Description:
The present invention relates generally to an improved overhead grille, and more particularly an overhead grille capable of emergency ascending movement from its closed position so as to provide an emergency or exit opening beneath its lower edge.
In accordance with typical lock-up or closing procedures, a storekeeper will usually lower his overhead grille into its fully closed position in front of his store front at store closing time in order to prevent additional customers from entering the store. At the time of said closing, however, there may still be some customers within the store who have to be let out by the proprietor, sometimes even one at a time. The foregoing represents a dangerous situation since, when the grille is in its fully closed position across the store front and individuals are still within the store, in the event of a fire occuring at that time, the closed grille will prevent the escape of these individuals from the store. There is no provision for avoiding this dangerous situation with any known overhead grille except by causing ascending movement of the same by initiating operation of the powering motor. This might not be possible, however, because of a power failure caused by the fire.
Broadly, it is an object of the present invention to provide an overhead grille with an emergency opening capability to thereby overcome the foregoing and other shortcomings of the prior art. Specifically, it is an object to incorporate as part of the grille a means for automatically causing lifting movement therein merely upon the actuation of an emergency switch or other such control, thereby providing an emergency escape opening beneath the grille without the need to commence operation of the grille motor operator.
An overhead grille demonstrating objects and advantages of the present invention employs the motor that powers the grille through opening and closing movements to also load a spring capable of opening the grille, and includes an emergency disconnect of the motor drive connection to the grille which disconnect, when operated, releases the energy or urgency of the loaded spring so as to cause emergency opening movement in the grille.
The above brief description, as well as further objects, features and advantages of the present invention, will be more fully appreciated by reference to the following detailed description of a presently preferred, but nonetheless illustrative embodiment in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a front elevational view of an overhead grille in a partially open position providing an escape opening thereunder;
FIG. 2 is a partial front elevational view, in section, illustrating details of the overhead support for the grille and the manner of raising the grille to provide said emergency escape opening;
FIGS. 3a and 3b are simplified elevational views respectively showing the grille in its closed position and in its slightly raised position providing said emergency escape opening;
FIG. 4 is a partial perspective view illustrating details of the motor drive connection for the grille and of the manner of disconnecting the same incident to providing said emergency escape opening; and
FIG. 5 is a perspective view illustrating structural details of a toggle switch which is advantageously utilized in an emergency grille-opening means according to the present invention.
Reference is now made to the drawings and in particular to FIG. 1 wherein there is shown an overhead grille, generally designated 10, demonstrating objects and advantages of the present invention. As generally understood, an overhead grille consists of a series of horizontally oriented tubes, or the like, individually and connectively designated 12, which are joined together by strategically spaced links 14. As further generally understood, grille 10 is helically wrapped about a horizontally oriented support within an overhead structure 16 above a store front 18 and is typically powered by a motor 20 through opening and closing movements relative to the store front 18.
In accordance with normal or typical lock-up or closing procedures, a storekeeper will lower the grille 10 into its fully closed position in front of the store front 18 at store closing time in order to prevent additional customers from entering the store. At the time of said closing, however, there may still be some customers within the store who have to be let out by the proprietor, sometimes even one at a time. It has been recognized that a dangerous situation exists when the grille 10 is in its fully closed position across the store front 18 and individuals are still within the store, since in the event of a fire occuring at that time the closed grille 10 will prevent the escape of these individuals from the store. Thus, in accordance with the present invention, an emergency grille-opening means, generally designated 22, is included as an operative part of the overhead grille 10, said means 22, when operated, resulting in the grille 10 automatically partaking of ascending movement to the extent illustrated in FIG. 1 which provides an emergency escape or exit opening 24 between the grille lower edge and ground level. That is, grille 10 moves from its completely closed position, as illustrated in FIG. 3a, into a slightly raised position, as illustrated in FIG. 3b, in which there is sufficient clearance 24 beneath the lower edge of the grille 10 for an adult to duck under the grille during an emergency escape, should it be necessary to do so.
An exemplary way of incorporating in the mode of operation of the grille 10 provision for providing the emergency opening 24 thereof is illustrated in FIGS. 2, 4 and 5 to which reference is now made. Within the overhead structure 16 is a cylindrical member 26 which serves as a support for the grille 10 which is helically wrapped about the support 26. At one end extending within the interior of the support 26 is a shaft 28 rotatably disposed through bearings 30 and 32 and an end closure member 34, so that the shaft 28 can and does rotate relative to the support 26. A helical spring 36 is disposed along the shaft 28 and has one end 30 affixed to the shaft 28 and its opposite end 40 appropriately fixed to the interior of the support 26. As a consequence, shaft 28 can be rotated in a clockwise direction, as viewed from the left in FIG. 2, for example, and thus cause a corresponding increase in the bias or urgency in the spring 36 which tends to produce rotation in the support 26 in a counterclockwise direction. This direction of rotation of support 26 will be understood to result in wind-up of the grille 10 upon the support 26 and thus ascending movement of the lower portion of the grille 10, all as is illustrated in FIG. 3b. In accordance with the present invention, shaft 28 is rotated through an appropriate number of revolutions to load spring 36 so that the corresponding urgency of the spring 36 is sufficient to overcome the weight of the grille 10 and result in an appropriate number of revolutions of the support 26 which produces the previously noted opening 24 beneath the grille 10. The amount of spring urgency within the spring 36 to achieve this is a function of the weight of the grille 10. Once the shaft 28 is rotated to provide the urgency within the spring 36 as just indicated, the pawl and rachet arrangement 42 on the shaft 28 is utilized to hold the shaft 28 against rotation, and thus the spring 36 in its tensioned condition.
At the other end of the support 26, said support has a driving connection to the powering motor 44 and thus until this driving connection is disconnected, spring 36 cannot raise grille 10 to provide said exit opening 24. Specifically, and as is perhaps most clearly illustrated in FIGS. 4 and 5 in connection with FIG. 2, the driving connection of the motor 44 includes a motor shaft 46 having a driving pin 48 extending therefrom. Cooperating with the driving pin 48 and slidably disposed on the motor shaft 46 is a driving member 58 which has a notch 52 in which the driving pin 48 is normally accommodated. A helical spring 54, seated at one end against a stop 56 and at its other end against the driving member 50 is effective in holding notch 52 about the driving pin 48 and thus in providing a driving relationship between the motor shaft 46 and the driving member 50.
Powering rotation of the driving member 50 is transmitted via an endless loop of chain 58 to a driven member 60 which is fixedly mounted on a shaft 62 which extends within the cylindrical grille support member 26. As is perhaps best shown in FIG. 2, shaft 62 is mounted in bearings 64 and 66 and is fixedly connected to disks 68 and 70 which are each fixedly connected in an appropriate manner, as by welding, to the interior wall of the support 26. Thus, the rotation of driving member 50, which is transmitted to driven member 60, is transmitted to the shaft 62 and produces corresponding rotation in the support 26. In this manner, motor 44 is effective in powering shaft 62 in one direction of rotation which results in descending movement of grille 10 into its closed position, or in an opposite direction of rotation which results in ascending movement of grille 10 into selected open positions.
As long as motor shaft drive pin 48 occupies its driving relation with respect to the notch 52 and thus the driving connection between the motor 44 and the support 26 is intact, there can be no ascending movement in the grille 10 caused by the urgency of the helical spring 36. However, when the aforesaid driving relation or connection between the motor 44 and support 26 is disconnected, it should be readily appreciated that helical spring 36 is then effective in causing counterclockwise rotation in the support 26 and thus in lifting grille 10 into its FIG. 1 position, which provides the exit opening 24.
To initiate said ascending movement of grille 10 there is provided a cable 72 which is threaded over a pulley 74 and has a swivel connection 76 to a bar 78 which has rod connections 80 and 82 to the driving member 50. By pulling down on the free end 84 of cable 72, driving member 50 is urged through sliding movement 87 along the motor shaft 46 which results in disengagement of notch 52 from about the driving pin 48. It should be noted that the slight sliding movement 87 required in the driving member 50 is permitted within the normal slack of the chain 58 which is entrained about the driving and driven sprockets 50 and 60, respectively.
Assuming that driving member 50 is moved into its clearance position from drive pin 48 when the grille 10 is in its fully closed position as illustrated in FIG. 3a, the result is that shaft 62 is no longer held against rotation by the motor 44 but instead is free-wheeling. In the free-wheeling condition of shaft 62, support 26 is then subject to the urgency of the helical spring 36. Specifically, spring 36, as previously indicated, is wound in that direction of rotation which induces the same to cause wind-up rotation in the support 26. As a consequence of this wind-up rotation in the support 26, the grille 10 is raised through ascending movement which provides the exit opening 24.
As illustrated in FIG. 4, driving member 50 is normally under the urgency of spring 54 to assume a position on motor shaft 46 which establishes the driving connection between the notch 52 and pin 48. Thus, after pulling manipulation of the cable 72 which disengages member 50 from the pin 48, member 50 must be held in its position of movement during the interval of operation of the helical spring 36. One exemplary manner of holding member 50 in its disengaged position is illustrated in FIG. 5 and consists of a toggle switch, generally designated 86. As illustrated in FIG. 5, toggle 86 includes bar 90 and link 88 pivotally connected to the cable 72 while the free end of bar 90 supports one end of a positioning spring 94. As generally understood, when the link 88 is moved from its solid-line position, as illustrated in FIG. 5, in response to pulling down on the cable 72, into its position illustrated in phantom perspective in FIG. 5, this rotatable traverse changes the biasing effect of the spring 94. Specifically, in the phantom perspective position, spring 94 holds link 88 in its rotated position, and thus also holds cable 72 in its corresponding actuated position. Thus spring 94 effectively opposes spring 54 and driving member 50 is held disengaged from the driving pin 48.
From the foregoing, it should be readily appreciated that there has been described herein an emergency grille-opening means which, when operated, will cause automatic opening movement in the grille 10 from its fully closed position to a slightly raised position which thus provides an exit opening 24 beneath the lower edge of the grille 10. In a preferred embodiment, and as illustrated in FIG. 2, a sign 96 is advantageously posted in a visible position adjacent the cable end 84 to indicate the herein described noteworthy emergency mode of operation of the improved overhead grille 10 hereof.
A latitude of modification, change and substitution is intended in the foregoing disclosure, and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.