This invention relates to a support post for use with a fence assembly at a construction site. In particular, the invention relates to a locking and lifting mechanism for securing telescoping inner and outer tubes comprising a support post.
Safety barriers or fences are used during the construction of high-rise buildings to prevent construction workers from falling from the building and injuring themselves. They are also useful to prevent materials from falling from the building and for catching any flying debris being blown against the barriers and injuring people below. The safety barriers need to be set up and taken down with relative ease since they are temporary and frequently moved from one location to another as the construction progresses. A safety barrier of this type typically comprises a plurality of posts supporting intervening fence panels.
Various types of support posts and fencing assemblies have been designed to try and address this need for a safety barrier. U.S. Pat. No. 3,822,850 discloses a support for a construction fence. The support comprises a telescoping jack post which can be adjusted to fit snuggly between a floor and ceiling. U.S. Pat. No. 3,589,682 discloses another type of telescopic fence column which has a manually operable jacking system and upper and lower pads for contacting the ceiling and floor of a portion of the building. U.S. Pat. No. 3,946,992 discloses another type of construction fence post which comprises a C-shaped bracket which is used to clamp the post to the edge of the floor section. U.S. Pat. No. 3,734,467 describes an upright for a wall partition which has a compression spring that allows for frictional engagement of the upright between floors of a building under construction. U.S. Pat. No. 6,679,482 discloses an improved construction perimeter guide stanchion. An adjustment system allows one to tightly clamp the pair of jaws at the lower end of the stanchion to the edge of a floor slab in an elevated unfinished building.
Although many attempts have been made to design improved safety barrier systems, there remains a need for a system that is easily erected and dismantled and which is self-adjusting, easily packaged safer and tamper-proof. In Applicant's co-pending U.S. patent application Ser. No. 10/901,141, there is provided a support post and safety fence assembly in which the post has a telescoping inner and outer tube and is supported on a threaded internal shaft coupled to a floor engaging end. A ceiling engaging end is preferably formed with claws that have a number of sharp penetrating points for firm engagement with a support surface. Dynamic adjustability of the support post is provided by internal compression springs which also allow the post to be temporarily positioned in an upright position prior to securement.
In accordance with this invention, there is provided a support post having an over-centre locking lever assembly for fixing the relative position of telescoping inner and outer tubes in a support post for a safety fence assembly. The locking lever assembly includes a collar slideable longitudinally over the telescoping inner tube and a lever pivotally mounted to the collar on a pivot pin and pivotable between a release position where the collar is freely movable on the telescoping inner tube and a lock position where the lever has moved past a center line and the collar is tilted to grip the telescoping inner tube. Preferably, the lever is bifurcated at an inner end into a pair of cam portions that receive the pivot pin therebetween. The cam portions will bear against an upper pheripheral edge of the telescoping outer tube and have a curvature and shape adapted to raise the pivot pin so that the collar is raised above the upper peripheral edge of the telescoping outer tube and tilted to grip an outer surface of the telescoping inner tube.
a is an assembly view of a post made in accordance with the invention;
b is a cross-sectional view showing a top end of the post of
c is a perspective view showing the top end of the post of
d is a perspective view showing a bottom end of the post of
The invention provides a safety fence assembly generally indicated by reference numeral 20 and consisting of a plurality of upright support posts 22 that extend between a supporting surface or floor 24 and a ceiling 26. The posts are normally positioned adjacent to an opening and spaced apart by a distance commensurate with the length of an associated fence panel or barrier 28. The fence panel 28 is normally positioned on the interior side of the associated support post 22 and thus in the view of
The construction of the support post 22 is shown in more detail in
As will be observed in the detail view of
As will observed from
The floor engaging end 30 is rotatably coupled to a reduced diameter portion of a shaft 42 which extends upwardly in the operative orientation of the support post 22. The shaft 42 is a solid steel bar that has a free end 44 approximately six inches in length that is threaded along its length and concealed from view inside the outer tube 36. The outer tube 36 has an internal nut 46 welded to its interior surface adjacent a lower end thereof and having complementary threads to the threaded end 44 of the shaft 42. The lower extremity of the outer tube 36 has a guide bushing 48 for sliding engagement with the shaft 42 and which closes the lower end of the outer tube 36 to prevent the ingress of dirt into the assembly. A plate 50 (as drawn) or pin is welded to the interior surface of the outer tube 36 above the height of the threaded end 44 of the shaft 42 to stop the telescoping inner tube from falling onto the shaft 42.
The ceiling engaging end 32 is rotatably coupled to a stem 52 which is slidingly received in the operatively upper end of the inner tube 34. The stem 52 carries a longitudinally extending pin 54 which has a head that locates against a collar 56 welded to the interior surface of the inner tube 34. A top compression spring 58 is captured between the supporting collar 56 and the stem 52. Thus, the application of pressure to the ceiling engaging end 32 will cause the stem 52 to penetrate into the inner tube 34 and compress the compression spring 58 as illustrated by
In accordance with this invention, an over-centre locking lever assembly 60 is provided for fixing the relative position of the telescoping inner tube 34 and outer tube 36. The locking lever assembly 60 is illustrated in
The over-centre locking lever assembly 60 consists of a collar 62 having a square cross-section which is somewhat larger than the cross-section of the inner tube 34 so that the collar 62 can slide longitudinally along the length of the inner tube 34. A downwardly extending lip 64 (as drawn) on one side of the collar 62 is disposed to rest on an upper peripheral edge of the telescoping outer tube 36. The opposite side of the collar 62 has a pivotally mounted lever 66 or handle which is bifurcated at its inner end into a pair of cam portions 68 that receive a pivot pin 70 therebetween. The pivot pin 70 is fixed to opposite sides of the collar 62 and defines a pivot axis 72 (
To operate the over-centre locking lever assembly 60, the telescoping inner tube 34 and telescoping outer tube 36 are separated from their rest position shown in
In order to ensure that the lever 66 remains centered on the post 22 with the cam portions 68 engaging the upper peripheral edge of the telescoping outer tube 36, the telescoping outer tube 36 is made with somewhat thicker walls in the portions which engage the cam portions 68. The telescoping outer tube 36 also has oppositely disposed receiving grooves 90 formed in a thickened wall portion 91 (
In an alternative embodiment of the invention, the cam portions 68 are replaced by straight edges and by a pivot bar that bears against the telescoping outer tube 36 as described with reference to
When the lever 66 is brought to rest against the telescoping outer tube 36 in its lock configuration shown by the solid line of
An opening 102 is formed in the lever 66 adjacent the cam portions 68 to receive and locate the thickened wall portion 91 of the telescoping outer tube 36.
Relative slipping between the telescoping inner and outer tubes 34, 36 is limited by engagement of the spring clip 80 against the telescoping inner tube 34, the thickened wall portion 91 of the outer tube 36 being received in the opening 102 of the lever 66 and by an inner leaf spring 104 shown in
After release of the lever 66, the telescoping inner tube 34 drops a small amount sufficient to shorten the post 22 to a height which clears the separation between the ceiling 26 and the floor 24. The collar 62 is released from its tilted locking configuration by twisting the lever 66 or by hitting the collar 62 with a hammer.
During transportation of the post 22, the telescoping inner and outer tubes 34, 36 are maintained in position by engagement of the spring clip 80 in the receiving opening 82 formed in the telescoping outer tube 36 and by the continued frictional engagement of leaf spring 104 against the interior surface of telescoping outer tube 36.
It will be appreciated that fine adjustments up to an additional six inches may be made to extend the length of the post 22 and maintain optimum pressure on the ceiling engaging end 32.
To secure final placement of the support post 22, the outer tube 36 together with the inner tube 34 may be rotated on the threaded shaft 42. The thread of the threaded end 44 and the nut 46 are formed so that a counterclockwise rotation will bring about an upward vertical movement of the inner and outer tube assembly 34, 36. As pressure is applied to the ceiling engaging end 32, the inner tube 34 moves upwardly relative to the stem 52 thereby obscuring the stem from view. Conveniently the stem 52 may have a bright color applied to it such as a red colored band to provide a visual indication of the load being applied to the top compression spring 58. As observed in
An alternative embodiment of the over-centre locking lever assembly will now be described with reference to
Accordingly, the post assembly has a telescoping inner tube 34 and a telescoping outer tube 36 with a U-shaped collar 62 that can slide longitudinally along the length of the telescoping inner tube 34. An internal surface of the collar 62 has serrations 88 for gripping engagement with the telescoping inner tube and a pivotally mounted lever 66 or handle is coupled to the collar 62 opposite from the serrations 88 at a first pivot pin 70. The handle 66 is bifurcated at its inner end to receive the pivot pin 70 between legs 66a, 66b. A housing 122 covers the pivot pin 70 to keep the pin 70 clean and to act as a bearing surface for a coil spring 124 as will be described.
A pivot bar 126 is pivotally mounted between legs 66a, 66b on a second pivot pin 128 extending therebetween and positioned between the first pivot pin 70 and the lever body 66. The pivot bar 126 is adapted to swing on the second pivot pin 128 to engage the upper peripheral surface of telescoping outer tube 36 with its free end as shown in
Most preferably, the pivot bar 126 is itself bifurcated at the pivot end that receives pivot pin 128 and receives spring coil 124 therebetween with free ends of the spring coil 124 bearing on the housing 122 and on the pivot bar 126 to thereby urge the pivot bar 126 into engagement with the telescoping inner tube 34.
The operation of the over-centre locking lever assembly 120 is similar to the assembly 60 previously described. As seen in
When the lever 66 is brought to rest against the telescoping outer tube 36 in its lock configuration shown in
Once positioned, the support post 22 is extremely stable and secure so that it can successfully withstand pull or push tension tests applied to its mid portion thereby complying with regulations of the applicable health and safety legislation or other legislation.
In use, the support post 22 is erected at selected locations and a plurality are positioned at suitable distances required to support fence panels positioned in overlapping fashion as shown in
As will be appreciated by those skilled in the art, several variations may be made to above-described embodiment of the invention within the scope of the appended claims.
Number | Date | Country | Kind |
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2,515,750 | Aug 2005 | CA | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CA2006/001309 | 8/9/2006 | WO | 00 | 8/12/2010 |