EP0033199A1

EP0033199A1 - Door structure

Info

Publication number: EP0033199A1
Application number: EP81300119A
Authority: EP
Inventors: Glenn Robert Palmer
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-01-15
Filing date: 1981-01-13
Publication date: 1981-08-05
Also published as: BR8100194A; NZ195942A; NO810095L; FI810010L

Abstract

A door for closing vehicular traffic passages is provided in which the door is a curtain (10) fabricated from a hard flexible material. The curtain runs in opposing channels (14, 15), is mounted on a counterbalanced wind-up drum (17) and under impact changes weight, moves out of the channels and is wound up to open the vehicular passage.

Description

This invention relates to doors and more particularly to overhead doors which are employed in industrial applications.
In situations where doors have to be maintained closed and opened periodically to permit the passage of vehicle traffic the damage to doors has been frequent and extensive and their maintenance and replacement has been expensive. The direct replacement cost alone is enormous and the consequential costs may even be greater. For example in mining applications where sections of a mine are required to be kept at predetermined pressure if a door is damaged such that pressure cannot be maintained then the mine section will be closed.
Present experience indicates that the direct cost of door replacement may involve hundreds of thousands of dollars annually in any one mining application.
Many attempts have been made to reduce these costs. Remote automatic and controls of the door opening and closing operation have been provided through various types of remote sensing. Driver controlled operation has also been provided.
However, while these systems have improved damage control they have not proved to be satisfactory. With remote controls the variable speed of traffic approaching a door is a limiting factor. It is also a factor in driver control. In both cases the response time of the doors is critical and if the driver approaches a door at a higher speed than that permitted by the system response time damage follows.
Too slow an approach leads to a loss of operating efficiency.
The other principal factors in driver control of the door operating functions is the driver's own awareness of the door presence and his response time. Frequently in dark situations the driver is just not aware of his approaching a closed door and damage results.
The other factor is damage to the vehicle. This is also considerably expensive and leads to downtime.

SUMMARY OF THE INVENTION

With these problems and difficulties in mind, the principal objects of the present invention are to provide a door which may be used to close vehicular traffic passages. This invention will be easily and economically repaired and maintained. It will lead to more efficient use of the traffic passage and minimize damage to the vehicle.
To accomplish these objectives there is provided in accordance with the present invention for use as a damage-minimizing door, a flexible curtain having a first end securable to a curtain-rolling mechanism and a second end remote from said first end, said second end including means for varying the weight thereof under impact.
There is also provided in accordance with the present invention a damage-minimizing door which comprises: in combination, a pair of spaced-apart guide means; a flexible curtain having a pair of side edges movably engageable with each of said guide means and.movable out of engagement therewith under a predetermined minimum impact force; and means for moving said curtain between a first door-opening open position and a second door-opening closed position.
No door is completely damage-proof but the present structure has demonstrably reduced damage to both the vehicle and door; is easily installed and maintained; and may be used in aplications of high pressure with facility.

DESCRIPTION OF THE DRAWINGS

These and other features and objects will be more clearly understood from the following description and drawings in which specific embodiments are described by way of example and in which

Figure 1 is a general perspective view of one embodiment of a door structure in accordance with the present invention with the door curtain in a partially lowered position and the door bulk-head shown in dotted outline;
Figure 2 is a general perspective view of the door illustrated in Figure 1 in the door-closed position and under impact from a vehicle shown in dotted outline and serves to illustrate the general concept of the invention;
Figure 3 is a front elevation of the door structure illustrated in Figure 1;
Figure 4 is an enlarged fragmentary front elevation partially in section of the right hand side of the door structure illustrated in Figure 3.
Figure 5 is schematic end elevation partially in section taken along line 5-5 of Figure 3 and serves to show the relationship between a door curtain and its components and the guides therefor with the door curtain in an almost completely open position;
Figure 6 is a further schematic fragmentary end elevation of a door curtain illustrated in Figure 4 in a lowered position;
Figure 7 is an enlarged fragmentary perspective view of the lower end of the embodiment of a door curtain-illustrated in the previous drawings and serves to illustrate the structural relationship between a base bar and a curtain;
Figure 8 is a schematic enlarged end elevation of the bottom of one curtain structure of the type shown in Figure 6 and serves to illustrate the disconnection under impact between a base bar and a curtain door;
Figure 9 is an enlarged fragmentary perspective view of a curtain, base bar and serves to illustrate their respective disconnection under impact.
Figure 10 is an enlarged exploded view of a guide roller mounting in accordance with the present invention
Figure 11 is an enlarged front elevation, partially in section, of a guide roller mounting in-accordance with the present invention;
Figure 12 is an enlarged perspective view of the bottom of an alternate embodiment of a door curtain in accordance with the present invention;
Figure 13 is an enlarged schematic view of the door curtain illustrated in Figure 12 showing the action between curtain components under impact;
Figure 14 is an enlarged schematic view of the bottom of a curtain of a further alternate embodiment of a curtain in accordance with the present invention;
Figure 15 is an enlarged fragmentary view of an alternate door curtain construction and illustrates its relationship with the curtain guides.
Figure 16 is an enlarged schematic plan view of the structure illustrated in
Figure 15 and serves to illustrate through dotted outline the relationship of the various components under impact;
Figure 17 is a schematic fragmentary end elevation of. an alternate door structure in a lowered position;
Figure 18 is a plan section of one side of the lower end of an alternate curtain structure in accordance with the present invention; and
Figures 19 and 20 are further plan sections of one side of the lower end of alternate curtain structures in accordance with the present invention.

THE STRUCTURE

Referring now to the drawings and more particularly to Figure 1 it will be noticed that the door structure itself is indicated at 10 and comprises a curtain of flexible material.
In the embodiments illustrated the curtains are manufactured of rubber. In the sense in which the term "rubber" is employed in this specification it should be understood that it includes any suitable flexible materials which have resilient capabilities or the capacity to retain their form.
It will also be understood that where fibre is a potential hazard that suitable non-toxic rubbers or equivalent materials would be employed. Such rubbers are identified as Type 1 - Wingprene (neoprene) and Type 11 - SBR.
With structures of the present invention, depending on the particular application it may be necessary to provide bulkheads. Such bulkhead is illustrated in Figure 1 and comprises vertical steel members 11 and 12 and a cross piece 13.
To each vertical member an inwardly facing guide channel such as 14 and 15 is secured in aligned opposite relationships. At the top and on the outerside of the vertical 14 away from the traffic flow a motor 23 and clutch 23 assembly 16 is mounted. The motor may be operated in any conventional manner by remote or manual controls; the choice depends upon the application.
Curtain 10 is secured along its top edge to a drum 17 as illustrated in Figure 5. This securement may be as illustrated by a series of openings such as 100 provided adjacent the upper end of the curtain 10 with parallel bars 101 and 102 on either side of curtain 10. Securement is accomplished by bolts and nuts such as 103 and 104. Drum 17 is rotatably supported in mounting brackets 30 & 31, is stepped as at 18 to ensure uniform winding and unwinding of the curtain sheet 10 and is connected through a shaft 19 chain drive 20, clutch 21, and a worm and screw 22 to a motor 23.
Drum 17 is provided at each end with torsion springs such as 24 as illustrated in Figure 4. These torsion springs serve to wind up the curtain 10.
As shown in particularly Figures 4, 5, 10 and 11 a guide roller 26 is also rotatably mounted in brackets 30 and 31. Roller 216 is mounted forward and below of the axis of rotation of drum 10 that is at position such that is substantially tangential to the channels 14 and 15 and defines one side of a throat to guide curtain 10.
The remaining side of the throat is defined by a bracket or bar 27 which presents a downward curved surface toward the adjacent channel mouth.
In Figure 17 an alternate structure is illustrated. As shown in this drawing the channel 15 is provided with curved upper ends which curve towards the idler roller 26. The inner wall 160 of guide channel 15 is also lockably hinged at 161 so that it may be folded down when the curtain 10 has to be reinserted in the channel.
Roller 26 is supported at the motor side at least by a plate 33 which may be adjustably secured horizontally and vertically to the housing plate 31. Plate 33 in turn supports a universal bearing 34 which supports a roller shaft 35.
This arrangement facilitates adjustment in mounting the guide roller 26 in installation and maintenance. The correct guidance of the rollers and consequently the curtain is important if the curtain is of rubber since there is a tendency for rubber to bind against metal and this will prevent free-running of the curtain.
It is also to be noted that the guide roll 26 is mounted on that side of the curtain which is presented in those applications where there is a pressure differential across the curtain, to the lower pressuure side. Under such conditions the curtain 10 has a tendency to bow to the negative pressure side and it is necessary to maintain contact with the curtain to ensure that it runs properly and keeps in the channels.
The curtain itself is preferably of a hard flexible rubber composition. On the outside vertical edges a further strip of rubber, 40, as shown in Figures 9, 15 and 16 may be provided. Or the curtain may be of thicker construction at the edge. This assists in sealing, particularly in applications where higher pressure may be required. In this context high-pressure is meant to include all pressures within the range 15 lbs./sq.ft. (atmospheric) to 45 lbs./sq.ft. (2.5 Waters GA). Strip 40 while assisting sealing does not increase the weight of the curtain 10 appreciably. However, as seen in Figure 15 where lateral guide rollers such as 41 are mounted on the channels it serves as a convenient engagement area.
It will also be noted that in the embodiment of Figure 15 a further roller 70 is mounted on each end of base bar 50 to engage the forward and rear walls of the channels 14 and 15 and provide further guidance to the curtain 10.
These rollers being within the channels 14 and 15 will not be exposed to too much damage.
Base bar 50 comprises a pair of spaced apart angles 52 and 53 which are connected by a flat bar 54. Bar 53 is provided with a series of threaded bolts which pass through and engage a securing strip 55. It is to be noticed, from Figure 7, that where the securing strip basses between the walls of the channels 14 and 15 the strip is rounded to ease any friction. This base bar serves to stiffen the lower end of the curtain.
The lower edge of curtain 10 is passed between angle 52 and strip 55 and the bolts are tightened so that the engagement between the bar and the curtain is tight but releasable. The amount of force required to release the bar may be adjusted according to the pressure.
In the structures illustrated in Figures 12, 13 and 14 two alternative structures are provided.
In. the structure of Figures 12 and 13 a rubber tube 55 with an interior coiled spring 56 is substituted for the base bar and this structure is connected by a grooved channel 57 to the lower edge of curtain 10.
In the structure of Figure 14 a hollow rubber tube 60, closed at both ends is secured, either permanently or removably to the lower edge of curtain 10. This tube has a series of holes 61 on the upper surface.
The internal chamber of the tube 10 may then be filled with a suitable fluid which may be added to or escape through the holes 61.
In the embodiments illustrated in Figures 18 through 20 various alternate curtain structures are illustrated. Corresponding components are correspondingly numbered in these figures to those of other figures. In each of these structures the curtain 10 is provided with a thickened area 110 which may have the alternate configurations illustrated in the respective figures. And in each structure the guide channel has a throat of reduced width for restraining movement of the curtain out of the channel. In Figure 18, the channel is constricted by angle 130; in figure 19 by opposed angles 131 and 132 and in Fig. 20 by the configuration of the open tube structure of the channel itself.
In each of these structures the throat is narrower than the curtain edge. This precludes lateral movement of the curtain 10. It will of course be understood that the remote lateral side of the curtain and its corresponding guide channel are of the same structures.
It will of course be understood that other flexible or compressible materials than rubber may be employed.
In those applications where the passages of gases is not important permeable materials may be employed.

MODE OF OPERATION

The mode of operation of the present invention is extremely simple. It is assumed that the door 10 is down.
Essentially, if a driver fails to open the door 10 or if it fails to open before it is hit by a vehicle at impact, as illustrated in. Figures 2, 8, 9, 13 and 16, the _; base bar 50 or tube 55 are released and fall to the ground and the vertical edges of the curtain 10 will retreat before the vehicle and be pulled out of their guide channels 14 and 15 in the manner illustrated in the drawings. This action holds true irrespective of the height of the door above the ground as long as it is within vehicle contact. Thus even if the door is half-way up or down the same action will hold. With the release of the bar the tension on springs 24 is released and the shaft 19 is rotated so as to wind up curtain 10. Clutch 21 is simultaneously disconnected of slips so that shaft 19 is free to rotate. The accurate winding of the curtain is ensured by guide roller 26, guide bars 27 and the further fact that drum 17 is stepped to ensure circular winding motion.
Since the curtain is of rubber it will give with the force and unless it is hit with considerable speed, more than is normally permissible at least in mining applications it will be substantially undamaged.
Indeed the vehicle operator can dismount operate the curtain motor to lower the curtain which will follow in its guide channels, attach the bar 50 or tube 55 and proceed.
With the embodiment illustrated in Fig. 17 the insertion of the curtain 10 into the guide channels is facilitated by the hinge. By folding down the upper ends of the channels as illustrated in dotted outline the curtain 10 may easily be fed into the channel.
With the embodiment illustrated in Figure 14 the tube 60 may not be detachable and upon impact some of the fluid in the chamber will be discharged through the openings 61 so that again the torsion balance is upset and the curtain is wound up.
It has been found as mentioned previously in ; experiments that these doors are capable of withstanding great pressures and that they can be subjected to all manner of abuse which other forms of solid doors have not been able to withstand.
It will be apparent that an extremely simple solution has been provided where many other forms have been tried without much success.
It will also be obvious that other forms may be given and modifications may be made to the embodiments disclosed in this present application without departing from the essence of the invention.

Claims

1. For use as a damage-minimizing door, a flexible curtain having a first end securable to a curtain-rolling mechanism and a second end remote from said first end, said second end including means for varying the weight thereof under impact.

2. A flexible curtain as claimed in Claim 1 wherein said means for varying the weight thereof comprises a weight secured to said curtain adjacent said second end and releasable therefrom under vehicle impact.

3. A flexible curtain as claimed in Claim 1 wherein said means for varying the weight thereof includes compressible means defining a liquid containing chamber having at least one opening to the exterior to permit liquid passage therethrough under vehicles impact and vary the weight thereof.

4. A flexible curtain as claimed in Claim 1, 2 or 3 further including vertical edges extending between said first and second ends, and sealing means extending along said vertical edges.

5. A flexible curtain as claimed in any of the preceding claims wherein said curtain is of rubber.

6. A flexible curtain as claimed in Claim 2 wherein said weight is pressurably secured to said curtain.

7. A damage-minimizing door which comprises: in combination, a pair of spaced-apart guide means; a flexible curtain having a pair of side edges movably engageable with each of said guide,means and movable out of engagement therewith under a predetermined minimum impact force; and means for moving said curtain between a first door-opening open position and a second door-opening closed position.

8. A door as claimed in Claim 7 wherein said guide means comprises a pair of channel members.

9. A door as claimed in Claim 8 wherein said guide means further includes roller means mounted adjacent upper ends of said guide means and aligned therewith to facilitate movement of said curtain therein.

10. A damage-minimizing door as claimed in Claim 9 wherein said door further includes curtain-weight-varying means responsive to a minimum impact force upon the curtain to reduce the weight thereof.

11. A damage-minimizing door as claimed in Claim 10 including curtain-winding means responsive to a reduction in curtain weight under impact to raise the curtain to said first door-open position.

12. A damage-minimizing door as claimed in Claim 11 wherein said curtain-winding means includes a pair of torsion springs.

13. A damage-minimizing door as claimed in Claim 7 wherein said flexible curtain is compressible and includes a thicker area along each edge thereof engageable with said guide means; said,guide means including means for restraining movement of said curtain laterally out of said channel.

14. A damage-minimizing door as claimed in Claim 13 wherein said restraining means comprises roller means engageable with an inner side surface of said thickened areas.

15. A damage-minimizing door as claimed in Claim 13 wherein said restraining means includes projections extending into a channel defined by said guide means to provide a throat of reduced dimensions relative to said thickened area of said curtain to restrain lateral movement of said curtain.

16. A flexible curtain of compressible impervious material for use as a door which comprises a continuous sheet having a first end, a second end and a pair of lateral edges extending between said first and second ends, said first end being adapted for releasable securement to a supporting structure; and said sheet being a thicker area adjacent each of said lateral edges to engage and be releasably retained by guide channels disposed on each side of said curtain.

17. A flexible curtain as claimed in Claim 16' including a stiffening member secured adjacent said second end.

18. A flexible curtain as claimed in Claim 16 wherein said thicker areas have a reducing thickness inward toward a main axis of said sheet.

19. A door as claimed in Claim 8 wherein said curtain has first central area of predetermined thickness and a thicker area extending substantially along each side edge thereof; and said channel members each have inner edges, restraining means mounted adjacent said inner edges of said channel members engageable with said curtain adjacent said side edge to restrain lateral movement thereof.

20. -A door as claimed in Claim 8 wherein said channel members each include an upper portion movable from a closed channel position to an open channel position to provide access to said channel.