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 '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 '532 join and the '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 '532 connector and '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 '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.
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.
Shown in
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 9A and 9B (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's sides are flared outwardly (shown as region 9C) 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 31A and 31B, 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
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
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.
Number | Name | Date | Kind |
---|---|---|---|
835280 | Haskell | Nov 1906 | A |
1573866 | Rogers | Feb 1926 | A |
3179212 | Gostling | Apr 1965 | A |
3195735 | Jay | Jul 1965 | A |
3268252 | Rolland | Aug 1966 | A |
3476425 | Chartrand | Nov 1969 | A |
3482873 | Pivacek | Dec 1969 | A |
3490189 | Gostling | Jan 1970 | A |
3817641 | Steele et al. | Jun 1974 | A |
3879143 | Gostling | Apr 1975 | A |
3880533 | Gostling | Apr 1975 | A |
3992118 | Siegers | Nov 1976 | A |
4039264 | Sharp | Aug 1977 | A |
4044523 | Layher | Aug 1977 | A |
4090798 | Barton | May 1978 | A |
4180342 | Layher | Dec 1979 | A |
4273463 | Dobersch | Jun 1981 | A |
4369859 | Smits | Jan 1983 | A |
4445307 | Puccinelli et al. | May 1984 | A |
4586842 | Puccinelli | May 1986 | A |
5078532 | Williams | Jan 1992 | A |
5620212 | Bourne et al. | Apr 1997 | A |
Number | Date | Country |
---|---|---|
2352194 | Dec 1977 | FR |
1163533 | Sep 1969 | GB |
1310529 | Mar 1973 | GB |
7801928 | Aug 1979 | NL |