Patent Publication Number: US-6662901-B1

Title: Ladder control apparatus

Description:
This is a continuation of U S. patent application Ser. No. 09/469,528, filed Dec. 22, 1999 now abandoned, which is a continuation of Ser. No. 09/016,911 filed Feb. 2, 1998 now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to apparatus for controlling the movement of a folding ladder or stairway, and more particularly, to an apparatus with a pivoted control arm to control the raising and lowering of a ladder or stairway of the type used in ceiling structures in a building. 
     2. Description of the Prior Art 
     Folding ladders or stairways are well known in the art and are frequently used in ceiling structures of buildings to provide access to attic space or upstairs rooms. Thus, these may be referred to as folding, disappearing attic ladders or stairways. Typically, such a ladder is mounted on a hinged door which fits in a framed opening in the ceiling. The ladder is folded and unseen when the door is closed and is unfolded to extend down to the floor when the door is open. 
     In one type of folding ladder, there are three ladder sections. A first section is fixedly attached to the door, a second section is hingedly connected at one end to the lower end of the first section, and a third section is hingedly attached to the other end of the second section. When folded, the second section is immediately adjacent to the first section, and the third section is immediately adjacent to the second section such that all sections are substantially parallel to one another. When unfolded, the sections are substantially aligned to form the ladder or stairway. Examples of such devices are manufactured by Bessler Stairway Company, Werner Co., American Stairways, Inc., The Marwin Company, and Davidson. Another example of such a folding stairway or ladder is shown in U.S. Pat. No. 2,649,237 to Bjorklund et al. These ladders usually are made of wood or metal, such as aluminum. The material of the ladder is unimportant to the present invention, however. 
     In these folding ladders, the door is pivotally connected at one end to a ceiling joist or other part of the building structure, and the other end of the door has a cable attached thereto which extends from the outer side of the door. The door is spring loaded to bias it toward a closed position. By pulling on the cord, the door is pivoted on the hinges and moved to an open, angularly disposed position with respect to the ceiling. The operator must then manually grasp the second or third section of the ladder to pivot the second and third sections downwardly to the unfolded operating position of the ladder. This is frequently difficult to do, particularly in high ceiling areas and for persons of short stature. The operator may have to jump up to grasp the ladder to unfold it. There is also some awkwardness in the fact that the spring tends to close the door while the operator is attempting to unfold the ladder. It is possible that the door may swing upwardly without warning while the operator&#39;s hand is extended into the ladder. Also, the ladder sections may pivot downwardly unexpectedly when lowering the ladder, causing one or more of the ladder sections to strike the operator. In fact, this latter problem has resulted in at least one fatality. All of these dangers are exacerbated if the operator has to jump to try to reach the ladder. 
     Therefore, there is a need for an apparatus to control the folding and unfolding of the ladder so that if a portion of the ladder pivots unexpectedly, the operator is at a safe distance from the ladder, thereby minimizing the possibility of injury. The present invention solves this problem by providing a ladder control apparatus with a pivoted control arm which allows the operator to manipulate the ladder sections while standing a safe distance from the ladder. Also, the operator can use both hands in a comfortable position to more positively control the movement of the ladder sections. 
     SUMMARY OF THE INVENTION 
     The ladder control apparatus of the present invention comprises a control base portion attachable to a folding ladder or stairway and a control arm portion pivotally connected to the base portion, whereby an operator of the apparatus may manipulate the ladder between folded and unfolded positions thereof while the operator is positioned away from the ladder. Preferably, the arm portion may be pivoted in substantially any direction with respect to the base portion, such as by connecting the arm portion to the base portion with a rod end pivot assembly or a ball and socket pivot assembly. 
     The apparatus further comprises means for retaining a distal or free end of the arm portion when the arm portion is not in use by the operator. In one embodiment, this means for retaining means comprises a spring biased clamp attachable to the ladder. The clamp resiliently retains the distal end of the arm portion. 
     In the preferred embodiment, the arm portion is a telescoping arm portion having a variably extended operating position. The apparatus further comprises locking means for locking the arm portion in a selected extended operating position. The locking means may comprise a locking ring and a rotatable collar adapted for compressing the locking ring. 
     Stated in another way, the apparatus of the present invention is adapted for controlling a folding ladder or stairway and comprises a base attachable to a section of the ladder and extending from a side rail thereof, and an arm having a proximal end pivotally attached to the base and a distal end by which an operator may exert pulling and pushing forces on the ladder to move it between folded and unfolded positions thereof The arm comprises an outer arm portion and an inner arm portion telescopingly received in the outer arm portion. 
     The present invention also includes a ladder apparatus for use in an opening in a building structure. The ladder apparatus comprises a plurality of ladder sections substantially parallel to one another when in a folded position and substantially aligned with one another when in an unfolded position. Each of the ladder sections has a pair of spaced side rails and a plurality of treads extending between the side rails. One of the ladder sections is adapted for pivotal connection with respect to the building structure adjacent to the opening therein. This ladder apparatus further comprises a control base attached to another of the ladder sections, and a control arm having a proximal end pivotally attached to the control base and a distal end adapted for gripping by an operator whereby force may be applied to the other of the ladder sections to move the ladder between folded and unfolded positions thereof The arm may be pivoted with respect to the side rail of the other of the ladder sections. 
     The ladder apparatus may further comprise a clamp attached to the other of the ladder sections and spaced from the control base. The clamp is adapted for grippingly retaining the distal end of the arm in a stored position when the arm is not in use by the operator. 
     The arm of the ladder apparatus comprises an outer arm portion and an inner arm portion telescopingly received in the outer arm portion such that a length of the arm may be selectively varied by the operator. A lock may be provided for locking the inner and outer arm portions with respect to one another when the arm is at a desired length. The lock may comprise a locking ring extending from the outer arm portion and disposed around the inner arm portion, and a collar threadingly connected to the locking ring. The collar is adapted for compressing the locking ring into locking engagement with the inner arm portion when the collar is rotated with respect to the outer arm portion. Other locking arrangements could also be used. 
    
    
     Numerous objects and advantages of the invention will become apparent as the following detailed description of the preferred embodiment is read in conjunction with the drawings which illustrate such embodiment. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows the ladder control apparatus of the present invention in a storage position on a folding ladder or stairway which is in a stored or closed position. 
     FIG. 2 illustrates the ladder control apparatus in an extended operating position with the ladder in a partially open position. 
     FIG. 3 illustrates the ladder control apparatus in the extended operating position and the ladder in an unfolded operating position. 
     FIG. 4 illustrates a front view of the ladder in the operating position of FIG.  3 . 
     FIG. 5 is an enlarged front view of a portion of the ladder with a preferred embodiment of the ladder control apparatus thereon. 
     FIG. 6 shows an alternate embodiment of the ladder control apparatus. 
     FIG. 7 is a section of the ladder taken along lines  7 — 7  in FIG.  1 . 
     FIG. 8 shows a cross section taken along lines  8 — 8  in FIG.  5  and showing details of a lock for holding the ladder control apparatus in a selected extended position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, and more particularly to FIGS. 1-4, a preferred embodiment of the ladder control apparatus of the present invention is shown and generally designated by the numeral  10 , in position on a folding or disappearing ladder  12  which may also be referred to as a folding or disappearing stairway  12 . 
     Ladder  12  is of a kind generally known in the art and is adapted to fit and operate within an opening.  14  defined in a ceiling structure  16  of a building and above a floor surface  17 . Opening  14  is generally formed by a rectangular frame  18  comprising a pair of parallel longitudinal members  20  interconnected by a pair of parallel transverse members  22 . 
     In the illustrated embodiment of ladder  12 , the ladder comprises a first ladder section  24 , a second ladder section  26  and a third ladder section  28 . However, the number of ladder sections is not critical to the invention, and no particular number of ladder sections is required. 
     First ladder section  24  is constructed with a pair of longitudinally extending side rails  30  interconnected by a plurality of transversely extending treads or steps  32 . Similarly, second ladder section  26  has a pair of longitudinally extending side rails  34  interconnected by a plurality of transversely extending treads or steps  36 , and third ladder section  28  has a pair of longitudinally extending side rails  38  interconnected by a plurality of transversely extending treads or steps  40 . 
     First ladder section  24  is fixedly attached to a door  42  which extends across opening  14  when the door and ladder  12  are in the closed position shown in FIG.  1 . Door  42  is pivotally connected to one of transverse members  22  of frame  18  by a hinging means such as a piano hinge  44 . Springs (not shown) also interconnect door  42  and longitudinal member  20  to bias door  42  toward the closed position in a manner known in the art. 
     Second ladder section  26  is pivotally connected to an end of first ladder section  24  opposite hinge  44  by hinges  46  which are attached to side rails  34  and  30 , respectively. Similarly, third ladder section  28  is pivotally connected to the opposite end of second ladder section  26  from hinges  46  by hinges  48  which are attached to side rails  38  and  34 , respectively. Some ladders have hinges on the inside as well as the outside of the side rails. 
     The length of third ladder section may be cut to accommodate less vertical space between the ceiling and floor as illustrated by a different floor surface  17 ′ shown in phantom lines in FIG.  3 . 
     A hand rail  50  is attached to one of side rails  30  of first ladder section  24 . For clarity, hand rail  50  is shown only in FIG.  3 . 
     A cable  52  extends downwardly from the end of door  42  opposite hinges  44 . Cable  52  is used to pull on door  42  to open it when it is desired to utilize ladder  12 . 
     Ladder control apparatus  10  comprises a control base  54  preferably disposed on one of side rails  34  of second ladder section  26  adjacent to hinges  48 . As seen in FIG. 5, control base  54  has a threaded stud portion  55  extending through the side rail. Stud portion  55  is attached to side rail  34  by a fastening means of a kind known in the art such as nut  56 . Control base  54  also has a shaft portion  57  extending away from the outside of side rail  34 . 
     A proximate end of a control arm portion  58  of apparatus  10  is connected to base portion  54  by a pivot assembly  60 . In the embodiment shown in FIG. 5, pivot assembly  60  is a rod end pivot assembly  60  of a kind known in the art and having a body  61  and a bushing  62 . Body  61  is attached to the distal end of control arm  58  by a stud  63  or other fastening means. 
     Bushing  62  is disposed around shaft portion  57  of control base  54  and this allows control arm  58  to be rotated freely about shaft portion  57  as shown in FIGS. 2,  3  and  5 . 
     Bushing  62  of rod end assembly  60  is disposed within a curvilinear surface  64  in body  61 , and as seen in phantom lines in FIG. 5, this also allows pivotation of control arm  58  angularly with respect to shaft portion  57  of control base  54  away from side rail  34  of second ladder section  26 . 
     FIG. 6 shows an alternate embodiment of ladder control apparatus  10 ′ comprising a control base  54 ′ connected to control arm  58  by an alternate pivot assembly  60 ′. Control base  54 ′ has a threaded stud portion  55 ′ which extends through ladder side rail  34  and is attached by a fastening means such as nut  56 . Pivot assembly  60 ′ is a ball and socket pivot assembly  60 ′ of a kind known in the art and having a ball  65  in a socket  67  defined in a body  69 . Ball  65  can be integrally formed on control base  54 ′. Body  69  is attached to control arm  58  by a stud  71  or other fastening means. Ball and socket pivot assembly  60 ′ allows rotation of control arm  58  in the same manner shown in FIGS. 2,  3  and  5  for the first embodiment and further allows pivotation of the control arm away from side rail  34  angularly with respect to control base  54 ′, as seen in FIG.  6 . 
     Those skilled in the art will see that either rod end pivot assembly  60  or ball and socket pivot assembly  60 ′ allows control arm  58  to be pivoted in substantially any direction with respect to base  54  or  54 ′ such as shown in FIGS. 2,  3  and  5  and also in phantom lines in FIGS. 5 and 6. Other types of pivot assemblies could also be used, and the invention is not intended to be limited to a rod end or ball and socket pivot. 
     Further, while apparatus  10  is shown attached to second ladder section  26 , it could be mounted on a different part of ladder  12 , such as third ladder section  28 , if desired. 
     Control arm  58  has a telescoping configuration with an inner arm portion  66  telescopingly or slidingly received in an outer arm portion  68 . Thus, control arm  58  has a variable extended operating position 
     When ladder control apparatus  10  is not in use, a distal end of inner arm portion  66  of control arm  58  may be retained in a storage position against ladder  12  by a retaining means, such as a clamp  70  attached to an end of side rail  34  of second ladder section  26  adjacent to hinges  46 . See FIGS. 5 and 7. Clamp  70  has a generally U-shaped configuration defining a gap  72  which opens downwardly in the storage position of FIG.  1 . Clamp  70  is preferably made of a resilient material such as spring steel, so that gap  72  is biased to a size slightly smaller than the outside diameter of inner arm portion  66 . Inner arm portion  66  may be forced into gap  72  to spread clamp  70  slightly to place the inner arm portion in the stored position shown in FIGS. 1 and 7. The spring-like action of clamp  70  thus grippingly retains inner arm portion  66  therein until forced out by an operator of ladder control apparatus  10 . 
     Referring to FIGS. 5 and 8, inner arm portion  66  may be locked with respect to outer arm portion  68  of control arm  58  by a lock  74 . Lock  74 , as illustrated, comprises a locking ring  76  which may be attached to, or integrally formed with, the distal end of outer arm portion  68 . One or more longitudinally extending slots  78  are defined in locking ring  76 . A locking collar  80  is engaged with locking ring  76  at threaded connection  82 . Threaded connection  82  tapers slightly so that as locking collar  80  is threaded onto locking ring  76 , the collar squeezes the locking ring to reduce the width of slot or slots  78 . This squeezing action lockingly reduces the inside diameter of locking ring  76  and engages it against inner arm portion  66 . This locking operation may be utilized at any relative position of inner arm portion  66  with respect to outer arm portion  68 , and thus it may be said that lock  74  provides a means for locking inner arm portion  66  in a particular extended operating position with respect to outer arm portion  68 . Other means for locking a telescoping connection could also be used. 
     OPERATION OF THE INVENTION 
     Assuming that ladder  12  is in the folded position shown in FIG. 1 with door  42  closed, the first step in utilizing the ladder is to pull on cable  52  to pivot door  42  on hinge  44  with respect to opening  14 . Once door  42 , and thus ladder  12 , are partially pivoted, the operator may free the distal end of inner arm portion  66  of control arm  58  from clamp  70 , rotate the control arm and extend the inner arm portion with respect to outer arm portion  68  to lengthen control arm  58  as desired. Control arm  58  is easy to reach because the distal end of inner arm portion  66  is originally near the bottom of the folded ladder  12 . See FIG.  2 . 
     After this, lock  74  is engaged to lock inner arm portion  66  with respect to outer arm portion  68  as previously described. 
     The operator may further manipulate control arm  58  with respect to control base  54  and ladder  12  as desired. One or two hands may be used. The length of control arm  58  allows the operator to control movement of ladder  12  from a position safely away. With pivot assembly  60  or  60 ′, but not by way of limitation, control arm  58  can also be pivoted laterally away from side rail  34  of second ladder section  26  as previously described so that the operator can stand to one side of ladder  12 . Thus, unexpected pivotation of second ladder section  26  and/or third ladder section  28  is prevented or will not result in the ladder sections striking the operator. By manipulating control arm  58 , ladder  12  may be moved from the original folded storage position to a partially unfolded position as seen in FIG.  2  and eventually to the unfolded operating position shown in FIG.  3 . 
     Because ladder control apparatus is attached to second ladder section  26 , those skilled in the art will see that the movement of the second ladder section is completely controlled by the operator, and thus the movement of third ladder section  28  is also controlled. Even if second ladder section  26  and/or third ladder section  28  were somehow to unexpectedly pivot either together or individually, the invention allows the operator to be standing away from ladder  12  because of the degree of control provided by ladder control apparatus  10  or  10 ′. However, such unexpected movement is unlikely when ladder control apparatus  10  or  10 ′ is operated properly. 
     With ladder  12  in the operating position shown in FIG. 3, lock  74  may be disengaged and inner arm portion  66  telescoped within outer arm portion  68  so that the distal end of the inner arm portion may be reengaged with clamp  70  to hold control arm  58  in its storage position as shown in FIG. 4 during use of the ladder. 
     When it is desired to raise ladder  12  back to its folded storage position, the procedure described above is simply reversed. 
     It will be seen, therefore, that the ladder control apparatus of the present invention is well adapted to carry out the ends and advantages mentioned as well as those inherent therein While presently preferred embodiments of the apparatus have been shown for the purposes of this disclosure, numerous changes in the arrangement and construction of parts may be made by those skilled in the art. All such changes are encompassed within the scope and spirit of the appended claims.