Abstract:
A device for temporarily disabling a doorknob attached to a hinged door. The device covers the doorknob with a rigid enclosure, preventing rotation of the doorknob to move the associated locking bolt. A retaining unit is mated with an extension from the rigid enclosure in a male-female relationship, simultaneously with fitting the retaining unit over the outer edge of the hinged door while ajar. Closure of the door into the associated doorjamb, with the enclosure over the doorknob, prevents parting movement between the enclosure and the retaining unit, providing a self-locking feature.

Description:
This application claims the benefit of provisional application 60/263,349 filed Jan. 22, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     The concept of placing a cover enclosure over a rotational doorknob, to prevent rotation of the doorknob, and concurrent dislodging of the associated locking bolt, and, finally, opening of an associated door, is, generally known. U.S. Pat. No. 4,285,221, to Atchisson, discloses a retrofit doorknob lock apparatus, in which a shroud is placed over the doorknob and the doorknob shaft and a clevis fits through slots in the shroud to retain the shroud in place. The clevis is locked in place with a separate exterior lock, on the same side of the door. Similarly, U.S. Pat. No. 3,739,608, to Young, discloses an auxiliary door lock including a doorknob cover, a resilient band along the inner wall surface of the cover, and a locking means, again on the same side of the door, utilizing a separate, exterior lock. The door lock of U.S. Pat. No. 4,876,867, to Leneave, again discloses a cover, comprised of a tubular casing, which fits over a doorknob, on one side of the door, with a locking lever, utilizing a separate lock, again, on the same side of the door. U.S. Pat. No. 5,425,256, to Crosby, for a doorknob security device, also utilizes a cover mechanism, kept in place by a separate lock, on the same side of the door. The lockable doorknob enclosure of U.S. Pat. No. 5,560,235, to Aucoin, again deals with an enclosure which fits over a doorknob to prevent rotation of the knob, and which has an incorporated locking mechanism, requiring a separate key, again, on the same side of the door as the mechanism. 
     As is indicated from review of the referenced prior art, all of the mechanisms shown for disabling a doorknob require an additional locking mechanism, either with an incorporated lock and key, or by requiring a separate, external lock, which would require either a combination or key to open. None of the devices shown in the prior art allow the disabling function to be completed by simply placing the door ajar, fitting the device into place, and closing the door, thereafter allowing entry only by activation of the doorknob from the opposite side. Correspondingly, the devices of the prior art do not permit removal of the device, once locked in place, simply by opening the associated door from the opposite side and removing the device by simple reverse sequence of its installation, without the need to separately unlock a separate attached security device. 
     Accordingly, a need exists for a doorknob disabling device, of a two piece construction, which may be put in place in a simple sequence, by placing the associated door ajar, placing a cover over the doorknob and mating a retaining mechanism with the doorknob cover, by movement of the retaining mechanism toward the cover, and closing of the door, so that the cover and retaining mechanism may not be disassociated while the door is closed, because of the position of the associated door jam, and its contact with the retaining mechanism, and the associated doorknob and its contact with the cover. 
     A need for such a device is particulary apparent in industries such as the mobile home sales industry, to prevent prospective customers from unnecessarily opening, and leaving unlocked, different access doors, during the course of their investigation of the product. 
     Likewise, the prior art does not provide a doorknob disabling device which may be placed over a knob on a associated door, on the side for gaining entry, and closed by a person temporarily occupying the interior space to which the door provides access, when there is a need for personal security in such space. 
     The present invention is directed toward a device with a minimum of components and moving parts, which does not require a separate locking mechanism, and addresses the shortcomings of the prior art. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a locking device, generally, and, in particular, to a doorknob disabling device which is utilized with a standard doorknob, which may or may not have a key on the knob on the side of the door from which access may still be gained, and, in some cases, having a manual locking or unlocking device on the portion of the doorknob on the interior or opposing side of the door. The device may, however, be utilized on any doorknob, even one without locks on either side, to disable the doorknob from the side of the door on which the device is affixed, when the door is closed within its associated doorjamb. 
     The device is designed, primarily, to be utilized to cover the knob on the side of the door which does not require a key, and from which the door may be manually locked or unlocked, so that, when the door is closed, the door may only be unlocked, as a prelude to opening, by utilizing the key from the exterior side of the door. 
     The device may be constructed of an rigid, non-permeable material. It is ideally constructed of metal. Plastic, acrylic or other material may be utilized. The device consists of a hollow cylinder, cup, or other enclosure having an open end, in which to accept a doorknob, and being otherwise, externally closed. This member is constructed, generally, so that it has the appearance of a cylinder, glass, or cup, but, in theory, may be of any shape, so long as there is a unitary, rigid exterior surface, completely enclosing the doorknob, when the doorknob is inserted or covered through the open end. The enclosure may be of a variation of sizes, and is generally configured to fit as snugly as desired over a doorknob, so that the open end rests against the planar surface of the door upon which the knob is attached. The cylinder may be long enough to accommodate varying doorknobs while maintaining contact with the door. While the interior portion of the closed end of the covering enclosure may touch the outer surface of the doorknob when the open end of the enclosure is in contact with the planar surface of the door, it is not necessary that it do so, and the device works equally well when the interior of the enclosure is actually contacting the knob, or where there is a space between the exterior knob surface and interior surface of the enclosure. 
     The device may constructed in different sizes, to accommodate different diameters of doorknobs, but the device will operate as intended, so long as the interior portion of the enclosure is of greater diameter than the diameter of the doorknob. If desired, rings or spacers may be placed around the interior of enclosure to make the interior diameter of the enclosure more closely conform to the outer diameter of the knob, if a close fit is particularly desired. As stated, it is not necessary for this fit to be close in any particular relative dimension, other than that the space between the exterior circumference of the knob and the interior surface of the enclosure must be less than the distance of the insertion of the mating extension from the enclosure into the female mating receptacle on the retention device, so that sideways movement of the enclosure will be impeded by the knob, prior the point where the mating relationship may be disengaged. 
     The enclosure has an opening, which is basically formed by a truncated section, so that the opening has an edge surface, substantially in a singular plane, which corresponds with and contacts the planer surface of the associated door. Either in the same plane, or in a plane parallel thereto, the enclosure member has a mating extension which extends outward toward the outer edge of the door, when the enclosure is in place over the doorknob. 
     A second detachable retaining member is conformed to fit over the width of the door edge approximate to the where the doorknob and lock assembly to be disabled is located. The retaining member is, preferably, a flat piece, conformed by bending to contact, by corresponding planar surfaces, the side of the door on which the knob to be disabled is located, the opposing side of the door, and the exterior edge of the door extending between them. The retaining member is fitted with a receptacle member, to accept and rigidly contain the extension from the enclosure, in a male-female relationship, when the enclosure is placed over the doorknob, and the retaining member is then placed over the edge of the door as described. The portion of the retaining member which forms the female receptacle portion of the mating relationship may be a complete enclosure, or may be partially cut away leaving overlapping flanges at the edges to hold extension firmly in place. The portion of the retaining member which contacts the planar edge of the door also is conformed to provide an opening sufficient for the locking bolt of the doorknob locking assembly to pass through. 
     The device is put in place when the associated door is ajar. Accordingly, when the associated door is closed, within its associated doorjamb, the enclosure may not be removed from the doorknob, because disassociating motion along the plane of the door is prevented by contact between the interior of the enclosure and the doorknob assembly and contact by the exterior portion of the retention member, and the associated doorjamb. Further, the enclosure may not be moved away from contact with the door, around the doorknob, because of the portion of the retaining member which is bent around the edge of the door, and which contacts the opposite surface of the door, and because of the dual retaining function provided when the locking doorknob assembly bolt passes through the opening in the retention member and locks into the associated receptacle in the doorjamb. 
     In another embodiment of the invention, the enclosure member alternatively is provided with two parallel pairs of apertures, with each pair aligned linearly parallel to the surface of the associated door and perpendicular to the plane of the exterior edge of the door, with a corresponding parallel pair of rods mounted on the retention member and fitting within and through the parallel pairs of apertures in male-female relationship. 
     Other objects, advantages and novel features of this invention will be set forth and will become apparent in the detailed description which follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following detailed description is best understood with reference to the following drawings, in which: 
     FIG. 1 is a perspective view of the device, in mated position covering a doorknob and secured over the outer edge of an ajar door; 
     FIG. 2 is an exploded view of the components of the device showing the relationship between the device and an associated doorknob and door, as well as the mating association of the components of the device when in place; 
     FIG. 3 is a sectional top view of the device in place on an associated door; 
     FIG. 4 is perspective view of the an alternative embodiment of the device in place on an associated door, showing, in transparency, the relationship of the device with a doorknob on the associated door; 
     FIG. 5 is a sectional top-view of an alternative embodiment of the device in place on an associated door; and 
     FIG. 6 is a perspective view of the device, in mated position covering a doorknob and secured over the outer edge of a closed door. 
     FIG. 7 is a perspective view of the device in mated position covering a door knob and secured over the outer edge of a closed door, demonstrating the enclosure means in the shape if a truncated sphere. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The invention doorknob disabling device  10 , broadly considered, includes an enclosure member  20  and a retention member  30 . The doorknob disabling device is intended for use on an associated hinged door  40  having a doorknob assembly  41  which engages a locking bolt  42 . Such a door  40  generally has a planar interior surface  43  upon which the doorknob assembly  41  is mounted, a corresponding planar exterior surface  44  and a planar outer edge surface  45 , substantially perpendicular to the interior surface  43  and exterior surface  44 , and running between them. The locking bolt  42  extends from and retracts into the outer edge surface  45 , roughly proximate the doorknob assembly  41 . 
     Enclosure member  20  in the preferred embodiment is a hollow cylinder  21 , having a closed outer first end  22  and an open second end  23 . The cylinder  21  is truncated to form the open end  23 . Cylinder  21  has a rigid unitary outer surface  24  and a unitary inner surface  25 . The truncated open end  23  provides a continuous opening edge  26  of the outer surface  24  and inner surface  25  in a substantially singular plane as demonstrated in the cross-sectional views of FIGS. 3 and 5, which is proximate to and contacts the planar interior surface  43  of the associated door  40 . While the preferred embodiment of enclosure member  20  is a cylinder  21 , enclosure member  20  may be of varied exterior shapes, including, but not limited to, the shown cylinder  21 , a cup, or a truncated sphere, so long as the outer surface  24  is rigid and unitary, the edge  26  of the open end  23  is substantially planar, and the enclosure member  20  is sufficiently hollow to cover a doorknob  41  when the open end  23  is in contact with the associated door surface  43 , as shown in FIGS. 1,  2 ,  3 ,  4 ,  5  and  6 . 
     Attached to enclosure member  20  is a rigid mating extension  27 , extending outward from member  20  proximate to opening  23  and substantially parallel to the plane thereof. In the preferred embodiment of the invention, extension  27  is a flat bar member having an upper edge  27   a , a lower edge  27   b , defining a height A, and a first end  27   c  proximate to cylinder  21  and an outer second end  27   d , defining a length B. Extension  27  is of sufficient thickness or width  28  along its length B and height A to provide a rigid connection with retention member  30  when mated as shown in FIG.  1 . Extension  27  further has a flat outer surface  27   e  and a flat inner surface  27   f.    
     Retention member  30 , in the preferred embodiment, is a flat bar unit, having an outer surface  31  and an inner surface  32 . Member  30  is conformed in a substantial “u” shape to provide a first side  30   a , a second, parallel, opposing side  30   b , and a bridging, perpendicular end section  30   c . Member  30  if further conformed to fit over the edge  45  of associated door  40 , with the inner surface  32  of first side  30   a  in planar contact with interior surface  43 , inner surface  32  of opposing side  30   b  in planar contact with exterior surface  44 , and inner surface  32  of end section  30   c  in planar contact with outer edge surface  45 , when member  30  is moved into place as shown in FIGS. 1 and 2. 
     First side  30   a  of retention member  30  is further configured to receive mating extention  27  in a rigid coupling relationship as shown in FIG. 1, by relative contacting movement as shown in FIG.  2 . 
     Retention member  30  has an upper edge  33  and lower edge  34  defining a height dimension C. In the preferred embodiment, upper edge  33  and lower edge  34  are each flanged to traverse the width  28  of extension  27  along upper edge  27   a  and lower edge  27   b  and a portion of the length B of outer surface  27   e.    
     Extension member  27  and first side  30   a  are further conformed so that height dimension C is at least as long as height A, so that member  27  is slidably insertable within the flanged edges  33  and  34  and, when so inserted, is rigidly held there in a male-female relationship. 
     In another preferred embodiment the flanged ends  33  and  34  may be extended across height dimension C, and joined so that first side  30   a  of retention member  30  completely encircles extension member  27  when coupled in male-female relationship. Extension member  27  may be configured as a rod or other shape so long as first side  30   a  is correspondingly configured to provide a rigid male-female coupling when the outer second end  27   d  is fully inserted into the receptacle of first side  30   a . In whatever configuration or shape extension member  27  and the first side  30   a  of retention member  30  are provided, the mating movement between extension member  27  and first side  30   a  is substantially in a singular plane parallel to the plane of opening edge  26  and perpendicular to planar outer edge surface  45  of the associated door. 
     In the preferred embodiment, an opening  35  is also provided in end section  30   c  of retention member  30 . The opening  35  is provided large enough to permit passage through it of the locking bolt  42  when the locking bolt  42  is extended from outer edge surface  45 , as shown in FIG.  1 . 
     The device  10  is installed and made operative by placing the enclosure member  20  over the doorknob assembly  41  on the side of the associated door  40 , so that the open edge  26  is parallel to and in contact with the planar interior surface  43 , with the mating extension  27  extending outwardly and generally perpendicular to outer edge surface  45 . While the door  40  is ajar, retention member  30  is moved toward enclosure member  20 , until inner surface  32  of end section  30   c  is in planar contact with outer edge surface  45  of door  40 , and positioned so that locking bolt  42  is moveable through opening  35 , extension member  27  inserted within the flanged edges  33  and  34  of first side by doorjamb  50 . Any substantial movement of enclosure member  20  in direction E is prevented by doorknob assembly  41 , and movement of both enclosure member  20  and retention member  30  away from contact with the associated door  40  is prevent by the dual functions of bolt  42  extending through opening  35 , and the contact of inner surface  32  of opposing side  30   b  with exterior surface  44 . When the associated door  40  is opened and again ajar, the device may be removed by reverse sequence. 
     The entire device  10  may be constructed of metal or other rigid synthetic material such as plastic or acrylic matter. 
     An alternative embodiment of the device  10  is shown in FIGS. 4 and 5, wherein the mating function between enclosure member  20  and retention member  30  is provided by a pair of linear apertures  51  extending through enclosure member  20 , linearly aligned so as to be perpendicular to edge surface  45  above stem  41   a  of doorknob assembly  41 , and a corresponding second pair of apertures  52  extending through enclosure member  20  linearly aligned parallel to linear apertures  51  and in the same plane parallel to the plane of opening edge  23 , with the distance G between the corresponding pairs  51  and  52 , being less than the largest diameter H of doorknob assembly  41 . Retention unit  30  is correspondly conformed to provide the parallel rods  53  attached to side  30   a  with outer ends  53   a  and  53   b  linearly aligned to be insertable through aperture pairs  52  and  51 , respectively, when inner surface  32  of end section  30   c  contacts outer edge surface  45  with aperture  35  centered to allow passage by locking bolt  42 . Motion in directions E &amp; D is prevented in the same manner by doorjamb  50  and doorknob assembly  41 , while motion in direction F is additionally inhibited by contact of rods  53   a  and  53   b  against doorknob assembly  41 . 
     WHEREAS, a preferred embodiment of the invention has been illustrated and described in detail, it will be apparent that various and additional changes may be made in the disclosed embodiment without departing from the spirit of the invention.