Power plants – Pressure fluid source and motor – Pneumatic motor with gas supply or removal device
Reexamination Certificate
1998-10-01
2001-08-28
Lopez, F. Daniel (Department: 3745)
Power plants
Pressure fluid source and motor
Pneumatic motor with gas supply or removal device
C092S134000
Reexamination Certificate
active
06279315
ABSTRACT:
The present invention generally relates to a pneumatic piston-cylinder apparatus which is useful for many different purposes where it is desired to provide a reciprocating movement, especially a movement having a soft braking phase at each end position, and the invention is more particularly directed to such an apparatus which saves air power, is operating silently and is capable of operating during a certain period of failure of electric power. A special embodiment of the invention is arranged so as to operate with a substantially closed air system.
The invention has been developed especially as the solution of the problem to provide a quick, safe, effective and cheap apparatus for unlocking and closing of doors, both swinging doors and sliding doors. Special advantages are reached for double sliding doors operating in opposite directions, whereby is meant the type of doors which open in that two door halves are moved sideways apart in opposite directions, and which close in that said door halves are moved sideways towards each other.
In the following the invention will mainly be described in connection to such an application, but it is to be understood that this is not intended to restrict the invention or the field of use of the invention.
Known door unlockers of automatically unlocking type include electrically, hydraulically and pneumatically operating door unlockers, and such door unlockers are generally formed so as to open when a person or an object enters a predetermined scanning field, and to close after the lapse of a predetermined period of time. The present invention is, however, as well useful for the type of doors which open after a button has been pressed. This type of door unlockers are generally formed with some type of jam protection means which makes the door become re-opened if there is some obstacle remaining between the doors when the door starts closing.
Both electric and hydraulic door unlockers of the said type often have a heavy unlocking and closing function, and therefore persons and objects may be hurt or damaged if the jam protection means for some reason should fail, or if there should be any obstacle at some part of the door which has no jam protection means, for instance a door part adjacent the upper edge or the bottom edge of the door. Both types of door unlockers therefore often have to be formed with special control means for varying both the speed and the force of the door movement over the unlocking distance. Such control means makes the known products expensive in manufacture.
In many cases there is used oil filled gears and similar control means for the door unlockers, and this may lead to soiling depending on waste of oil and the existense of oil also may create problems in case of fire, since the oil is inflammable.
Also pneumatic door unlockers, which are in many cases directly operating, give rise to the same problems as electric and hydraulic door unlockers in the sense that they may have great unlocking speeds and great forces of movement, and they sometimes present slamming and hitting noises when the doors stop at their end positions.
Many known door unlockers also are formed so that at least the unlocking function is ceased in case of failure of electric current, whereby the doors remain in their closed and locked positions. In order to make it possible to open the doors in case of fire, considering the fact that fire often leads to failure of current, said doors must be formed with some type of releasing means which can be actuated in case of emergency. In many cases it is necessary to call for an operator for disconnecting the releasing means and this may delay the opening of the doors. Generally such emergency release means are formed so that the doors remain in their open condition after the emergency release means has been actuated, and this may lead to the disadvantage that air is introduced to a fire centre, and this may intensify the fire.
The basis of the invention therefore has been the problem or providing a pneumatic apparatus for reciprocatory actuation of one or more objects, like doors, which apparatus
is simple, effective and cheap to manufacture,
provides a quick starting movement and a decelerated end movement, preferably in both directions of movement,
provides a braking of the speed and a successive reduction of the moment force during at least the last half of the total operation distance,
automatically closes the doors in case of failure of electric current,
but in which case the doors can easily be opened by the force of one's hands and without the need of using tools,
makes it possible to reclose the doors several times even during periods of failure of electric current,
may extremely simply be emergency released so that for instance the doors remain open,
operates very silently,
operates economically by using a substantially closed air system,
provides a quick unlocking and a slow and soft closing of the doors,
operates with a remarkably low and substantially safe air pressure,
gives a great fire safety in combination with full possibility for persons to enter and to leave through doors even at failure of electric current, and other advantages.
According to the invention the pneumatic apparatus, which can be used as an unlocking and closing apparatus, is formed with a pneumatic piston-cylinder unit operating with a substantially closed air system, and in which full force, in the following referred to as operating force, is created in one direction, for instance in the unlocking (opening) direction, and in which the return movement (closing) is made using a substantially less air pressure than the full force pressure, in the following referred to as return force, and in which both the full force movement, or operation movement, and the return movement follows against a counter pressure in the opposite piston chamber of the piston-cylinder unit. Further characteristics and advantages of the invention will be evident from the following detailed specification in which reference will be made to the accompanying drawings.
REFERENCES:
patent: 913853 (1909-03-01), Rowntree
patent: 2475701 (1949-07-01), Eaton
patent: 2820434 (1958-01-01), Otto
patent: 3613503 (1971-10-01), Phillips
patent: 4152870 (1979-05-01), Knap
patent: 0654608 (1994-11-01), None
patent: 1317651 (1973-05-01), None
patent: 1428996 (1976-03-01), None
patent: 1428994 (1976-03-01), None
Larson & Taylor PLC
Lopez F. Daniel
Safe Net i Harads AB
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