-11-13 Kioritz Corp Mecanisme de frein de surete pour scie a chaine mecanique
FR2537042A1 (fr) * 1982-12-03 1984-06-08 Stihl Andreas Scie a chaine
FR2548574A1 (fr) * 1983-07-08 1985-01-11 Stihl Andreas Dispositif de freinage pour chaine
US4493400A (en) * 1981-04-13 1985-01-15 Kioritz Corporation Emergency braking device for chain saw
US4586588A (en) * 1983-08-01 1986-05-06 Kioritz Corporation Chain saw safety-brake system
US4593796A (en) * 1982-05-11 1986-06-10 Emab Electrolux Motor Aktiebolag Brake operating device
EP0236749A2 (de) * 1986-03-14 1987-09-16 Robert Bosch Gmbh Einrichtung zum Schnellstopp und wieder Freigeben einer Sägekette
AU584617B2 (en) * 1984-05-23 1989-06-01 Stihl, Andreas Chain brake device
US5125160A (en) * 1991-05-15 1992-06-30 Textron Inc. Power tool inertia brake
EP0761398A1 (en) * 1995-09-04 1997-03-12 Makita Corporation A combination of a saw chain stopping and a brake drum stopping device for an electromotive chain saw
US5984054A (en) * 1996-10-25 1999-11-16 Aktiebolaget Electrolux Brake arrangement in a motor saw
DE19821697C2 (de) * 1997-05-16 2000-08-31 Kioritz Corp Bremsvorrichtung für eine motorangetriebene Arbeitsmaschine
US6588112B2 (en) * 1998-08-14 2003-07-08 Milwaukee Electric Tool Corporation Movable handle for a power tool
US20040181951A1 (en) * 2003-03-17 2004-09-23 Wittke Edward R. Chain saw safety system
US20050050690A1 (en) * 2003-03-19 2005-03-10 Remy Oddo Anti-vibratory handle for percussive and other reciprocating tools
US20050217124A1 (en) * 2002-12-30 2005-10-06 Wolfgang Fuchs Hand-held circular saw
US20070107165A1 (en) * 2003-03-19 2007-05-17 Remy Oddo Anti-vibratory handle for percussive and other reciprocating tools
EP2159018A1 (fr) * 2008-08-29 2010-03-03 PELLENC (Société Anonyme) Dispositif de sécurité pour outil portatifs à moteur thermique, permettant l'arret de leur fonctionnement, par suite de mouvements brusques et violents imprévus
US20100192391A1 (en) * 2006-10-19 2010-08-05 Atsushi Harada Brake system of chain saw and chain saw
US20100257743A1 (en) * 2009-04-08 2010-10-14 Rex George Systems and Methods for a Chainsaw Safety Device
US20100294098A1 (en) * 2009-05-21 2010-11-25 Yamabiko Corporation Work Apparatus With Safety Equipment
US20100294616A1 (en) * 2009-05-21 2010-11-25 Yamabiko Corporation Work Apparatus With Safety Equipment
US8061043B2 (en) 2006-11-15 2011-11-22 Milwaukee Electric Tool Corporation Power tool
WO2012021752A3 (en) * 2010-08-11 2012-05-24 Blount, Inc. Kickback detection method and apparatus
US20140141926A1 (en) * 2012-11-19 2014-05-22 GM Global Technology Operations LLC Transmission with band clutch
WO2019020164A1 (de) * 2017-07-24 2019-01-31 Festool Gmbh Elektrowerkzeug und verfahren zum erkennen eines kickback-ereignisses eines elektrowerkzeugs
WO2019020165A1 (de) 2017-07-24 2019-01-31 Festool Gmbh Elektrowerkzeug und verfahren zum erkennen eines ereignisses und/oder zustands eines elektrowerkzeugs
US10981267B2 (en) 2017-10-26 2021-04-20 Milwaukee Electric Tool Corporation Kickback control methods for power tools
US11529725B2 (en) 2017-10-20 2022-12-20 Milwaukee Electric Tool Corporation Power tool including electromagnetic clutch
US11697200B2 (en) 2017-07-24 2023-07-11 Festool Gmbh Power tool and method
US11705721B2 (en) 2020-03-10 2023-07-18 Milwaukee Electric Tool Corporation Kickback control methods for a power tool including a force sensor

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JPS5319892U (pt) * 1976-07-30 1978-02-20
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US4026392A (en) * 1974-10-15 1977-05-31 Mcculloch Corporation Snap-acting over-center chain saw safety brake and method of operation thereof
US3974566A (en) * 1975-09-08 1976-08-17 Mcculloch Corporation Method and apparatus for arresting movement of a chain saw cutter chain
JPS5290897A (en) * 1976-01-22 1977-07-30 Stihl Andreas Braking device for use in motor driven hand saw especially power saw
FR2338764A1 (fr) * 1976-01-22 1977-08-19 Stihl Andreas Dispositif de freinage pour scie portative a moteur, notamment pour scie a chaine a moteur
US4091896A (en) * 1976-01-22 1978-05-30 Firma Andreas Stihl Chain saw braking mechanism
US4328617A (en) * 1980-05-12 1982-05-11 Kioritz Corporation Safety brake mechanism for power chain saws
FR2481986A1 (fr) * 1980-05-12 1981-11-13 Kioritz Corp Mecanisme de frein de surete pour scie a chaine mecanique
US4493400A (en) * 1981-04-13 1985-01-15 Kioritz Corporation Emergency braking device for chain saw
US4593796A (en) * 1982-05-11 1986-06-10 Emab Electrolux Motor Aktiebolag Brake operating device
FR2537042A1 (fr) * 1982-12-03 1984-06-08 Stihl Andreas Scie a chaine
FR2548574A1 (fr) * 1983-07-08 1985-01-11 Stihl Andreas Dispositif de freinage pour chaine
US4594780A (en) * 1983-07-08 1986-06-17 Andreas Stihl Brake arrangement for a chain saw
US4586588A (en) * 1983-08-01 1986-05-06 Kioritz Corporation Chain saw safety-brake system
AU584617B2 (en) * 1984-05-23 1989-06-01 Stihl, Andreas Chain brake device
EP0236749A2 (de) * 1986-03-14 1987-09-16 Robert Bosch Gmbh Einrichtung zum Schnellstopp und wieder Freigeben einer Sägekette
EP0236749A3 (en) * 1986-03-14 1990-01-31 Robert Bosch Gmbh Instanteneous stopping device for arresting the movement of the saw chain of a portable motorized chain saw
US5125160A (en) * 1991-05-15 1992-06-30 Textron Inc. Power tool inertia brake
EP0761398A1 (en) * 1995-09-04 1997-03-12 Makita Corporation A combination of a saw chain stopping and a brake drum stopping device for an electromotive chain saw
US5791057A (en) * 1995-09-04 1998-08-11 Makita Corporation Electromotive chain saw
USRE37832E1 (en) * 1995-09-04 2002-09-10 Makita Corporation Electromotive chain saw
US5984054A (en) * 1996-10-25 1999-11-16 Aktiebolaget Electrolux Brake arrangement in a motor saw
DE19821697C2 (de) * 1997-05-16 2000-08-31 Kioritz Corp Bremsvorrichtung für eine motorangetriebene Arbeitsmaschine
US6588112B2 (en) * 1998-08-14 2003-07-08 Milwaukee Electric Tool Corporation Movable handle for a power tool
US20040003698A1 (en) * 1998-08-14 2004-01-08 Milwaukee Electric Tool Corporation Movable handle for a power tool
US7096588B2 (en) 1998-08-14 2006-08-29 Milwaukee Electric Tool Corporation Movable handle for a power tool
US7191526B2 (en) 1998-08-14 2007-03-20 Milwaukee Electric Tool Corporation Movable handle for a power tool
US7497152B2 (en) 1998-08-14 2009-03-03 Milwaukee Electric Tool Corporation Movable handle for a power tool
US7308764B2 (en) 1998-08-14 2007-12-18 Milwaukee Electric Tool Corporation Power tool with movable handle
US7975388B2 (en) * 2002-12-30 2011-07-12 Robert Bosch Gmbh Hand-held circular saw
US20050217124A1 (en) * 2002-12-30 2005-10-06 Wolfgang Fuchs Hand-held circular saw
US20040181951A1 (en) * 2003-03-17 2004-09-23 Wittke Edward R. Chain saw safety system
US7669290B2 (en) * 2003-03-19 2010-03-02 Universite De Sherbrooke Anti-vibratory handle for percussive and other reciprocating tools
US20070107165A1 (en) * 2003-03-19 2007-05-17 Remy Oddo Anti-vibratory handle for percussive and other reciprocating tools
US20050050690A1 (en) * 2003-03-19 2005-03-10 Remy Oddo Anti-vibratory handle for percussive and other reciprocating tools
US20100192391A1 (en) * 2006-10-19 2010-08-05 Atsushi Harada Brake system of chain saw and chain saw
US8176643B2 (en) * 2006-10-19 2012-05-15 Husqvarna Zenoah Co Ltd. Brake system of chain saw and chain saw
US8640346B2 (en) 2006-11-15 2014-02-04 Milwaukee Electric Tool Corporation Power tool
US8061043B2 (en) 2006-11-15 2011-11-22 Milwaukee Electric Tool Corporation Power tool
CN102137742B (zh) * 2008-08-29 2014-06-25 佩朗股份有限公司 用于具有热机的便携式工具的安全装置
EP2159018A1 (fr) * 2008-08-29 2010-03-03 PELLENC (Société Anonyme) Dispositif de sécurité pour outil portatifs à moteur thermique, permettant l'arret de leur fonctionnement, par suite de mouvements brusques et violents imprévus
FR2935496A1 (fr) * 2008-08-29 2010-03-05 Pellenc Sa Procede permettant l'arret des outils portatifs lors de mouvements brusques imprevus, et outils portatifs en faisant application
CN102137742A (zh) * 2008-08-29 2011-07-27 佩朗股份有限公司 用于带热机的便携式工具的安全装置，它能在突然急剧运动之后停止该便携式工具的操作
US20110186319A1 (en) * 2008-08-29 2011-08-04 Pellenc (Societe Anonyme) Safety device for portable tools with a heat engine, capable of stopping the operation thereof after sudden, violent movements
WO2010023377A1 (fr) * 2008-08-29 2010-03-04 Pellenc Sa Dispositif de securite pour outil portatifs a moteur thermique, permettant l'arret de leur fonctionnement, par suite de mouvements brusques et violents imprevus
US8579041B2 (en) 2008-08-29 2013-11-12 Pellenc (Societe Anonyme) Safety device for portable tools with a heat engine, capable of stopping the operation thereof after sudden, violent movements
US10071500B2 (en) 2009-04-08 2018-09-11 Rex George Safety system for a chainsaw
US20100257743A1 (en) * 2009-04-08 2010-10-14 Rex George Systems and Methods for a Chainsaw Safety Device
US8752301B2 (en) * 2009-04-08 2014-06-17 Rex George Chainsaw incorporating a safety device system
US20100294098A1 (en) * 2009-05-21 2010-11-25 Yamabiko Corporation Work Apparatus With Safety Equipment
US20100294616A1 (en) * 2009-05-21 2010-11-25 Yamabiko Corporation Work Apparatus With Safety Equipment
US9769985B2 (en) * 2009-05-21 2017-09-26 Yamabiko Corporation Work apparatus with safety equipment
US9769984B2 (en) * 2009-05-21 2017-09-26 Yamabiko Corporation Work apparatus with safety equipment
CN103068537A (zh) * 2010-08-11 2013-04-24 布楼恩特公司 回踢检测方法和装置
WO2012021752A3 (en) * 2010-08-11 2012-05-24 Blount, Inc. Kickback detection method and apparatus
US20140141926A1 (en) * 2012-11-19 2014-05-22 GM Global Technology Operations LLC Transmission with band clutch
US8870703B2 (en) * 2012-11-19 2014-10-28 Gm Global Technology Operations, Llc Transmission with band clutch
US11697200B2 (en) 2017-07-24 2023-07-11 Festool Gmbh Power tool and method
WO2019020165A1 (de) 2017-07-24 2019-01-31 Festool Gmbh Elektrowerkzeug und verfahren zum erkennen eines ereignisses und/oder zustands eines elektrowerkzeugs
US11491564B2 (en) 2017-07-24 2022-11-08 Festool Gmbh Power tool, system, and method
WO2019020164A1 (de) * 2017-07-24 2019-01-31 Festool Gmbh Elektrowerkzeug und verfahren zum erkennen eines kickback-ereignisses eines elektrowerkzeugs
US11701723B2 (en) 2017-07-24 2023-07-18 Festool Gmbh Power tool, system, and method
US11529725B2 (en) 2017-10-20 2022-12-20 Milwaukee Electric Tool Corporation Power tool including electromagnetic clutch
US10981267B2 (en) 2017-10-26 2021-04-20 Milwaukee Electric Tool Corporation Kickback control methods for power tools
US11607790B2 (en) 2017-10-26 2023-03-21 Milwaukee Electric Tool Corporation Kickback control methods for power tools
US11648655B2 (en) 2017-10-26 2023-05-16 Milwaukee Electric Tool Corporation Kickback control methods for power tools
US11705721B2 (en) 2020-03-10 2023-07-18 Milwaukee Electric Tool Corporation Kickback control methods for a power tool including a force sensor

Also Published As

Publication number Publication date
DE2527812C2 (de) 1986-02-20
CA1027882A (en) 1978-03-14
JPS5117097A (pt) 1976-02-10
DE2527812A1 (de) 1976-01-15
GB1456014A (en) 1976-11-17
SE7506970L (sv) 1975-12-29
BR7503806A (pt) 1976-07-06
NO143090B (no) 1980-09-08
NO143090C (no) 1980-12-17
NO752209L (pt) 1975-12-30
SE426454B (sv) 1983-01-24
JPS5239199B2 (pt) 1977-10-04

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