US 3714737 A
The invention relates to operating mechanism for a vertically sliding door of a washing machine for laboratory equipment in which the door is raised to the open position by hydraulic pressure and is lowered to the closed position by gradually releasing the hydraulic pressure in such a way that during the downward run of the door the same is only under the influence of its own weight, so as to avoid accidental injury to the operator or damage to the equipment being washed.
Description (OCR text may contain errors)
United States Patent 119 Fillion et a].
[ 1 OPERATING MECHANISM FOR VERTICALLY SLIDING DOOR  Inventors: Paul-Henri Fillion, Ste-Foy, Quebec; Viateur Guay, Charlesbourg, Quebec, both of Canada  Assignee: Hoplab Inc., Quebec, Canada  Filed: Feb. 8, 1971  Appl. No.: ll3,488
52 u.s.c1 ..49/360,49/139 511 1m.c1. ..E05f 15/08  Field ofSearch ..49/139,140,360 362;- 91/391; 92/172, 187; 98/115 LH; 312/209  References Cited UNITED STATES PATENTS 546,854 9/1895 Holbrook etal. 49/361, 2,844,967 7/1958 Leber ..92/l 87 X 111 3,714,737 1451 Feb. 6, 1973 Primary Examiner-.l. Karl Bell Att0meyRaymond A. Robic 5 7 ABSTRACT The invention relates to operating mechanism for a vertically sliding door of a washing machine for laboratory equipment in which the door is raised to.
the open position by hydraulic pressure and is lowered to the closed position by gradually releasing the hydraulic pressure in such a way that during the downward run of the door the same is only under the influence of its own weight, so as to avoid accidental injury-to'the operator or damage to the equipment being washed.
7 Claims, 6 Drawing Figures PATENTEU FEB 6 I973 SHEET 10F 2 A IN VENTO RS Paul-Henri FILLION Viuteur GU Y PATENTEDFEB 6 I975 3.714.737 SHEET 2 0F 2 INVE NTORS 4 Poul-Henri FILLION Vioteur GUAY OPERATING MECHANISM FOR VERTICALLY SLIDING DOOR The present invention relates to operating mechanism for a vertically sliding door.
The invention is particularly concerned with doors of washing machines for laboratory or medical equipment. Such machines are usually mounted in the wall between a controlled environment room such as a laboratory or an operating room and the outside, and are provided with doors which open on opposite sides of the wall, so that soiled or unsterile equipment can be placed in the machine from the outside area with the inner door closed, subjected to a washing operation and then removed when needed from inside the controlled environment room with the outside door closed or vise versa. This procedure minimizes the danger of contamination being admitted into the operating room or laboratory during time when it is essential to maintain aseptic conditions, which time coincides of course with periods when prompt and continuous supply of equipment must be maintained.
Vertically sliding doors are preferably used in such machines because they require a minimum of space in relation to the size of the opening they provide, they do not interfere with the loading and unloading of the machine and they insure a good seal around the door during the washing operation.
Hitherto employed mechanical systems for the operation of such vertically sliding doors have proved relatively unsatisfactory, however, because failure of essential parts of the mechanical system can lead to sudden dropping of the door and injury to the operator and damage to the equipment being treated. Because of the critical time factor involved in surgical operations, such accidents may have tragic results far beyond their immediate effect because of the time loss involved in repairing the washing machine and replacing the damaged equipment.
The problem is made more acute by the fact that in order to withstand the stresses imposed by the washing operation and to hold up under constant use, the doors have to be sturdy and thus relatively heavy.
It is also difficult to keep the mechanical systems properly lubricated due to their exposure to the washing fluid, all of which leads to faulty operation.
The .conventional mechanical door opening devices have the further disadvantage of complexity of design, which makes it likely for pockets of fluid to be trapped within the mechanisms thus leadingto corrosion of the parts exposed as well as to dangerous septic conditions.
The present invention seeks to obviate the aforementioned disadvantages of conventional mechanical systems by providing in their stead an operating mechanism for vertically sliding doors of washing machines, whose functioning is entirely hydraulic.
The use of hydraulic means, furthermore, increases the safety of the system. In fact, should the operator accidentally place part of his or her body in the path of the descending door, such body part will then only have to support the weight of the door and no injury will result because of the gentleness of the initial contact due to the gradual descent of the door.
In accordance with the invention, the operating mechanism comprises hydraulic cylinders vertically mounted under the door, with a piston mounted in each cylinder and a rod disposed between each piston and the door, the rods being arranged with their ends removably resting on the pistons.
The absence of a positive attachment between the rod and the piston in accordance with the invention has the advantage of inherent simplicity of construction.
A further advantage is that the door can be raised manually without carrying the piston along with it. This facilitates cleaning of the rod end and also makes it easier to open the door in case of failure of the hydraulic system from causes such as a drop in pressure or a stoppage in the pipes.
A preferred embodiment of the invention is illustrated by way of example in the accompanying drawings in which:
FIG. 1 is a perspective view of a washing machine for medical of laboratory equipment having vertically sliding doors outfitted with an operating mechanism according to the invention;
FIG. 2 is a vertical longitudinal fragmentary section of a hydraulic cylinder, piston and rod assembly and adjacent portion of the door;
FIG. 3 is a fragmentary horizontal cross-section of the door;
FIG. 4 is a diagrammatic plan of the washing machine cabinet mounted in a wall;
FIG. 5 is a schematic view of the hydraulic system in the rising or opening condition; and
FIG. 6 is a schematic view of the hydraulic system in the descending or closing condition.
As shown in FIG. 1, the washing machine comprises a metal cabinet 10 with side walls 11 and opposite front and rear walls 12 provided with removable top and bottom panels 13 and 14 with an opening therebetween in which fits a door 15.
Each door 15, as also shown in FIG. 3, consists of a tempered glass panel 16 mounted in a metal frame 17 through the intermediary of a gasket 18. The door 15 is provided with channels along its vertical sides which run in vertical slides 19 secured to the front and rear walls 12 on either side of the opening and behind the top panel 13. The doors 15 are thus slidable between a topmost open position (shown in dotted lines) and a bottom position in which they close the respective openings of the front and rear walls 12.
FIG. 4 shows the washing machine cabinet mounted in the wall A of a controlled environment room B such as an operating room or a laboratory, in such a way that soiled or unsterile equipment can be introduced from an outside area C by opening the door 15 on that side while leaving the opposite door 15 closed, treated in the washing machine with both doors l5 closed, and then removed in the controlled environmentroom B by opening the door on that side while leaving the opposite door closed so that direct contact with the outside can be completely avoided.
A control panel 20, mounted on the front wall 12, carries a plurality of control knobs, buttons and dials 21, some of which serve to direct the washing operation, while others are for raising and lowering the doors 15. A similar control panel (not shown) is provided on the rear wall 12.
The hydraulic system for raising and lowering the doors 15, with which the'present invention is particularly concerned, comprises for each door 15 a pair of hydraulic cylinders 22 mounted vertically under the door 15 on either side thereof behind the removable bottom panel 14, as illustrated in FIG. 1. Each cylinder 22 is open at the top as shown in FIG. 2 and contains a rubber or plastic piston 23 having at the bottom a flexible sealing flange 24 which is forced by hydraulic pressure against the cylinder wall.
Each piston 23 has on the upper face thereof a shallow hemispherical socket 25 in which rests the correspondingly rounded end of a rod 26. The upper end 27 of rod 26 is threaded and screwed into a correspondingly threaded bore 28 opening onto the bottom face of the door 15. A nut 29 is mounted on the threaded end 27 of rod 26 and locks against the bottom face of door 15 once the projecting length of the rod has been adjusted to a slightly greater dimension than the full sliding run of the door 15.
The two cylinders 22 for each of the doors 15 are interconnected by a cross pipe 30. At the bottom of the cabinet 10, a supply pipe 31 (FIGS. and 6) feeds through a flow control valve 32 with an adjustable orifice and a solenoid actuated valve 34 into a connection pipe 35 opening into cross pipe 30. Downstream of the connection pipe 35 is a drain pipe 36 also containing a solenoid actuated valve 37 and a flow control valve 38 similarly provided with an adjustable orifice.
A branch with a supply pipe 39 having a solenoid actuated valve 40 and a drain pipe 41 having a solenoid actuated valve 42 is connected in parallel with valves 34 and 37 and in series with flow control valves 32 and 38 and joins with a connecting pipe 43 feeding the cross pipe 30 for the two cylinders 22 which operate the other door 15.
To raise and open either door 15, the corresponding valve 34 or 40 is opened while the corresponding valve 37 or 42 stays closed, whereby pressure fluid is admitted in equal proportion into the two corresponding cylinders 22. Valve 34 or 40 can be closed to'hold the door in any desired position.
To lower and close either door 15, the corresponding valve 37 or 42 is opened while the corresponding valve 34 or 40 stays closed, whereby'the fluid in the corresponding cylinders 22 is forced and drained out of them by the weight of the door acting through rods 26 and pistons 23.
While the two doors can be operated independently because of the parallel arrangement of valves 34, 37, 40 and 42, the speed at which they open and close is adjusted collectively by setting flow control valves 32 and 38 respectively.
The operating members such as push-buttons or switches for valves 34, 40 and for valves 37, 42 are preferably located on the control panels on the sides of the cabinet of the corresponding'doors 15 which they control, so that each door 15 can only be opened from the corresponding side of wall A.
For cleaning purposes, the doors 15 can be raised manually thereby exposing the ends of rods 26, and enabling removal of pistons 23.
The fluid fed to supply pipe 31 is preferably water at city system pressure which can thus be carried by drain pipe 36 to city system drains without the need of recirculation. This arrangement also obviates the necessity for any special power supply to operate the doors 15. The required connections to city water supply and drain present no complication since such connections are required in any case for the operation of the washer.
In its open position, each door 15 trips a cut-off switch 44 which renders the washing system inoperative. Similarly, the washing system may include a cutoff switch (not shown) which prevents operation of the door opening valves 34 and 40 while the washing machine is in operation. A cut-off switch (not shown) may also be provided to limit the topmost position of the door.
1. Operating mechanism for a vertically sliding door comprising:
at least one hydraulic cylinder vertically mounted under said door,
a piston slidably mounted in said cylinder,
a rod disposed between said piston and said door,
a supply pipe and a drain pipe connected to said cylinder,
a first valve located in said supply pipe for permitting fluid to enter the supply pipe when the first valve is opened so as to move said piston upwardly and raise the sliding door, second valve located in said drain pipe for permitting said fluid to escape through the drain pipe under the pressure exerted by the sole weight of the door acting on said piston when it is desired to lower the sliding door, and a control valve having an adjustable orifice located in both said supply and drain pipes so as to control the rate of opening and closure of the sliding door. 2. Operating mechanism for a vertically sliding door according to claim 1, wherein each piston has a shallow socket on the upper face thereof, and said rod end rests in said socket whereby the door can be raised manually without carrying the piston with it for cleaning the rod or in the case of failure I of the operating mechanism.
3. Operating mechanism for a vertically sliding door according to claim 2, wherein said socket is hemispherical, and
said rod end is correspondingly rounded. 4. Operating mechanism for a vertically sliding door according to claim 1, wherein said rod is threaded at its upper end, I said door has a corresponding bore opening on the bottom face thereof, said bore receiving said threaded rod endso permit longitudinal adjustment of said rod. 5. Operating mechanism for a vertically sliding door according to claim 4, wherein said threaded rod end has a nut mounted thereon locking against the bottom face of said door. 6. Operating mechanism for a vertically sliding door according to claim 1, wherein there are two such cylinders mounted at either side of said door, said two cylinders being hydraulically interconnected. 7. Operating mechanism for a vertically sliding door according to claim 1, wherein said first and second valves are solenoid actuated valves.