Internal-combustion engines – Starting device – Mechanical
Reexamination Certificate
2001-12-17
2004-02-24
Vo, Hieu T. (Department: 3747)
Internal-combustion engines
Starting device
Mechanical
C123S185300, C185S0410WW
Reexamination Certificate
active
06694941
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a recoil starter which is adapted for use in an internal combustion engine, and in particular, to a recoil starter provided with a buffering/power-accumulating means which is interposed between a driving member comprising a rope reel which is designed to be rotated by the pulling of a recoil rope, and a driven member to which the torque of the driving member is transmitted.
A conventional recoil starter which is designed to be mounted on an internal combustion engine is generally provided with a driving member comprising a rope reel around which a recoil rope is wound, and a driven (idler) member comprising a centrifugal ratchet mechanism. When the internal combustion engine is desired to be started, the recoil rope (recoil handle) is pulled to revolve the rope reel, the resultant revolution of the rope reel being then transmitted, via the driven member, to a crankshaft of the internal combustion engine to thereby start the internal combustion engine.
As set forth in Japanese Patent Application No. H11-238642, the present inventors have previously proposed a modification of the aforementioned recoil starter, wherein a spiral spring mechanism is interposed, as the buffering/power-accumulating means, between the driving member and the driven member.
According to this modified recoil starter, since the spiral spring mechanism is interposed, as the buffering/power-accumulating means, between the driving member and the driven member, it is possible to derive a buffering effect from the spiral spring mechanism during the first-half driving process (until the piston of the internal combustion engine reaches to the top dead center thereof) in the pulling operation of the recoil rope (recoiling operation), and at the same time, to enable the pulling force of the recoil rope to be accumulated in the spiral spring mechanism. During the latter-half driving process, the pulling force thus accumulated in the spiral spring mechanism during the first-half driving process is permitted to be combined with the pulling force to be actually effected in the latter-half pulling operation of the recoil rope to thereby generate a resultant force, which is utilized as a force for starting the internal combustion engine.
As a result, it is possible to minimize a fluctuation in pulling force of rope so as to smooth the rope-pulling operation, thus enabling even a person having a weak physical strength to easily start the internal combustion engine.
However, this modified recoil starter previously proposed by the present inventors is accompanied with the following possible problems.
Namely, since this modified recoil starter is designed such that the spiral spring of the spiral spring mechanism is rewound so as to accumulate the pulling force during the first-half driving process in the pulling operation of the recoil rope (recoiling operation), that during the latter-half driving process, the pulling force thus accumulated during the first-half driving process is released, thus unwinding the spiral spring and enabling the spiral spring to be restored to the original released state thereof, while permitting the spiral spring mechanism to rotate in the direction to drive the crankshaft, and that after the start-up of the internal combustion engine, the interlocking engagement between the spiral spring mechanism and the internal combustion engine is permitted to be released due to the releasing action by the centrifugal ratchet mechanism attached to the driven member, thus rendering the spiral spring mechanism to become free, the spiral spring is permitted, due to the inertia of the releasing movement of the spiral spring, to be excessively kicked back in the unwinding direction (releasing direction) even after the spiral spring has taken the fully unwound and released state thereof.
Generally, a spiral spring is usually employed, as in the case of a watch, under the conditions where the spiral spring is completely wound up and is then incompletely unwound leaving one or two unreleased turns. In the case of the aforementioned recoil starter however, since the spiral spring mechanism is rendered free after the start-up of the internal combustion engine, the spiral spring is completely released without leaving even a single unreleased turn, and is still more permitted to be excessively kicked back in the unwinding direction. Namely, the spiral spring is not used in a manner which the spiral spring is inherently intended to.
Therefore, the innermost end region of the spiral spring is repeatedly and locally subjected to a winding/unwinding stress, thus giving rise to the generation of settling and bending at this innermost end region of the spiral spring. As a result, not only the durability of the spiral spring is badly affected, but also the internal hook end of the spiral spring which is fastened to the core portion of the actuating pulley of spiral spring mechanism tends to be disengaged from the core portion, thereby raising a possibility that the rope-pulling manipulation may result in a futile try.
The present invention has been made in view of the aforementioned problems, and therefore, it is an object of the present invention to provide a recoil starter having a spiral spring mechanism interposed, as a buffering/power-accumulating means, between a driving member comprising a rope reel which is designed to be rotated by the pulling of a recoil rope, and a driven member to which the torque of the driving member is transmitted, the recoil starter being characterized in that it is capable of inhibiting the generation of settling and bending in the spiral spring of the spiral spring mechanism, thereby making it possible not only to improve the durability of the spiral spring, but also to prevent the internal hook end of the spiral spring from being easily disengaged from the core portion of the actuating pulley of spiral spring mechanism. Another object of the present invention is to provide a spiral spring which is excellent in durability and therefore is suited for use in the recoil starter, etc.
BRIEF SUMMARY OF THE INVENTION
With a view to attaining the aforementioned object, there is provided, in accordance with the present invention, a recoil starter which fundamentally comprises a driving member having a rope reel around which a recoil rope is wound to thereby enable the rope reel to be rotated by pulling the recoil rope, a driven (idler) member to which the torque of the driving member is transmitted, and a buffering/power-accumulating means interdisposed between the driving member and the driven member; wherein the buffering/power-accumulating means is enabled, during the driving process by the driving member, to accumulate the power supplied through the driving process while alleviating any impact to the driven member, the accumulated power being subsequently employed to drive the driven member, and wherein the spiral spring mechanism is rendered free after the start-up of an internal combustion engine.
In this case, the spiral spring mechanism is featured in that it comprises a spiral spring case placed close to the driving member, a actuating pulley placed close to the driven member, a spiral spring interposed between the spiral spring case and the actuating pulley, and means for rotating the spiral spring case only unidirectionally, wherein an outer end portion of the spiral spring and an inner end portion of the spiral spring are fastened to the spiral spring case and the actuating pulley, respectively.
In a preferable embodiment of the present invention, the spiral spring of the spiral spring mechanism comprises an outer circumferential wound portion where a predetermined number of turns of the outer circumferentially wound portion of the spiral spring are closely contacted with each other under a freely released condition of the spiral spring, and an inner circumferential wound portion which is constituted by at least one turn of the inner circumferentially wound portion of the spiral spring, wherein a clearance is provided betwee
Akaike Junichi
Iida Kazumasa
Kishida Shingo
Taomo Toshio
Ueda Tamotsu
Baker & Botts LLP
Castro Arnold
Kioritz & Corporation
Vo Hieu T.
LandOfFree
Starter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Starter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Starter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3319930