AU595694B2

AU595694B2 - Pneumatic door operator

Info

Publication number: AU595694B2
Application number: AU13352/88A
Authority: AU
Inventors: Anthony G. Aquilina
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-03-24
Filing date: 1988-03-22
Publication date: 1990-04-05
Anticipated expiration: 2008-03-22
Also published as: EP0284192A3; DE3874379T2; EP0284192B1; CA1326245C; ATE80438T1; DE3874379D1; AU1335288A; EP0284192A2

Abstract

A door operator system includes a fluid cylinder (10) that has a cylinder body (12) and a rodless piston (30) adapted for reciprocation in the cylinder body (12). A carriage (50) which is adapted for reciprocation externally along the length of the cylinder body (12) is secured to the piston (30). An arm member (70) connects the cylinder carriage (50) to an associated sliding door. A control circuit is provided for controlling the operation of the fluid cylinder (10) and hence the position of the associated sliding door.

Description

II~rYU II- 595694 S F Ref: 51907 FORM COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION gi" i

(ORIGINAL)

Class Int Class FOR OFFICE USE: p r.

4* *i 0 Complete Specification Lodged: Accepted: Published: Priority: Related Art: Name and Address of Applicant: Anthony G Aquilina R.R. 5 Milton Ontario L9T 2X9

CANADA

Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Address for Service: P 4 p 0r Complete Specification for the invention entitled: Pneumatic Door Operator The following statement Is a full description of this invention, including the best method of performing it known to me/us 5845/3 PNEUMATIC DOOR OPERATOR BackgLoun of the Invention This invention generally pertains to a pneumatic door operator construction. More specifically, the present invention relates to a sliding door operator system which utilizes a rodless fluid cylinder for mechanically opening and closing a door.

The invention is particularly applicable to sectional overhead doors of the mul tiple panel type and will be described with particular reference thereto.

However, it will be appreciated by those skilled in the art that the invention has broader applications and may also be adapted for use in many other environments such as single panel overhead doors and even sideward sliding doors or thle like.

:Most overhead doors are counterbalanced with a torsion spring or a counterweight system for storing energy during door closing so that energy may be extracted during door opening. During opening, most of the energy for lifting such a ori ervdfo th e energy stored in the spring or counterweight system. If the door is counterbalanced fairly well, the amount of manual energy required to open the door need only be sufficient to makc up the frictional and other losses in thle sys tem. During door closing, tile energy required is that for making up the frictional and other losses since most of thle energy which is transferred to the spring or counterweight storage system is derived from thle weight of the descending door.

In general, conventional overhead doors of this nature are actuated by a cable which is wound around a ~d 30 drum axially driven by the torsion spring with thle drum -2 being rotated by a chain driven sprocket. Generally, the chain is driven by an electric motor. In some environments, however, the use of electrical motors is undesirable because of the possible danger of a spark causing an explosion or a fire. It has also been found that electric motors are disadvantageous since if the door becomes jammed the motor will continue rotating and will likely unwind the cable between the drum and the door and this could prove hazardous to personnel and may damage property.

Also, when such door's go through a high number of cycles, such as in a car wash or the like, the chains, sprockets, electrical motors, and bearings wear out at a fairly rapid rate and this results in frequent breakdowns of the door opening mechanism. Moreover, malfunctions of the door opening mechanism sometimes also lead to damage to the upper portion of the door which can be fairly expensive to repair.

One recent suggestion has been to utilize a pair of pneumatic cylinders in a side mounted operator for moving the chain of the chain driven sprocket thereby rotating the sprocket. However, side mounted operators are not recommended when a trolley operator could be used in their place since with a side mounted operator any hesitation in the door travel results in an unwinding of the cable from the torsion bar drum which Smakes the door liable to a free fall that could cause grave injury to people as well as damage to objects under the door and to the door itself. The pneumatic 3 cylinder actuated side mounted operator mechanism is also disadvantageous since chains and sprockets which undergo a high number of cycles wear out at a relatively rapid rate resulting in frequent breakdowns of the door operator mechanism and, sometimes, damage to the door.

tl 3 Accordingly, it has been considered desirable to develop a new and improved door operator system which would overcome the foregoing difficulties and others while providing better and more advantage us overall results.

Brief Summary of the Invention In accordance with the present invention, a new and improved sliding door operator system is provided.

More particularly in accordance with this aspect of the invention, the system comprises a rodless fluid cylinder including a cylinder body and a rodless piston adapted for reciprocation in the cylinder body.

1. A carriage is adapted for reciprocation -xternallv along the length of the c4l4in- body with the carriage being secured to the piston. An arm means is provided for connecting the cylinder carriage to an associated sliding door.. A control means is provided for controlling the operation of the fluid cylinder and hence the position of the associated sliding door.

c prep-re& IIn accordance wi th -a.n444-o aspect of the invention, the system further comprises a bracket moans i for securing the fluid cylinder to an adjacent wall.

2 In accordance with still another/aspect of the invention, the system further comprises a switch means located at each end of the cylinder with the switch means being in electrical contact with the control means to activate associated electrical equipment.

preerr S. In accordance with yet anotherlaspect of the Sinvention, the arm means comprises a pair of telescoping tubular sections with the first of the sections being secured to the fluid cylinder carriage and a second of S16 The system of claim 4 further comprising a first pivot means for pivotally securing said first ~1_1 IIY 4 the sections being secured to the associated sliding door. The arm means further comprises a resilient means for cushioning the telescoping action of the pair of tubular sections. Preferably, a first pivot means is provided for pivotally securing the first section to the fluid cylinder carriage and a second pivot means is provided for pivotally securing the second section to the associated sliding door.

In accordance with yet still another aspect of the invention, the control means comprises a source of pressurized fluid and a conduit means for connecting the source of pressurized fluid to the fluid cylinder. A control panel is also provided for controlling the flow of pressurized fluid through the conduit means.

Preferre& In accordance with a furtherkaspect of the invention, the source of pressurized fluid is in fluid communication with both ends of the fluid cylinder so that it can act on either end of the rodless piston.

S" Preferably, the cylinder is provided with seal means for preventing the pressurized fluid from flowing out of the cylinder. Preferably, both ends of the fluid cylinder also include an adjustable valve means communicating with the environment.

According to a further aspect of the invention, an air powered sliding door operator system is provided.

1: aerrecX SAccording to thisl aspect of the invention, the system comprises a door which is mounted for sliding movement between a first position in which it closes a S building opening and a second position away from the opening. The system also includes a rodless air cylinder which comprises a cylinder body, a rodless piston adapted for reciprocation in the cylinder body and a carriage adapted for reciprocation externally along the length of the cylinder body with the carriage '1 \YJ U i 5 being secured to the piston. A shock absorbing connecting means is provided for securing the cylinder carriage to the sliding door. A valve means is provided for selectively feeding pressurized air to the air cylinder to drive the rodless piston and hence the carriage thereby moving the door between the first and second positions thereof.

In accordance with yet another, aspect of the invention, an air powered operator system is provided for an articulated overhead sliding door that is movable in guide ways which extend upwardly alongside an opening for the door and then rearwardly.

More specifically in accordance with this preFerreaspect of the invention, the system comprises an air cylinder that includes an elongated cylinder body and a rodless piston adapted for longitudinal reciprocation in the cylinder body. The cylinder also comprises a carriage adapted for reciprocation externally along the S* length of the cylinder body with the carriage being r secured to the piston. The system further comprises an L-shaped arm member, which connects the cylinder carriage to the door, and a source of pressurized air which is in fluid communication with the air cylinder.

A valve means is interposed between the source of pressurized fluid and the air cylinder for selectively feeding pressurised air to the air cylinder to reciprocate the rodless piston therein.

One advantage of the present invention is the provision of a new door operator system for sliding 'i doors.

Another advantage of the present invention is the provision of a door operator system which actuate a door by the movement of a rodless piston which reciprocates in a cylinder.

/CY'

rn

'A

'I

rr, -6 Still another advantage of the present invention is the provision of a door operator system which can actuate most types overhead doors that have a counterbalance means and can also actuate selected sideward sliding doors.

Yet another advantage of the present invention is the provision of a trolley-type door operator system which does away with chains, sprockets, bearings, and motors, all of which are prone to frequent breakdowns when exposed to high numbers of cycles.

A further advantage of the present invention is the provision of a door operator system which opens and closes a door with a minimum of force thereby preventing injury to persons or damage to objects which are inadvertently left in the path of the door when the door is being moved.

Still other advantages and benefits of the present invention will become apparent to those skilled S" in the art upon a reading and understanding of the 0o* following detailed specification.

Brief Description of the Drawings The invention may take physical form in certain parts and arrangements of parts, a preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein: FIGURE 1 is a perspective view of the door operator system according to the present invention in conjunction with a door of a building; FIGURE 2 is side eievational Viev of th' door operator system of FIGURE 1; 7 FIGURE 2A is an enlarged side elevational view, partially in cross-section, of an arm member of the door operator system of FIGURE 2; FIGURE 3 is an enlarged side elevational view, partially in cross-section, of the cylinder of FIGURE 1; and, FIGURE 4 is an end elevational view in cross-section of the cylinder of FIGURE 3.

Detailed Description of the Preferred Embodiment Referring now to the drawings whol:rein the showings are for purposes of illustrating a preferred embodiment of the invention only and not for purposes of S limiting same, FIGURE 1 shows the subject new door operator system A as it is utilized on a door B which closes an opening in a building C. While the door operator is primarily designed for and will hereinafter be described in connection with a sectional overhead sliding door, it should be appreciated that the overall inventive concept involved could be adapted for use in many other overhead and sideward sliding door environments as well.

With reference now to FIGURE 3, the operator 2t system A includes a cylinder member 10 which comprises a tubular body 12 that has an outer periphery 13 having two spaced substantially square sides and two spaced rounded sides (as is more evident from FIGURE 4) and a longitudinal bore 14 extending therethrough. A first end of the bore is closed by a first end cap member 16 with a second, and opposite, end of the bore 14 being closed by a second end cap member 18. Suitable fasteners 20 secure the first and second end caps 16,18 to the tubular body 12. A suitable seal moans 22 is provided for each of the end caps 16,18 to prevent pressurized air from leaking therethrough.

i i- ii iiii~r i -8- As shown in FIGURE 4, a slot 24 extends longitudinally along one of the square sides of the tubular body 12 to communicate the bore 14 with the environment. A pair of spaced sealing bands or strips 25,26 seal the slot to isolate the bore 14 and prevent pressurized fluid from leaking out therethrough. The bands are secured to the two end caps 16,18.

Adapted to reciprocate longitudinally in the bore 14 of tile cylinder is a piston body 30 which is comprised of a pair of identical and opposing sections 32,34 which are joined together in a suitable conventional manner, A seal means 36 extends peripherally around each section 32,34 of the piston to provide a seal between the piston section and the cylinder bore 14.

A piston bracket 38 (FIGURE 4) is secured at a S, yoke-like section 39 by suitable conventional fasteners 40 to the first and second sections 32,34 and is adapted to extend through the cylinder slot 24, A section 41 of the bracket 38 is positioned outwardly of the tubular body 12 and extends along substantially one face thereof as is illustrated best in FIGURE 4. It can be seen in Sthis FIGURE that the bracket 38 is somewhat T-shaped 6' with the section 41 of the T extending outside of the 'ylinder tubular body 12. This outer section 41 has depending sides 42 to each of which is secured an inwardly extending bearing rod 44. The bearing rods slide 4 n suitably configured grooves 46 formed in the outer periphery 13 of the tubular body so as to allow a smooth sliding motion of the piston bracket 38 as the S, piston moves. This system allows the cylinder 10 to withstand high axial and radial loads and moments while eliminating the requirement for external guides and supports.

i 3i 0 -9- Secured to a pair of spaced depending flanges 48 of the piston bracket 38 by suitable conventional fasteners 49 is a carriage 50. The carriage has a base wall 52, a pair of side walls 54, and a pair of opposing end walls 56. Seal means 58 in the form of wiper seals are provided on the end walls 56 of the carriage and act to clean the second seal band 26 of the cylinder With reference now to FIGURE 2, a shock absorbing conn.cting means such as an arm mealis 70 is secured to the carriage 50 in suitable conventional manner. The arm means can be substantially L-shaped as illustrated and includes a first tubular arm member 72 which is secured by a bracket 74 to the carriage Preferably, a fastener 76 which enables a pivoting motion of the arm member 72 with respect to the bracket 74 is provided for securing the arm member to the bracket.

1 A second arm member 78, having a first section S 80 and a second section 82 which is disposed at an approximately 90° angle to the fZIt section is also provided. The second arm member 78 is secured to a bracket 84 by a suitable fastener 86, The bracket 84 is in turn secured to the door B as shown in FIGURE 1.

Preferably, the fastener 86 enables a pivoting motion of 2 5 the second armt member 78 with respect to the bracket 84.

With reference now to FIGURB 2A, a slot extends horizontally in a portion of the second bracket as is iillustrated. A stem portion 92 of the first arm member 72 extends outwardly through the slot 90 of the second arm member. In this way a limit means is provided for the telescoping action of the first arm 72 In the second arm 78. Preferably, a rod mamber 94 extends downwardly from the first arm member 72, In order to provide a resilient biasing moans for the arm 1 a spring 96 is disposed within the first section of the second arm member 78 beneath the first arm 72 such that the rod 94 of the first arm extends thereinto. This positions the spring correctly in relation to the first arm member. Preferably, the spring 96 is a compression spring which resiliently biases the telescoping motion of the first arm member 72 into the second arm member 78.

The arm means 70 also acts as a shock absorber during movement of the door B because of the positioning of the compression spring 96 between the telescoping pair of members 72,78. As is evident from FIGURE 2, the arm means 70 needs to pivot in relation to both the door B and the cylinder 10 during the travel of the door from the closed position to the open position, With reference again to FIGURE 1, a mounting pad 100 is secured to a first end of the cylinder S. with a front mounting bracket 102 securing the mounting S* pad and hence the cylinder to a suitable wall of the building C. A rear mounting bracket 104 is secured to the cylinder and a pair of hangers 106 are fastened to the mounting bracket and to the adjacent ce'ling (not illus tra t d).

Preferably, the door B includes a door tmmber 110 which is made of a plurality of articulated longitudinally extending slats or planks. The door is adapted to slide up and down on a pair of spaced tracks 112, only one of which is illustrated in FIGURE ,1 In general, doors of this nature conventionally include a counterbalancing moans such as an axial torsion spring 114 which is secured above the door B. Cooperating with the torsion spring is a cable 116 which is secured on a first end to the door B (not visible In FIGURE 1) and wound at its second end on a drum 118 axially driven by the torsion spring.

11 J II order to actuate the cylinder 10, a pressurized fluid circuit 120, preferably pneumatic, is provided. The circuit includes a first conduit 122 and a second conduit 124 each of which is in. fluid communication with a respective end of the cylinder through the cylinder ond -Caps 16 A source of pressurized fluid 126 such as a compressor Is in fluid communication with a vespective oiie of the conduits 122,124 as directed by a control means 130. The control lo means can be In the form of a control panel which is Interposed between the condults 122,124 and the source 126 In1 order to control the movement of the rodless pis ton InI the Cylinder.

True con trol means 130 can be ei ther a straight pneuma tic control preyvided with. a conven tional three position directionial valve that Iniclu~des open, Close$ ad s top (rnot shown) or a conventional control module with electrical push buttons for the operations open, close, and stop.

Wi th reference again no IGRi~ bore 140 In the fir'st end cap 16 enables pressurized, fluid from the first conduit 122 to en ter one end of the cylinder behind the pis ton first Section Z to u~rge the pis tonl 0 toward. the second end ca 18ofte cyl Inde The second( conduit 124 extends longi tudinlly down the cylinder 10 atid 1s Secured. thereto by sui table hose clamps 142, The second conduit 121 commnunica tes through bore 1114 in the second end ctip 18 with tho Socoad end of the cylinder. A suitable coniventional adIjostable XX Valve ineans sutii as a needle Valve$ of which a bore 146 Is Illus tra ted, can be provided In. each end cap 10,18 to cushion the movement of the piz:ton 30 adjacent the two ends of the cylindet, 12 As shown in FIGURE 2, if desired, suitable conventional micro switches 150,152 can be secured to the end caps 16,18 to activate additional electronic functions in conjunction with the opening and closing of the door if desired. The micro switches 150,1S2 are connected to the control means 130 by suitable wiring 154. Alternatively, proximity switches can be utilized at the ends of the cylinder. Also, conventional magnetic reed switches could be positioned alongside the cylinder for position sensing of the piston between the ends of the cylinder.

When a pressurized fluid such as compressed air or another suitable compressed gas is supplied by the pres3urized fluid source 126 and the control means 130 is actuated to door open position, the rodless piston 30 and its att lhed carriage 50 will be urged by S S. pressurized air flowing through the first end cap 16 to move from a front end of the cylinder 10 towards a rear end thereof, At this time the air supply port 14 and the second conduit 124 act as an exhaust means for exhausting air from a section of the cylinder between the second section 34 and tlle end cap 18 through tlhe control means 130 to the environment. The carriage Sthus moves pulling the door B with it thereby opening the door. The piston 30 slows down a few inches before contacting the cylinder body second end cap 18, the speed of moveinmit of the piston 30 adjacent the end caps 16,18 can be regulated by moans of the adjustable valve means. Generally, the piston's speed of movement can be 3 regulated through the directional valve in the control means 130.

The piston 30, and hence the carriage SO remains under pressure while the oor B is in the open positiun until the control means 130 receives a signal electrically or manually to shift to another position.

i 13 When the valve 130 shifts to the closing direction, the bore or port 144 in the rear end cap 18 becomes an air supply while the bore or port 140 in the front end cap 16 becomes the exhaust. Therefore, the Sspeed with which the door closes can be different from the speed with which the door opens. In some cases, for example in automated car washes, the door B requires a rapid opening cycle. This can be regulated by the adjustable valve means such as by adjusting the conventional exhaust silencer restrictors on the directional valve in the control means 130. On the other hand, for safety reasons, the closing cycle should be at a normal speed, which is, at a maximum, approximately 1 second per foot as is recommended by the Canadian Door Institute.

a 0 a i owever, the door's speed could be set to slow, S normal, or rapid speed to suit the particular door application involved. This setting can be done through S* an adjustment in the combination of the air flow and the 3 exhaust restrictors. To stop the door at any intermediate position, one merely needs to change the three position control valve to a neutral or stop .4 position in which it will block the flow of pressurized air to either end of the cylinder 10. Also, the motion f the door can instantly be reversed by having the directional valve shift from one direction to the other. This can be done either manually or electrically depending upon the type of controls used.

Since the cylinder 10 operates on a low volume of pressurized gas or air, the cylinder does not move with enough force to cause damage to the door. More Y importantly, the door does not move with enough force to cause damage to objects or be hazardous to personnel.

i 1 14

S

*5 a a.

es a. a

S

When the cylinder 10 reaches the end of its stroke, the door will be in a closed position and will be locked automatically without any additional locking mechanism being necessary since the arm means 70 will be located at a 90° angle to the door B as is indicated in FIGURES 1 and 2. Thus, if the door were attempted to be forced open, the arm means 70 would simply be shoved against the cylinder 10 and the door would not open.

The cylinder 10, carriage 50, and end caps 16,18 can all be made from any suitable material such as anodized aluminum. The piston 30 and the piston bracket 38 can be made from a suitable conventional material such as aluminum or steel. The sealing bands 25,26 can be made from a high density oil, resistant plastic, or another suitable material and the various seals can be made from Buna N or another suitable rubber. One such suitable cylinder assembly is sold by the Norgren Martonair Co. under the designation LINTRA C/45000.

The present invention thus provides a door operator system which minimizes frequent breakdowns, hazard to personnel, and damage to the door or objects which might be in the way of the door. Such a door operator is also believed to have a greatly improved life cycle in relation to the conventional electrically driven chain drive trolley door operators.

The invention has been descri'cd with reference to a preferred embodiment. Obviously, modifications and alterations will occur to others upon the reading and understanding of this specification. It is intended to include all such modiElcations and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

2. The system of claim 1 further comprising bracket means for securing said fluid cylinder to an adjacent wall.
3. The system of claim 1 further comprising a switch means located at each end of said cylinder, each said switch means being in electrical contact with said control means to activate associated electrical comlonents.
4. The system of claim 1 wherein said arm means comprises: a pair of telescoping tubular sections, a first of said sections being secured to said fluid ey cy-i-nd- carriage and a second of said sections being secured to the associated sliding door; and, a resilient means for cushioning the telescoping action of said pair of tubular sections. /4 V 16 0@ S oS S *o S@° o5*° o*oooo @0 S°. S The system of claim 4 further comprising a first pivot means for pivotally securing said first section to said fluid zyl4i:4de carriage and a second pivot means for pivotally securing said second section to the associated sliding door.
6. The system of claim 1 wherein said control means comprises: a source of pressurized fluid; conduit means for connecting said source of pressurized fluid to said fluid cylinder; and, a control panel for controlling the flow of pressurized fluid through said conduit means.
7. The a-ssem4l-y of claim 6 wherein said source of pressurized fluid is in fluid communication with both ends of said fluid cylinder so that it can act on both faces of said rodless piston. S YS t- (Y
8. Tie assemb!l of claim 7 wherein said cylinder is provided with seal means for preventing the pressurized fluid from flowing out of said cylinder.
9. The a-s--e4b4-)t-of claim 8 wherein both ends of said fluid cylinder also include an adjustable valve ieans communicat ing with the environment. An air powered sliding door operator system comprising: a door which Is mounted for sliding movement between a first position in which it closes a building opening and a second position away from the opening*, 17 a rodless air cylinder comprising a cylinder body, a rodless piston adapted for reciprocation in said cylinder body, and a carriage adapted for reciprocation externally along the length of said cylinder body, said carriage being secured to said pis ton; shock absorbing connecting means for connecting said cylindre carriage to said sliding door; and, valve means for selectively feeding pressurized air to said air cylinder to drive said rodless piston and hence said carriage thereby moving said door between said first and second positions thereof.
11. The system of claim 10 wherein the door is an overhead door and further comprising a counterbalance means for counterbalancing the weight of said door. 0
12. The system of claim 11 further comprising guideway means in which said door is movable, and guides secured to said door, said guides engaging said guideway means.
13. The system of claim 12 wherein said air S cylinder longitudinal axis is approximately parallel to a longitudinal axis of said guideway means.
14. The system of claim 10 wherein said shock S absorbing connecting means comprises: a pair of telescoping tubular sections, a 'I first of said sections being pivotally secured to said fluid e-yev1 i4t- carriage and a second of said sections being pivotally secured to said sliding door; and, X i 18 a spring positioned in one of said sections for cushioning the telescoping action of the other of said sections. The system of claim 10 further comprising bracket means for securing said fluid cylinder to a wall surface adjacent said door.
16. An air powered operator system for an articulated overhead sliding door that is movable in guideways which extend upwardly alongside an opening for the door and then rearwardly, comprising: an air cylinder comprising an elongated cylinder body, a rodless piston adapted for longitudinal reciprocation in said cylinder body, and a carriage adapted for reciprocation externally along the length of said cylinder body, said carriage being secured to said pis toi; an L-shaped arm member which connects said e-y ider" carriage to the door; a source of pressurized air which is in fluid communication with said air cylinder; and, 1i valve means interposed between said source of pressurized air and said air cylinder for selectively feeding pressurized air to said air cylinder to S. reciprocate said rodless piston therein.
17. The system of claim 16 wherein said pressurized air is selectively fed to both sides of said i air cylinder to reciprocate said rodless piston therein. i 18. The system of claim 16 wherein said L-shaped arm member comprises: ,f 1 Q- (0 >i 7 1 i i -19 a first tubular section which is straight and is pivotally secured at a first end to said air carriage; a second tubular section which is L-shaped, a first end of said second section receiving a second end of said first section, said second section being pivotally secured at a second end thereof to the door; and, a resilient means for cushioning the telescoping action of said first and second sections.
19. The system of claim 16 further comprising a control means for actuating said valve means and a pair of micro switches one micro switch being located at each end of said air cylinder, said micro switches being in electrical contact with said control means. The system of claim 16 further comprising: a pair of end caps for said cylinder body, each end cap sealing a respective end of said cylinder body, and, an adjustable valve means located in each of said pair of end caps for communicating an interior of said cylinder body with the environment.
21. A sliding door operator system as hereinbefore described with reference to, and as shown in the accompanying drawings, DATED this ELEVENTH day of JANUARY .1990 Anthony G Aquilina Patent Attorneys for the Applicant SPRUSON FERGUSON KLN/1623b KLN/1623b