Abstract:
An improved scaffold connection is provided, attachable to a vertical scaffold member having a plurality of ring members. The scaffold joint has an upper side and a lower side, and an upper hook section and a lower hook section engagable with the ring members on the vertical scaffold members. The invention includes two latches to lock the joint to two ring members, where the two latches are mechanically connected.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to connections for scaffolding and, more particularly, to latchable scaffolding connections between horizontal and vertical scaffold members. 
     2. Background of the Invention 
     Many different designs have been employed to secure the ends of horizontal scaffold members to vertical scaffold members. Because of a concern for a positive locking arrangement, prior art connections employ a latch assembly, whereby the connection between a horizontal and a vertical member is held in place against an uplifting force by some type of latch. One such joint is disclosed in U.S. Pat. No. 4,445,307, which discloses a connector positioned on a horizontal scaffold member, where the connector has two vertically spaced hook sections. These hook sections couple with two vertically spaced upstanding ring members located on the vertical scaffold member. To withstand an uplifting force, the connector includes a wedge that is driven (generally by a hammer) into position below the upper ring member, thereby latching the connector hook sections against the ring member through a wedging type of action. 
     A second type of latching connector is disclosed in U.S. Pat. Nos. 5,078,532 and 5,028,164, hereby incorporated by reference. These patents also show a connector positioned on a horizontal scaffold member, where the connector has two vertically spaced hooked sections that couple with two vertically spaced upstanding ring members located on the vertical scaffold member. In this device, the latching of the ring members to the hooked sections is accomplished by a deploying a pivoting member, positioned on the connector, into position below the top ring member. The pivoting member cages or traps the connector to the vertical member, thereby resisting an uplifting force. The pivoting member allows for ease of assembly of a scaffold structure, and the assembled joint retains a degree of play, as this connector lacks the wedging action of the &#39;307 patented device. 
     By using a two points of attachment between a horizontal and vertical member (the two hooked sections coupled to the two upstanding ring members), the &#39;532 join and the &#39;307 join are more resistive to torsional forces than would be a single ring/hook section embodiment, such as shown in U.S. Pat. No. 4,369,859. However, because the bottom hook of the &#39;532 connector and &#39;307 connector is not latched to the bottom ring member, the connector is still weak when subject to high torsional forces; for instance, it is not recommended that a worker tie onto a horizontal member that is designed only as specified in the &#39;532 patent, as a falling worker will subject that connector to high torsional force and possible connector failure. Hence it is desired to have a scaffold join that is more resistive to torsional forces, that enables a scaffold structure to be easily and quickly erected, and can be used with existing vertical scaffold members. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of this invention to provide an improved scaffold latch mechanism that latches at two vertically offset points, and which can be quickly and efficiently installed or dismantled without the aid of tools. 
     Accordingly, an improved scaffold connector is provided that has an upper side and a lower side, and an upper hook section and a lower hook section engagable with the ring members on a vertical scaffold members. The invention includes two latches to lock the connector to two ring members, where the two latches are mechanically coupled. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a side view of scaffold joint shown attached to a vertical scaffold member in a latched configuration, where the leg portion is shown cutaway. 
         FIG. 1B  is a side cross sectional view of one embodiment of the scaffold connector in an unlatched configuration invention. 
         FIG. 2  is side view cross sectional view of another embodiment of the scaffold connector in an latched configuration. 
     
    
    
     DETAILED DESCRIPTION 
     Shown in  FIG. 1A  is a scaffold connector  1 , joining a vertical scaffold member  10  with a horizontal scaffold member  20 . Positioned on the vertical scaffold member  10  is a plurality of ring members  11 . In general, the vertical scaffold member  10  will have a series of ring members  11  positioned at regular intervals along the length of the vertical member. Ring members  11  are positioned in a vertically spaced apart relationship on the vertical scaffold member  10 . Shown in  FIG. 1A  are upper ring member  12 , and lower ring member  13 . Ring members have an upper side  14  and a lower side  15 . As shown, ring members  11  are upwardly curved cup shaped members. Alternative ring members can be seen in U.S. Pat. Nos. 4,044,523 and 4,039,264 hereby incorporated by reverence 
     The connector  1  is fixedly attached to the horizontal scaffold member  20 , preferably by welding. As shown, connector  1  has a connector body with a top housing  2  shaped to accept a horizontal scaffold member  20 . Protruding from the top front edged of the connector body is upper hook section  3 . Downwardly projection from the housing  2  is leg portion  6 . Leg portion has two opposing sides, a front edge  7  and a rear edge  8 , and terminates in lower hook section  4 . As shown, hook portion has a front lip and a rear lip formed by the leg portion, forming a “U” shaped channel between the two lips. A single lip or tooth can be used (e.g. terminate the back lip section of the leg portion before the hook section) but this is not preferred as the double lip results in a more stable attachment. A cavity is formed between the two opposing sides. The opposing sides of the leg portion  6  on the rear edge  8  are folded inwardly and joined at two locations  9 A and  9 B (generally by welding) on the read edge  7 . These joins provide strength and provide support for latch members and resilient bias means. Upper  3  and lower  4  hook sections are adapted to engage with the ring members, as shown, upper side  14  portion of upper ring member  12  and lower ring member  13  engage hook portions. At the lower hook section  4 , the leg portion&#39;s sides are flared outwardly (shown as region  9 C) providing for added stability when the lower hook section  4  is engaged with a ring member. 
     Within the cavity between the opposing sides are two latch members, upper latch member  30  and lower latch member  40 . Latch members are secured within the cavity by pins  31 A and  31 B, and pivot on these pins. Upper latch member is “Y” shaped with the leg  33  of the “Y” functioning as a handle, the upper leg of the “Y” containing the latch surface  34 , and the lower leg  35  mechanically coupled with the lower latch member  40 . The lower latch member is L” shaped with the bottom of the “L containing the latch surface  44 , and the upper leg of the “L mechanically coupled to the upper latch member  30 . As shown, the two latch members are coupled by a pin  46  on one latch (as shown, the lower latch) engaging a slot  36  on the other latch (as shown. the upper latch). Through this mechanical coupling, joint movement of the two latch members can be effectuated through manipulation of the handle  33  alone. The dual latch mechanism is biased into a “latched” or closed configuration by a resilient biasing means, here a spring  50  position above and operating on upper latch  30 . 
     Operation of the Latch 
     As shown in  FIG. 1A , in a closed or latched configuration, latch surface  34  of upper latch member  30  is positioned in a first position, below the upper hook section  3  and below the lower surface  15  of the upper ring member  30 ; lower latch member  40  latch surface  44  is positioned in a first position, beneath lower hook section  4  and under lower surface  15  of lower ring member  13 , thereby securing the horizontal scaffold member  20  to the vertical scaffold member  10  and resisting upward movement of the horizontal scaffold member. To “unlatch” the connector, the operator depresses or pivots the handle  33  of upper latch member  30  downwardly, thereby compressing spring  50 . In response to this action, upper latch member  30  rotates about pin  31 A and the upper latch surface  34  rotates to a second position away from upper ring member  12 , thus unlatching the upper latch member  30 . Since the upper latch member  30  is mechanically coupled to lower latch  40 , the rotation of the upper latch member  30  results in the rotation of the lower latch member  40  about its supporting pin  31 B (as constructed, the lower latch member  40  rotates in the opposite direction from that of the upper latch member  30 ). Rotation of the lower latch member  40  moves the lower latch surface  44  away from the lower ring member  13 , thus unlatching the lower latch member  40 . In the unlatched configuration, shown in  FIG. 1B , the horizontal scaffold member can be uplifted and removed from the vertical scaffold member. 
     To attach the connector  1  to a vertical scaffold member  10 , the operator can depress the handle  30  to rotate the two latches away from the locked or latched position, (the connector  1  is in a “normally latched” configuration by operation of the spring  50 ); however, in general, this is not necessary. The operator can simply place the hook sections  3  and  4  of the connector on the respective ring members and press down. The action of pressing down will move the latch surfaces  34  and  44  away from the latched position and compress the resilient biasing member  50 . When the hook sections  3  and  4  are engaged to the ring members, the latch members  30  and  40  will spring back into the latched position by operation of the resilient biasing means  50 . That is, the connector can be “snapped” into place on a vertical scaffold member, making for ease and rapidity in assembly of a scaffold structure. 
     As shown, the dual latches are mechanically coupled by a pin and slot configuration. The two latch members may be mechanically coupled simply by a suitable overlap of the latch members, such as shown in  FIG. 2 . However, this arrangement is not preferred, as a second resilient biasing means  51  is needed in this configuration to bias the lower latch member  40  into an open position. Other embodiments are feasible for the design shown in  FIG. 1A , such as placing the handle  33  on the lower latch member, and lifting up the handle to operate the mechanism; locating the spring or resilient biasing means in the leg portion to bias either the lower latch or upper latch member into a closed or latched configuration. Alternatively, the leg portion  6  can be extended further downward to allow the lower latch member  40  to be pivotally connected to the leg portion  6  below the lower hook section  4 , so that the lower latch member  40  would rotate in the same direction as the upper latch member  30 . In this embodiment, both lower and upper latch members can have handles, and the two latch members may be mechanically coupled by using a bar pivotally joined to both handles, such as through the pin/slot arrangement discussed above or other means. 
     Instead of a leg composed of two opposing sides with a cavity between, the leg portion  6  may be a single plate with the latches  30  and  40  pivotally pinned to the leg portion  6 . However, this arrangement is not preferred, as the latches are exposed and can be more readily damaged. Other embodiments of the invention will occur to those skilled in the art, and are intended to be included within the scope and spirit of the following claims. 
     As can be seen, an improved scaffold connection is provided which more securely locks a horizontal scaffold member to a vertical scaffold member. The improved connection is versatile in its application, and allows for continued use of existing vertical scaffold members equipped with ring members.