Patent Publication Number: US-6711760-B1

Title: Self-lock hub unit of lower frame of a foldable playyard

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a foldable playyard and more particularly, to an improved self-lock hub unit of lower frame of a foldable playyard. 
     BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 6,305,037 has disclosed a lower frame structure of a foldable playyard, which included a hub assembly. As illustrated in FIG. 11, the hub assembly included a substantially hollow cylindrical body  110 , four coupling portions  112   a-d  spaced apart from each other and non-axially extending outwardly from the hub body for receiving hub legs, and locking means rotatably coupled the hub body for operablely cooperating with the coupling portions to lock the hub legs in an erected position, wherein each of the coupling portions comprises a reversed U-shaped cross-section, an elongated slot formed in both side walls thereof, and an opening formed in a top wall thereof. 
     The locking means included a bias spring  120  disposed in hub body; a latch member  130  rotatably coupled to the hub body and arranged such that it is biased toward a lock position by the bias spring, wherein the latch member has two substantially L-shaped arms formed at two substantially positions of a lower face of a periphery portion thereof and each of the L-shaped arm has a vertical portion and a horizontal portion which will be inserted into the slots of corresponding coupling portion of the hub body as the latch member is biased toward the lock position by the bias spring to lock the hub legs in the erected position; and a knob  140  coupled to the latch member to turn the latch member toward an unlock position such that the horizontal portion of the L-shaped arm withdrawn from the slot and the hub legs may pivot from the erected position to the collapsed position. 
     Although the hub assembly  10  disclosed in the above-mentioned &#39;037 is able to perform a locking/unlocking function of the lower frame of the playyard, it is inconvenient to perform the unlocking operation because it takes two steps to do it, i.e., first turn the knob and then lift the hub assembly, and thus may cause confusion. 
     SUMMARY OF THE INVENTION 
     Accordingly, the object of the present invention is to provide an improved self-lock hub unit of a lower frame of a foldable playyard, of which the locking/unlocking operation may be performed in one step. 
     To achieve this and other advantages and according to the purpose of the present invention, as embodied and broadly described, the hub unit of the lower frame of the playyard includes a body having a plurality of slots formed at a periphery thereof for receiving tube legs of the playyard and a vertical cavity formed at the center thereof; an actuating member which is vertically movably received in the central cavity; two sliding engaging assemblies movably mounted two oppositely positioned tube legs respectively, each sliding engaging assembly having a first member, a second member coupled to the first member for movably coupling the first member to one of the tube legs, and a biasing member disposed in the tube leg to bias the first and second members toward an open end of the tube leg, wherein the two oppositely positioned tube legs are rotatably received in two radially opposite slots of the body respectively; two locking means formed on the body at positions corresponding to the sliding engaging assemblies respectively and having a guiding portion and an engaging portion; and a strap coupled to the actuating member; wherein the actuating member, the sliding engaging assemblies, and locking means are arranged such that while the tube legs are rotated from vertical position to horizontal position, the second member of the sliding engaging assembly will contact with and guided by the guiding portion of the locking means to engage with the engaging portion of the locking means and thereby locking the tube legs in horizontal position with at least one portion of the first member of the sliding engaging assembly protruding into the central cavity; and while the actuating member is moved upward by pulling the strap, the actuating member will engage with the at least one portion of the first member that protruding into the cavity and push the first member to cause the second member disengaging with the engaging portion of the locking means. 
     According to another embodiment of the present invention, a self-lock hub unit of a lower frame of a playyard comprises a body having a plurality of slots formed at a periphery thereof for receiving tube legs of the playyard and a rectangular recess formed at the center portion and defined by two opposite long-side walls and two short-side walls; two guiding plates disposed at the central portion of the recess and parallel with the short-side walls, the guiding plates being arranged such that they are spaced apart from each other so as to define a cavity therebetween; an actuating member which is movably received in the cavity; two sliding engaging assemblies movably mounted two oppositely positioned tube legs respectively, each sliding engaging assembly having a first member, a second member coupled to the first member for movably coupling the first member to one of the tube legs, and a biasing member disposed in the tube leg to bias the first and second members toward an open end of the tube leg, wherein the two oppositely positioned tube legs are rotatably received in two radially opposite slots of the body respectively; two locking means formed on the body at positions corresponding to the sliding engaging assemblies respectively and having a guiding portion and an engaging portion; and a strap coupled to the actuating member, wherein the actuating member, the sliding engaging assemblies, and locking means are arranged such that while the tube legs are pivoted from a vertical position to a horizontal position, the second member of the sliding engaging assembly will contact with and guided by the guiding portion of the locking means to engage with the engaging portion of the locking means and thereby locking the tube legs in an erected position; and while the actuating member is moved upward by pulling the strap, the actuating member will push the second member to disengage with the engaging portion of the locking means. 
     Additional features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings, 
     FIG. 1 is a perspective view of a self-lock hub unit according to a first embodiment of the present application, 
     FIG. 2 is a partial sectional, exploded perspective view of the self-lock hub unit according to the first embodiment of the present application, 
     FIG. 3 is a cross-section view of self-lock hub unit according to the first embodiment of the present application, which illustrates the tube legs are in a locked state, 
     FIG. 4 is a cross-section view of self-lock hub unit according to the first embodiment of the present application, which illustrates the tube legs are in an un-locked state, 
     FIG. 5 is a partial sectional, exploded perspective view of the self-lock hub unit according to the second embodiment of the present application, 
     FIG. 6 is a top plan view of the self-lock hub unit shown in FIG. 5, 
     FIG. 7 is a cross-section view of the self-lock hub unit shown in FIG. 5, which illustrates the tube legs are in a locked state, 
     FIG. 8 is a cross-section view of the self-lock hub unit shown in FIG. 5, which illustrates the tube legs are in an un-locked state, 
     FIG. 9 is a perspective view illustrating tube legs of the playyard are collapsed while the hub unit of the present application is in an un-locked state, 
     FIG. 10 is a perspective view illustrating tube legs of the playyard are erected while the hub unit of the present application is in a locked state, and 
     FIG. 11 is an exploded perspective view illustrating a prior art hub assembly of lower frame of a foldable playyard. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings to explain the present invention in detail. FIGS. 1-4 illustrated a self-lock hub unit according to the first embodiment of the present application. As shown in FIGS. 1 and 2, the self-lock hub unit  1  of a lower frame of a playyard generally comprises a body  10  having a plurality of slots  12  formed at a periphery thereof for receiving tube legs  60  of the playyard and a vertical cavity  14  formed at the center thereof; an actuating member  20  which is vertical movably received in the vertical cavity  14 ; two sliding engaging assemblies  30  movably mounted to two oppositely positioned tube legs  60  respectively at an open end of the tube legs and the two oppositely positioned tube legs  60  being rotatably received in two radially opposite slots  12  of the body respectively; and a strap  40  coupled to the actuating member  20 . 
     The tube legs  60  are pivotally coupled to the slots  12  of the body  10  through pins  61 . Each of the tube legs  60  has two opposite elongated openings  62  formed in a tube wall thereof at positions adjacent to the open end of the tube leg. Each of the sliding engaging assemblies  30  includes a spring  32  disposed in the tube leg  60  through the open end and abutting the pin  61 , a slide  34  disposed in the tube leg  60 , and a coupling pin  35  extending through the elongated openings  62  and the slide  34  to slidably couple the slide  34  to the tube leg  60  with both ends of the coupling pin  35  extending out over the tube wall a distance. The slide  34  will protrude out the open end of the tube leg  60  a distance because of the biasing fore exerted thereon by the spring  32 . The slide  34  is substantially a cylinder with an inwardly slanted surface  36  formed at the end extending out of the tube leg  60 . 
     The body  10  further comprises two locking assemblies formed at positions corresponding to the two oppositely positioned tube legs  60  respectively. Each of the two locking assemblies includes two locking member, i.e., locking members  16 ,  16 ′ and  17 ,  17 ′, wherein locking members  16 ,  17  are disposed at the top of two opposite side walls of the vertical cavity  14  and locking members  16 ′,  17 ′ are disposed at positions opposite to corresponding locking members  16 ,  17  with a space formed therebetween, as shown in FIG.  1 . The space between the locking members  16 ,  16 ′ and  17 ,  17 ′ is sized to be larger than an outer diameter of the tube leg  60  to allow the open end of the tube leg  60  and the portion of the slide  34  that protrudes out the tube leg can pass it while the tube leg  60  pivots about the pin  61 . Each of the locking members  16 ,  16 ′,  17 ,  17 ′ is of a reversed ‘L’ shape and has a vertical portion and a horizontal portion. The horizontal portion has a bottom face  19  (or  19 ′) and an outwardly inclined face  18  (or  18 ′) formed at a free end thereof. The locking members  16 ,  16 ′ and  17 ,  17 ′ are arranged at positions such that when tube leg  60  pivots about the pin and causes the open end of the tube legs  60  together with the portion of the slide  34  that protrudes out the tube leg to pass through the space between the locking members, the portions of the coupling pins  35  that extends out the tube wall will contact the inclined surfaces  18 ,  18 ′ of the locking members. 
     The actuating member  20  includes a head portion  21  and a stem portion  22 . The head portion  21  includes a left inclined face  23  and a right inclined face  24 . Both inclined faces  23 ,  24  are outwardly and downwardly slanted from the top of the head portion  21  to make the head portion  21  as an arrow shape. Stem portion  22  has an elongated longitudinal opening  25  formed therein. The actuating member  20  is movably received in the vertical cavity  14  of the body  10  and coupled to the body  10  by extending a rivet  26  through the opening  25  and fixing it to cavity walls. Optionally, the actuating member  20  may include a return spring (not shown) which is retained in the opening  25  by fixing one end thereof to the rivet  26  and abutting the other end to the bottom of the opening  25 . 
     While in use, tube legs  60  are lifted from a collapsed position (as shown in FIG. 9) and the open ends thereof will pivot about the pins  61  in a direction indicated by the arrows shown in FIG.  3 . As illustrated in FIGS. 3 and 4, when tube legs  60  pivot to a position where the portions of the coupling pin  35  extending out the tube wall contact the inclined surfaces  18 ,  18 ′ of the locking members, the coupling pin  35  will be pushed backward by the inclined surfaces  18 ,  18 ′ as the tube legs  60  continue to pivot upward until the tube legs  60  reach a horizontal position where the coupling pin  35  no longer contacts with the inclined surfaces  18 ,  18 ′. While the tube legs are pivoted to this horizontal position, the slide  34  together with the coupling pin  35  will be pushed forward by the spring  32  to a locked position where the portions of the coupling pin  35  extending out the tube wall engage with the bottom faces  19 ,  19 ′ of locking members (see FIG. 2) to thereby lock the tube legs  60  in an erected position, as shown in FIGS. 4 and 10. While at this locked position, at least one portion of the slide  34  extends into the cavity  14 . 
     When need to unlock tube legs, the strap  40  is pulled upwardly to cause the actuating member  20  to move upward and the inclined surfaces  23 ,  24  are caused to contact with the inwardly slanted surface  36  of the slide  34 . While the actuating member  20  continue moving upward, the slides  34  will be pushed further back into the tub legs  60  by the inclined surfaces  23 ,  24 . This backward movement of the slide  34  will cause the coupling pin  35  to move backward as well and the tube legs  60  will be unlocked when the coupling pin  35  moves a distance that is greater than the length of the bottom faces  19 ,  19 ′ of the locking members. While pulling the strap  40  further upward, the hub unit  1  and the entire lower frame of the playyard may be lift up by the actuating member  20  and the rivet  26 , and then the unlocked tube legs  60  will pivot to the collapsed position because of their own weights, as shown in FIG.  9 . 
     Referring now to FIGS. 5-8 to explain a hub unit  100  according to a second embodiment of the present invention. 
     The hub unit  100  according to the second embodiment of the present invention generally comprises a body  110  having a plurality of notches  112  formed at a periphery thereof for receiving tube legs  160  of the playyard; an actuating member  120  which is vertical movably coupled to the body  110 ; two sliding engaging assemblies  130  movably mounted to two oppositely positioned tube legs  160  respectively at an open end of the tube legs and the two opposite positioned tube legs  160  being rotatably received in two radially opposite notches  112  of the body respectively; and a strap  140  coupled to the actuating member  120 . 
     As shown in FIG. 5, the body  110  comprises a rectangular central recess  111  defined by two opposite long-side walls  1110 ,  1110 ′ and two short-side walls  1112 ,  1112 ′, wherein a notch  112  is formed at each of the short-side walls at a position corresponding to the oppositely positioned tube legs  160  for receiving an open end of the tub leg. The body  110  further comprises guiding plates  113 ,  113  disposed at the center portion of the recess  111  and arranged such that the guiding plates  113 ,  113  are spaced apart from each other so as to define a cavity  114  therebetween and are parallel with the short-side walls  1112 ,  1112 ′. Each of the guiding plates  113 ,  113  comprises a horizontal portion  115 ,  115 ′ protruding outwardly from a top portion of sides at width direction. The horizontal portions  115 ,  115 ′ are parallel with and spaced apart from the long-side wall  1110 ,  1110 ′ of the recess  111 , i.e., a space  116 ,  116 ′ is defined between the horizontal portions  115 ,  115 ′ and the long-side wall  1110 ,  1110 ′ of the recess  111 . The horizontal portions  115 ,  115 ′ has a lower edge  119 ,  119 ′ and an outwardly slanted face  117 ,  117 ′ formed at a free end thereof. 
     The tube legs  160  are pivotally coupled to the notches  112  of the body through pins  161 . Each of the tube legs  160  has two opposite elongated openings  162  formed in a tube wall thereof at a position adjacent to the open end of the tube leg. Each of the sliding engaging assemblies  130  includes a spring  132  disposed in the tube leg  160  through the open end and abutting the pin  161 , a slide  134  disposed in the tube leg  160 , and a coupling pin  135  extending through the elongated openings  162  and the slide  134  to slidably couple the slide  134  to the tube leg  160  with both ends of the coupling pin  35  extending out the tube wall a distance. 
     The actuating member  120  comprises an elongated stem portion  122  and two actuating plate  123 ,  123 ′ transversally formed at a top of the stem portion  122 . The stem portion  122  is sized and shaped so that it can be movably received in the cavity  114 . Stem portion  122  has an elongated longitudinal opening  124  formed therein. The actuating member  120  is movably coupled to the body  110  by extending a rivet  125  through the opening  124  and fixing it to cavity walls. Actuating plate  123 ,  123 ′ are formed at sides of the stem portion  122  facing the long-side walls  1110 ,  1110 ′ respectively and arranged such that when the actuating member  120  is received in the cavity the actuating plates  123 ,  123 ′ will be received in the space  116 ,  116 ′. An outwardly slanted face  126 ,  126 ′ is formed at free ends of each of the actuating plates  123 ,  123 ′. The actuating member  120  further includes a return spring  127 , which is retained in the opening  124  by fixing one end thereof to the rivet  125  and abutting the other end to the bottom of the opening  124 . 
     While in use, tube legs  160  are lifted from a collapsed position (as shown in FIG. 9) and the open ends thereof will pivot about the pins  161  in a direction indicated by the arrows shown in FIG.  7 . When tube legs  160  pivot to a position where the portions of the coupling pin  135  extending out the tube wall contact the inclined surfaces  117 ,  117 ′ of the horizontal portion  115 ,  115 ′ the coupling pin  35  will be pushed backward by the inclined surfaces  117 ,  117 ′ as the tube legs  160  continue to pivot upward until the tube legs  160  reach a horizontal position where the coupling pin  135  no longer contacts with the inclined surfaces  117 ,  117 ′. While the tube legs  160  are pivoted to this horizontal position, the slide  134  together with the coupling pin  35  will be pushed forward by the spring  132  to a locked position where the portions of the coupling pin  135  extending out the tube wall engage with the lower edge  119 ,  119 ′ of horizontal portion  115 ,  115 ′ (see FIG. 7) to thereby lock the tube legs  160  in a erected position, as shown in FIGS. 7 and 10. While at this position, the actuating member  120  is retained at the bottom of the cavity  114  because of the spring force exerted by the return spring  127 . 
     When need to unlock tube legs, the actuating member  120  is caused to move upward by upwardly pulling the strap  140  and the outwardly slanted faces  126 ,  126 ′ of the actuating plates  123 ,  123 ′ are caused to contact with the portions of the coupling pin  135  extending out the tube wall. While the actuating member  120  continues to move upward, the portions of the coupling pin  135  engaging with the lower edge  119 ,  119 ′ of horizontal portion  115 ,  115 ′ will be pushed further back into the tub legs  160  by the outwardly slanted faces  126 ,  126 ′. This backward movement of the coupling pin  135  will cause the tube legs  160  to be unlocked when the coupling pin  135  moves a distance that is greater than the length of the lower edge  119 ,  119 ′ of horizontal portion  115 ,  115 ′. While pulling the strap  140  further upward, the hub unit  100  and the entire lower frame of the playyard may be lift up by the actuating member  120  and the rivet  125 , and then the unlocked tube legs  160  will pivot to the collapsed position as shown in FIG.  9 . 
     This invention has been disclosed in terms of specific embodiments. It will be apparent for people skilled in this art that many modifications can be made to the disclosed structures without departing from the invention. Therefore, it is the intent of the appended claims to cover all such variations and modifications as come within the true spirit and scope of this invention.