Electrical transmission or interconnection systems – Personnel safety or limit control features
Reexamination Certificate
2001-03-26
2004-01-06
Toatley, Jr., Gregory J. (Department: 2836)
Electrical transmission or interconnection systems
Personnel safety or limit control features
C123S179500
Reexamination Certificate
active
06674184
ABSTRACT:
TECHNICAL FIELD
The invention concerns a stop device for a gasoline motor powered, hand-operated working machine, which is stopped by short-circuiting an electric circuit, said stop device being designed in the form of en electric switch comprising a stop control, which can be moved manually between two end positions; a drive position for start of the motor and for motion of the motor, in which drive position said circuit is not short-circuited, and a fixed stop position in which the circuit is short-circuited and the stop control is locked.
The invention also concerns the gasoline motor powered, hand-operated working machine which is provided with the stop device.
BACKGROUND OF THE INVENTION
According to current safety regulations, the stop control of gasoline motor powered, hand-operated working machines must have a fixed stop position, which shall be possible to be adopted therein that the operator moves the stop control from the drive position to the fixed stop position through a single, uninterrupted movement. The reason for this regulation is that the machine safely shall be able to be stopped in an emergency situation. But also in case of occasional stops, e.g. for periods of rest, refuelling etc., the stop control of existing machines need to be moved to the fixed end stop in order to stop the motor. Before the machine can be restarted, the stop control must be brought back to the drive position. It frequently happens that the operator forgets to do that and repeatedly pulls the starter rope until he becomes aware of his mistake, and this is particularly true when existing stop controls have the shape of a knob or slide which does not provide any readily visible signals. Meanwhile the engine often has become “wet”, which makes the start difficult.
BRIEF DISCLOSURE OF THE INVENTION
It is the purpose of the invention to address the above mentioned problem. According to a first aspect of the invention, which concerns the stop device which is first mentioned in the preamble, the invention is characterised in that the electric circuit is short-circuited also in a non-locked intermediate position of the stop control, which the stop control must pass, if it is brought all the way from the drive position to the fixed stop position, and that a spring is provided to return the stop control to the drive position, if the stop control is moved from the drive position to said intermediate position and then released, implying that the intermediate position is a re-springing stop position of the stop control. According to this aspect of the invention, the operator thus can choose either to move the stop control from the drive position beyond the intermediate position and further on to the fixed stop position, a possibility which can be used in emergency situations, or e.g. when the job has been finished for the day, or to move the stop control only to the intermediate position so that the machine is stopped by short-circuiting the electric circuit, whereafter the stop control is released and is automatically caused to spring back to the drive position. In the latter case, the operator need not think of positioning the stop control in a proper position before start.
According to another aspect of the invention, the stop device is characterised in that it is designed as a toggle switch including a rocker which is turnable about an axis of rotation, that the rocker has a first, outer lever with a grip member and a second, inner lever, that the rocker is biased by the force of the spring which acts against said inner lever, and that the movable contact member is provided to be conveyed by the inner lever as the rocker is being turned against said re-springing and/or fixed position of contact.
According to still another aspect of the invention, the stop device is characterised therein that it is designed as a toggle switch, said stop control forming a rocker, which includes a first lever which is turnable about an axis of rotation between said drive position and said fixed stop position, that said first lever is substantially turned into a wall of the working machine in the drive position of the machine, when the stop device is mounted on a working machine, and that it in the fixed drive position substantially is turned out from said wall. According to this aspect of the invention, the turned out lever including the grip member in the fixed stop position acts as a readily observable signal to the operator that the stop device has adopted its fixed stop position and that the machine therefore cannot be started. This signal is enhanced if the stop control including the grip member has a bright signal-colour. The turned out position of the stop control in other words gives the operator an impulse to turn in the control with said outer lever as an initial measurement before start.
According to yet another aspect of the invention, which relates to the gasoline motor powered, hand-operated working machine, the working machine is of the well known type which includes a rear operating handle with a starter throttle control on one side of the operating handle, which starter throttle control must be pressed into the operating handle before start. The characteristic features of the invention according to this aspect of the invention are that the stop device is designed as a toggle switch on a wall of the machine at the side of the starter throttle control and that a first, outer lever of a rocker of the toggle switch, in the fixed stop position, is substantially turned out from the wall of the machine at the side of the operating handle in a direction towards the starter throttle control to a position outside of the starter throttle control, such that the starter throttle control is made difficult to access by the machine operator, while said lever in the drive position is turned away from the starter throttle control and substantially into said wall, such that the starter throttle control is made easy to access and the rocker is protected, so that the engine is not unintentionally switched off during operation.
Said aspects of the invention can be combined with one another but in some respects be employed independent of each other.
Further aspects and characteristic features of the invention will be apparent from the appending patent claims and from the following detailed description of the invention.
REFERENCES:
patent: 3851126 (1974-11-01), Keller
patent: 4919091 (1990-04-01), Wissmann et al.
patent: 5209196 (1993-05-01), Nickel et al.
patent: 5485814 (1996-01-01), Tuggle et al.
patent: 38 21 958 (1990-01-01), None
Donnerdal Ove
Söderqvist Magnus
Aktiebolaget Electrolux (publ)
Bednarek Michael D.
Shaw Pittman LLP
Toatley , Jr. Gregory J.
LandOfFree
Stop device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stop device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stop device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3233170