Abstract:
The present disclosure is concerned with an improved latching mechanism for the hinged section of a ceiling track for traveling curtains. The latching mechanism is designed to make a readily audible sound when it is locked. It is based upon a generally oval shaped lock knob which passes through a generally oval shaped aperture in the bottom wall of a receiver for the lock knob. The aperture is designed so that when the lock knob is rotated its long axis no longer aligns with the long axis of the aperture it can no longer pass through the aperture. The bottom wall of the receiver carries two upwardly extending side walls that must be pushed outward to allow the passage of the lock knob as it rotates and that carry gaps that accommodate the tips of the lock knob and allow the side walls to move back toward their undeformed position.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to ceiling mounted curtain tracks which have hinged sections which facilitate the loading and unloading of curtains by allowing easier access to the track and to an improved locking mechanism which releases and secures the hinged section&#39;s alignment with the balance of the track to which it is hinged. 
       BACKGROUND OF THE INVENTION 
       [0002]    Ceiling mounted curtain tracks have been adopted for a variety of uses including travelling curtains such as those used in hospitals to establish privacy for certain spaces such as the area around a patient&#39;s bed. But the loading and unloading of curtain carriers posed a difficulty because these tracks were adjacent to the ceiling and access to them frequently required a ladder or stepstool which in turn posed a safety risk. 
         [0003]    A system was developed in which a portion of the curtain track was hinged so that it could swing down from the ceiling and provide easier access. Curtains attached to carriers adapted to be loaded on the curtain track could be more easily suspended from or removed from such ceiling tracks by sliding these carriers on to the hinged section which had been lowered. Once the curtains were thus loaded onto the lowered hinged section, it could be swung into alignment with the rest of the track and a portion of the carriers from which the curtains were suspended could be slid on to the rest of the track by grasping the suspended curtains without the necessity of being adjacent to the ceiling. Such an approach is described in U.S. Pat. No. 4,599,763. 
         [0004]    However, such an approach required a mechanism to secure the hinged section when it was in alignment with the balance of the track and a latching mechanism was developed which interacted with a fixed bracket as described in the above mentioned patent. Persons operating this latching mechanism while standing on the floor faced in accordance with its intended use faced some difficulties. Among others it was not easy to tell if the mechanism had been locked against release of the hinged section and the mechanism did not always readily latch when the hinged section was brought into contact with the fixed bracket. 
         [0005]    Therefore there was a need for a locking mechanism which functioned in this environment in a simple and reliable manner to lock and release the hinged section and give a clear and unambiguous indication when the mechanism was locked to the fixed bracket. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention involves a simple but elegant lock mechanism which functions to secure and release a hinged section of a ceiling track for traveling curtains based on the interaction of a generally oval shaped lock knob with a receiver with a generally oval shaped aperture and elastically deformable side walls, each of which has a gap in which a tip of the lock knob located at the end of its long axis can seat when the lock knob is rotated such that its long axis is generally perpendicular to the long axis of the oval shaped aperture. These side walls are spaced from the axis of rotation of the lock knob such that they are elastically forced outward by the tips of the lock knob as the lock knob rotates from having its long axis parallel to the long axis of the aperture in the bottom wall of the receiver to having its long axis perpendicular to the long axis of this aperture and having these tips seated in the gaps in these walls. The gaps are configured such that when the tips seat in them, these tips project into these gaps allowing at least a partial relaxation of the elastic deformation of the sidewalls. The side walls are constructed such that when the tips seat in the gaps and at least a portion of this elastic deformation is relieved an audible sound is produced. In a preferred embodiment, the lock knob has a ring spaced downwardly from the bottom of its generally oval shaped portion which has a size such that it will not pass through the aperture and has an upper surface which engages the bottom surface of the bottom wall of the receiver. It is spaced from the bottom surface of the generally oval shaped portion of the lock knob to define a gap which accommodates the bottom wall of the receiver when the lock knob is rotated such that its long axis is not aligned with the long axis of said aperture. It is also preferred that the lock knob have a downwardly depending cylindrical shaft about which it rotates. In a particularly preferred construction this shaft connects the oval upper portion of the lock knob to its lower ring and has a diameter which will pass through the aperture. 
         [0007]    In a preferred embodiment, the lock knob is rotationally affixed to a flange which is in turn affixed to the hinged section of the ceiling track. In a particularly preferred embodiment, a shaft passes through an aperture in this flange and is secured to the lock knob. It is especially preferred that the lock knob have a recess in its bottom surface into which the top of this shaft is seated. 
         [0008]    In a preferred embodiment, the side walls of the receiver are constructed of an injection moldable polymer. In a particularly preferred embodiment, the side walls are so constructed that rotating the lock knob from a locked position with its tips seated in the gaps of the side walls to an open position in which its long axis is aligned with the long axis of the aperture in the bottom wall of the receiver and the lock knob can pass through this aperture is within the manual capacity of an average person. In an especially preferred embodiment, the sidewalls have partial gaps between their lower edges and the bottom wall of said receiver to reduce the amount of force (or torque) necessary to deflect these walls outward to allow full rotation of the lock knob. In a preferred implementation of this approach, these horizontal gaps run from the vertical gaps in which the tips of the lock knob seat part way to where they join the other side walls of the receiver which cross the long axis of the aperture of the bottom wall of the receiver. 
         [0009]    In a further preferred embodiment, the gaps in the side wall interact with the tips of the lock knob so that it is readily apparent that these tips have seated in these gaps. This typically involves these tips projecting out of these gaps and being of a distinctive color which contrasts with that of the side walls carrying the gaps. It also involves the placement and orientation such that these gaps and the tips projecting through them are readily visible to a person operating the lock mechanism while standing on the floor. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of the hinged or lowerable and permanently affixed sections of the ceiling track joined by a hinge with the hinged section terminating in a connector to which a lock knob is affixed with the key of a control wand being inserted into the bottom of the lock knob. Also illustrated is a receiver for the lock knob which is adapted to be mounted on a wall. 
           [0011]      FIGS. 2A and 2B  are perspective views of the lock knob showing the top and bottom of its bottom ring feature, respectively. 
           [0012]      FIG. 3  is a top plan view of the lock knob 
           [0013]      FIG. 4  is a side elevation of the lock knob with dashed lines showing internal structure. 
           [0014]      FIG. 5  is a side elevation of the bottom fastener for the lock knob. 
           [0015]      FIG. 6  is a side elevation of the lock knob affixed to the horizontal flange of the connector. 
           [0016]      FIG. 7  is a side elevation of the lock knob receiver adapted for wall mounting. 
           [0017]      FIG. 8  is a top plan view of the lock knob receiver. 
           [0018]      FIG. 9  is a perspective view of the lock knob receiver adapted to mount to a ceiling structure. 
           [0019]      FIG. 10  is a top elevation of the lock knob inserted through the generally oval aperture of its receiver and affixed to the connector which is in turn affixed to the hinged section of the ceiling track. 
           [0020]      FIG. 11  is a top elevation of the lock knob inserted through the generally oval aperture of its receiver and rotated 90°. It is also affixed to the connector which is in turn affixed to the hinged section of the ceiling track. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    The present invention is concerned with a latching mechanism for a hinged section of a ceiling track for travelling curtains which can be lowered or raised by a person standing on the floor beneath the ceiling track using a wand which interacts with the latching mechanism. The latching mechanism should function such that there is no ambiguity as to when it is locked and should be easy to operate. It should be capable of being operated numerous times without any noticeable deterioration in its operation. It is preferred that it be constructed of injection moldable parts. 
         [0022]    The latching mechanism comprises a generally oval shaped lock knob which is preferably rotatably attached to the hinged section and a receiver which has a generally oval shaped aperture in its bottom wall adapted to receive the lock knob and gapped side walls to restrain the lock knob from rotation when the tips at the ends of the long axis of the lock knob are seated in the gaps of these side walls. The gaps in the side walls are preferably placed such that these tips seat in theses gaps when the lock knob has been rotated so that its long axis is approximately perpendicular to the long axis of the aperture in the bottom wall of the receiver. The side walls themselves are preferably constructed of an elastically deformable material and are spaced such that the tips at the ends of the long axis of the lock knob force them outward when the lock knob is rotated. These tip interact with the side walls such that when these tips seat in the gaps in these sidewalls, the side walls relax inward toward the axis of rotation of the lock knob and in so doing produce a readably audible sound. It is preferred that these tips protrude through these gaps so as to be visible when viewing the outside of these side walls. This visibility may preferably be enhanced by giving these tips a distinctive color which contrasts with the exterior surfaces of these side walls. 
         [0023]      FIG. 1  illustrates the latching mechanism in its operating environment. A ceiling track  10  is comprised of a section  12  which is adapted to be affixed to a ceiling, a section  14  which is adapted to be lowered to facilitate the loading and unloading of curtains onto the track and a hinge  16  which joins the two sections  12  and  14 . As illustrated the operation of this latch is unrestrained and simply allows the section  14  to rotate into and out of alignment with the section  12 . Section  14  has a connector  17  affixed to its end distal from the hinge  16  and this connector in turn has a flange  18  which extends beyond the end of the distal end of the section  14 . A lock knob  22  is rotatably secured to this flange  18 . A wand  19 , useful to rotate the lock knob  18 , carries a key  20  which is capable of interlocking with the lock knob  22  to transmit rotation from the wand  19  to the lock knob  22 . A receiver  24  is capable of being secured to a wall via downwardly extending flange  25  which carries screw holes  27  which can be used to secure the receiver  24  at a position that when retaining the lock knob  22 , it holds the section  14  in horizontal alignment with section  12 . 
         [0024]      FIGS. 2 through 4  illustrate details of the construction of the lock knob  22 . It has a lower ring  26  which is spaced downwardly from its generally oval shaped main body which has two wings  28  which extend along its long axis. This ring has a top surface  29  which will interact with the bottom surface of the bottom wall of the receiver. The each of the wings  28  has a bottom surface  30  which will interact with the top surface of the bottom wall of the receiver and a tip  32  which will interact with a side wall of the receiver. The top surface  29  and the bottom surface  30  define a gap  34  which will accommodate the bottom wall of the receiver. The bottom of the lock knob  22  has a centered cylindrical recess  31  which at its upper end terminates in a rectangular recess  33 . These recesses are adapted to accommodate the bottom fastener  44  for the lock knob which is illustrated in  FIG. 5 . 
         [0025]      FIG. 5  illustrates the bottom fastener  44  for the lock knob. It has a lower cylindrical body portion  45 , an upper cylindrical body portion  47  with a smaller diameter than that of the lower portion  45  and it carries a rectangular body portion  49 . The upper cylindrical portion  47  is adapted to closely fit within the recess  31  of lock knob  22  while the rectangular body portion  49  is adapted to closely fit within the recess  33  of the lock knob  22 . The bottom of the lower portion carries a receptacle  51  which accommodates the key  20  of the wand  19  (illustrated in  FIG. 1 . 
         [0026]      FIG. 6  illustrates the lock knob  22  rotatably secured to the flange  18  of the connector  17 . The flange  18  has a circular aperture (not illustrated) through which the upper cylindrical portion  47  of the bottom fastener  44  passes. This portion  47  is mechanically secured to the lock knob  22  such that they will rotate together. The lower portion  45  of the bottom fastener  44  has a larger diameter than the aperture in the flange  18  of the connector  17 . It cooperates with the bottom ring  26  of the lock knob to secure the lock knob  22  to the flange  18 . The receptacle  51  which accommodates the key  20  of the wand  19  (illustrated in  FIG. 1 ) is adapted to transmit rotation from the wand  20  to bottom securing member  44  and, in turn, the lock knob  22 . The connector  17  carries ribs  21  which reinforce its connection with its flange  18 . 
         [0027]      FIGS. 7 and 8  illustrate details of the construction of the receiver  24 . It has two side walls  36 , each of which has a gap  38 . These side walls  36  are attached to a bottom wall  37  and to end walls  39 . The bottom wall  37  has an aperture  40  adapted to accommodate the top generally oval shaped portion of the lock knob  22 . There is a gap  42  beneath each of the side walls  36  which partially interrupts its connection with the bottom wall  37  and lessens the amount of force or torque necessary to deflect these walls outward and allow the rotation of the lock knob  22  when it is engaged with the receiver  24 . As also illustrated in  FIG. 1  it carries a downwardly extending flange  25  which is adapted to affix the carrier  24  to a wall adjacent to the ceiling. 
         [0028]      FIG. 9  illustrates an alternative embodiment of the receiver  24  which carries flanges  46  which are adapted to secure the receiver  24  to a ceiling structure 
         [0029]      FIGS. 10 and 11  illustrate the operation of the lock knob  22  with the carrier  24 . In  FIG. 9  the lock knob  22  is in an unlocked position and is able to pass through the aperture  40  in the bottom wall  37  of the receiver  24 . The hinged section  14  is attached to the connector  17  via rivets  23 . The flange  18  of the connector  17  carries the lock knob  22  as illustrated in  FIG. 5 . In  FIG. 10  the lock knob  22  is in a locked position and is unable to pass through the aperture  40  in the bottom wall  37  of the receiver  24 . The tips  32  of the lock knob  22  protrude in the gaps  38  in the side walls  36  of the receiver  24  and restrain the lock knob  22  from rotation. The application of a sufficient amount of torque to the wand  19  (illustrated in  FIG. 1 ) will cause the side walls  36  to deflect outward away from the axis of the lock knob  22  as they are pressed upon by the tips  32  of the lock knob  22 . In the locked position shown in  FIG. 10 , the bottom surfaces  30  of the wings  28  of the receiver  22  (Illustrated in  FIGS. 2B and 4 ) engages the top surface of the bottom wall  37  of the receiver  24  to support the connector  17  and the hinged section  14  of the ceiling track  12  (illustrated in  FIG. 1 ) against downward movement. The top surface  29  (illustrated in  FIGS. 2A ,  3  and  4 ) of the bottom ring  26  (illustrated in  FIGS. 2A ,  2 B,  4  and  5 ) interacts with the bottom surface of the bottom wall  37  of the receiver  24  to limit the upward travel of the lock knob  22  through the aperture  40  in the bottom wall  37  of the receiver  24  in the locked or unlocked position. The tips  32  of the lock knob  22  interact with the side walls  36  of the receiver  24  such that when these tips seat in the gaps  38  of the side walls  36  a readily audible sound is produced. This is a function of the material of which the side walls  36  are constructed and the distance that they move inward toward the axis of rotation of the lock knob  22  when the tips  32  seat in the gaps  38 . The tips  32  are given a red color while the side walls  36  are white to facilitate visual detection of the tips  32  projecting into the gaps  38 . 
         [0030]    It is preferred for ease of manufacturability and minimization of cost that as many of the elements of the latching mechanism as possible be made of injection moldable polymer. It is particularly preferred that the lock knob, receiver and connector be injected molded. 
         [0031]    It is preferred to construct both the side walls of the receiver and at least the tips of the lock knob of polymers which have a reasonably low coefficient of friction but also have a good resistance to frictional wear such that the tips slide smoothly over the inside surface of the side walls and can do so many times without any significant wear being apparent. It is also preferred to construct the side walls of the receiver of a polymer which will sustain a deflection of at least about 0.10 of an inch but still have a reasonable degree of resistance to deflection. It is particularly preferred to use a polymer with a flexural modulus of at least about 350,000 psi as determined by ASTM D790. The well known thermoplastic engineering resins are preferred. The acetal resins are particularly preferred as displaying a good balance of cost, formability and mechanical properties. 
       WORKING EXAMPLE 
       [0032]    A latching mechanism was constructed in accordance with  FIGS. 1-9  by injection molding CP Pryme® Acetal AC 100-9, a polyoxymethylene polymer with a flexural modulus of about 377,000 psi. The side, end and bottom walls of the receiver were 0.125 inches thick. The inside surfaces of the side walls were spaced 1.12 inches apart while the vertical gaps where 0.30 inches in width and the horizontal gaps beneath the side walls was 0.080 inches high and extended 0.40 inches from the vertical gaps towards the end walls. The distance from where the side walls joined the end wall distal from the downwardly extending flange of the receiver to the vertical gaps was 0.6 inches while the distance from the juncture with the end wall proximate to this flange was 0.788 inches. The aperture in the bottom wall of the receiver was roughly elliptical (or Oval) in shape with a long axis of 1.417 inches and a short axis of 0.90 inches with its short axis centered in the vertical gaps. The ends of the long axis had a radius of 0.248 inches and the ends of the short axis had a radius of 0.448 inches. 
         [0033]    The lock knob had a long axis of 1.22 inches and a short axis of 0.875 inches. The radius at the ends of the long axis was 0.188 inches and the radius at the ends of the short axis was 0.875 inches. The radius of the bottom ring was 1.063 inches. The distance between the bottom of the wings of the generally oval shaped portion of the lock knob and the top of the circular ring was 0.150 inches. The ring was 0.150 inches high and the complete lock knob was 0.850 inches high. The lock knob had a centered circular recess with a diameter of 0.520 inches and a height of 0.250 inches which was surmounted by a rectangular recess 0.125 inches high, 0.471 inches long and 0.208 inches wide. 
         [0034]    A bottom securing member with an upper cylindrical section 0.497 inches in diameter and 0.425 inches high was permanently positioned into the cylindrical recess in the bottom of the lock knob. The top of this cylindrical section carried a centered rectangular section 0.150 inches high, 0.445 inches long and 0.197 inches wide. This bottom securing member had a bottom securing member 1.0 inches in diameter and 0.750 inches high. It passed through an aperture in the flange of the connector which was 0.520 inches in diameter. This flange was 0.125 inches thick. 
         [0035]    The lock knob was red and the side walls of the receiver were white. 
         [0036]    The lock knob passed easily through the aperture in the bottom wall of the receiver and was repeatedly rotated until its tips seated in the vertical gaps and then rotated back so that it could pass through the aperture in the bottom wall of the receiver. The rotation in either direction was well within the digital capacity of the average person. Each time these tips seated in the vertical gaps a readily perceived click was heard and the red tips were readily visible when viewing the vertical gaps. When the tips were seated in the gaps the connector was securely held against any downward movement. 
         [0037]    While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.