Dentistry – Apparatus – Having condition sensor to transmit signal to regulate...
Reexamination Certificate
2000-06-05
2002-03-19
Lucchesi, Nicholas D. (Department: 3732)
Dentistry
Apparatus
Having condition sensor to transmit signal to regulate...
Reexamination Certificate
active
06358048
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a ‘Pinch Valve’ assembly whose design has not before been presented in this format WITHIN A HANDPIECE HOLDER ASSEMBLY for controlling the delivery of any gas, air and/or water to Medical, Dental, laboratory or other types of delivery systems, but may be used in other Industries where this application could apply.
2. Description of the Prior Art
Conventional Medical, Dental and Laboratory drills are operated at relatively high speeds by an Air Turbine driven from a source of pneumatic air flow at a regulated pressure. These pressures and corresponding flows are controlled by centrally located ON/OFF pre-machined Control Blocks, with internal valving which forms the main functions of the systems. Worldwide these systems use one of the following technologies.
Technology (1) totally pneumatic:
This involves the used of Plungers, Springs, Diaphragms, and various forms of ‘O’Rings and other associated interface moving part components preassembled inside. Control Blocks carefully machined internally to close tolerances working in conjunction with secondary air circuits through independent multiple handpiece holder switches, again using the same basic design in miniature form having a plunger with ‘O’Rings and a tension spring inserted at the back of each holder; when the tool or handpiece is pushed into the holder, the Instrument hose coupling would actuate the valve by pressing against the plunger thereby creating the OFF state. Withdrawal of the tool or handpiece opens the valve sending an air pressure signal to the Control Block. This signal pressure forces down the internal diaphragm and piston to an open or ON state allowing air flow to commence actuation of the tool or handpiece.
Technology (2) Electro-pneumatic:
These systems involve the use of Electro-pneumatic Solenoid Valves and/or Logic Valves, working in sequence with low voltage signals from micro-switches located at the rear of the handpiece holders. As the tools or handpieces are removed and replace into the holders by the operator, the micro-switches are ‘tripped’ to actuate the Solenoid Valves in an ON and OFF function of the Air and/or Water flow to the tool or handpiece.
Technology (3) Fluidic Controlled Blocks:
A control arrangement developed by applicant uses a modular pre-machined Fluidic Block design, described in U.S. Pat. No. 4,069,587 dated Jan. 24, 1978 accomplished multiple handpiece switching functions.
Although this Block, with its handpiece holder positions built into it formed a compact way to distribute several airflow circuits, it is operationally dependent upon the accuracy in alignment of a laminar flow of air bridging an air gap across the internal walls of the holder. When the tool or handpiece is removed from the holder, the Laminar air flows across the gap, enters the adjacent aperature and signals the Fluidic device to the ON state.
This design required precise machining operations and expensive to manufacture.
A further improvement to this design for simplicity was carried out in February, 1989 in the form of a Cassette for controlling the supply of air and/or water to a Dental or Laboratory tool or handpiece, as described under U.S. Pat. No. 4,806,099. While simplicity in function was achieved the fabrication of an expensive mold, with inner chambers and involving the use of a Diaphragm, a Plunger and ‘O’Rings, made the assembly time consuming with detailed ‘Quality Control’ checks which did little to reduce production costs. To simplify the ON/OFF function of this Cassette design, original pneumatic handpiece holder switches as used in totally pneumatic systems: Technology (1) are employed for the selection of the tools or handpieces.
Technical Clarification to Technologies (1) and (2):
In both of these two systems a secondary Air or Electronic circuit is need to activate the ON/OFF Control Blocks or Solenoid Valves when the tool or handpiece is removed from its holder.
Commencement of a ‘Break-Through’ in Simplification
The Medical, Dental and Laboratory industries began recognizing the fact that simpler Delivery systems circuitry were essential to progress, and that pneumatics held the key began employing the ‘Pinch Valve’ principle.
The two Dental Equipment Manufacturers who spearheaded this move some 17 years ago to try and simplify designs by using the ‘Pinch Valve’ technique were Proma of California and Ritter of Germany. This was achieved in two forms:
1) Passing flexible vinyl tubing through a Control Block where it is ‘pinched flat’ by an internal, spring loaded Piston whose ON/OFF action is dependent on the flow of pressurized air being discharged from the Foot Control AND the tool or handpiece being removed from a holder, as described in Technology (
1
a
).
No Basic Change
Although the machining of the Control Block was simplified, the Circuit itself still required a secondary Air Circuit in order to function.
2) The Proma Company struggled to break away from this form of basic circuitry by introducing a form of ‘Pinch Valve’ technique whereby the flexible vinyl tubing was passed between solid, round rollers connected to outstretched, metal arms. At the end of the arms, one for each tool or handpiece were positioned the handpiece holders. When the tool or handpiece is removed from the holder AND the operator, physically pushes UPWARD on the arm, this releases the tension or ‘pinching action’ on the tube being pinched flat by the roller and the Drive Air commences to flow, when the Foot Control is depressed by the operator.
At this Point: (as the date of this Patent Application)
No known further advancements have been manufactured and sold, to change and/or improve on these types of ‘pinching’ devices.
A substantial need has developed for a far more simplified Control Delivery system, which totally eliminates the use of the following:
1) Pneumatic Control Blocks whose function depends on the internal actuation of Diaphragms, Plungers, and Springs.
2) Logic Valves using precisely machined or molder interface moving parts.
3) Distribution Manifolds with their maze of tubing circuitry.
4) Manually operated selector components commonly termed ‘Routing Valves’.
5) Solenoid Valves with their electronic circuit boards and associated components.
While concentrating on the elimination of these components to also build into place a truly simplified circuitry requiring NO EXTENSIVE ‘time consuming’ Quality Control work while being assembled at the factory or ‘ON SITE’.
This control delivery system is designed to arrive at the end user preassembled, ready, ready to be used and requires no special training to ‘link up’ the two standard air and water supply couplings.
Note
Fluidic: A term used as the science of using very low pressures below 0.007 p.s.i. in accomplishing control functions of excessively high air pressures, Water, Hydraulics or in combination with Electronics, not easily obtainable by other mediums.
SUMMARY OF THE INVENTION
It is the principal object of the Patent Application presented to further clarify and consolidate the previous documentation dated May 11, 1999, Ser. No. 60/133,658, and to describe more fully this distinct ‘Pinch Valve’ embodiment along with its simplified associated circuitry, specially designed for its function, ease of manufacture and trouble free daily use.
These and other objects are attained in accordance with this designed method of a ‘Pinch Valve’ system not before presented into the Medical, Dental and Laboratory industries, although may also apply to other industries where this application applies.
It is the further principal object of the present invention to describe the specific manner or method by which the flexible Drive Air tube (vinyl or other material) is ‘pressed/pinched flat’ INSIDE THE ACTUAL HANDPIECE HOLDER ASSEMBLY itself, thereby totally eliminating the passage of tubing through a Control Block, prior to the handpiece holder, and as a result dispenses with the need for any form of Control Block or associated tubing Distribution Manifold. This design form
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