Background of the Invention
1. Field of the Invention
This invention pertains to safety equipment, and more particularly to fences.
2. Description of the Prior Art
Various types of railings and similar barriers have been developed to protect spectators from falling from bleachers and stands. With fixed stands, which are usually installed out of doors, it is a common practice to erect permanent guard railings around the ends and top of the stands, and also around stairwells. However, collapsible indoor bleachers present a more difficult problem. Permanent guard rails are not practical along the ends of the bleachers, as such guard rails would interfere with opening and closing the bleachers.
It is possible to adapt various assemblable and disassemblable structures such as scaffolds and the like for use as bleacher guard rails. For example, U.S. Pat. Nos. 4,140,414; 4,142,809; and 4,537,540 show various types of frames that are assemblable by means of headed connection members and cooperating slots. Other scaffold related connectors may be seen in U.S. Pat. Nos. 2,435,171; 2,588,905; 4,165,944; and 4,718,787. U.S. Pat. No. 4,413,366 shows a bed frame that includes locking pins and hooks for removably assembling side rails to the headboard and footboard.
Despite the wide variety of prior rail-like structural members and connections, for various reasons none is entirely suitable for use as a bleacher guard. One important reason is that the prior structures do not include grill-like components specifically intended to prevent persons from passing through them.
Thus, a need exists for practical bleacher guards.
Summary of the Invention
In accordance with the present invention, a versatile guard fence system is provided that is specifically designed for use with portable bleachers. This is accomplished by apparatus that includes a guard fence member that is quickly and easily assembled to and that spans an entire area between two spaced support posts.
The support posts may be permanently mounted to the bleachers at any desired location such as on the ends of a section or along the back on the top section. Each post has two U-channels attached to it. A lower U-channel has a relatively deep open-top vertically oriented slot. An upper U-channel is spaced at a predetermined distance above the lower U-channel. The upper U-channel has a relatively short open-top vertically oriented slot. The upper U-channel has a hole through it parallel to the plane of the slot and above the bottom surface of the slot.
The guard fence member has a generally rectangular frame with a grill of woven wire or similar fence-like material covering the frame opening. The width of the frame is slightly less than the spacing between two support posts when the bleachers are in their installed position. Two pins extend laterally from each side of the frame. The two pins on each side of the frame are spaced apart a distance equal to the spacing between the slots in the lower and upper U-channels on the posts.
To use the guard fence system of the present invention, support posts are mounted at desired locations on the bleachers. A guard fence member is held in any non-vertical attitude between two posts. The pins at the lower end of the guard fence member frame are placed within the corresponding slots in the lower U-channels of the two posts. Then the guard fence member is rotated upwardly about the pivot point formed by the frame lower pins and the lower U-channels on the posts. When the guard fence member is almost vertical, the two upper pins thereon are proximate the corresponding two upper U-channels on the posts. The guard fence member is lifted a short distance until the upper pins thereon clear the top ends of the upper U-channel and can be aligned vertically over the slots in the two upper U-channels. The slots in the lower U-channels of the two posts are long enough so that the frame lower pins do not rise out of the lower U-channels when the guard fence member is lifted. Then the guard fence member is lowered such that the upper pins thereon enter the upper U-channel slots, and the guard fence member is sturdily in place on the post. To eliminate the possibility of unintentional disassembly of the guard fence member from the post, bolts are inserted through the holes in the upper U-channels above the associated pins. The bolts must be removed before the guard fence member can be lifted out of the U-channels.
As many guard fence members as desired can be installed along the bleachers to form a continuous fence-like guard. The ends posts of a series may have a single lower U-channel and upper U-channel. The posts intermediate the end posts have two sets of lower and upper U-channels that extend from opposite sides of the post. In that manner, one intermediate post supports the sides of two different guard fence members.
Other advantages, benefits, and features of the invention will become apparent to those skilled in the art upon reading the detailed description of the invention.
Brief Description of the Drawing
FIG. 1 is a front view of a typical portion of the guard fence system of the present invention.
FIG. 2 is an enlarged cross-sectional view taken along lines 2--2 of FIG. 1.
FIG. 3 is a cross-sectional view taken along lines 3--3 of FIG. 2 and rotated 90.degree. clockwise.
FIG. 4 is an enlarged cross-sectional view taken along line 4--4 of FIG. 1.
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 4 and rotated 90.degree. clockwise.
FIG. 6 is a view taken along line 6--6 of FIG. 1.
Detailed Description of the Invention
Referring to FIGS. 1-6, a guard fence system 1 is illustrated that includes the present invention. The guard fence system is particularly useful for preventing persons from falling from stands and bleachers, but it will be understood that the invention is not limited to applications involving elevated structures.
The guard fence system comprises a number of posts typically represented at reference numerals 3, 5, and 7. The guard fence system is very versatile, and the posts are designed to suit the specific application. The lower end of each post is mounted to the desired structural member, such as the end of a bleacher section, not shown. The particular structural member dictates the mounting design incorporated into the post. For example, the post may be straight for its entire length and have a single flat plate welded to the post lower end, such as is shown at post 3 and plate 9 of FIG. 1. Some applications may require a more elaborate mounting design, such as a curved post with several plates fixed to one or more short side bars. FIGS. 1 and 6 illustrate a representative design of a post 5 having two plates and side bar combinations 11. In all cases, the mounting of the posts 3, 5, and 7 to the bleachers or other structural members is intended to be permanent.
The guard fence system 1 further comprises a number of guard fence members 13 that, unlike the posts 3, 5, 7, are intended to be assembled to the posts on a temporary basis. Consequently, the guard fence members 13 are designed for quick and easy assembly to and disassembly from the posts. The guard fence members are identical in their basic construction, although they may vary in size to suit the specific application at hand.
Any number of posts and guard fence members 13 may be assembled into a single guard fence system 1. Each guard fence member of a system is assembled between two posts. For that purpose, each post has a lower U-channel 15 and an upper U-channel 17 welded or otherwise attached to the post. Looking especially at FIGS. 2 and 3, each lower U-channel 15 has a generally channel-shaped cross-section composed of a middle leg 23 and two side legs 21. The lower U-channel is preferably approximately 3.5 inches in overall length. The free ends of the channel side legs 21 are welded to the post. The middle leg 23 is formed with a vertically extending slot 25 that is open at the top end 27 of the U-channel. The slot 25 preferably extends for approximately 2.75 inches from the U-channel top end 27 and terminates in an arcuate bottom surface 28.
The upper U-channels 17, FIGS. 4 and 5, are also fabricated as channel members having end legs 29 and 30 and a middle leg 31. The overall length of the upper U-channel is preferably approximately 2.75 inches. The free ends of the end legs 29 and 30 are welded to the post. The end leg 30 is approximately one inch shorter than the end leg 29 so that the top end 35 of the U-channel has a step 36. The upper U-channel has a slot 33 that opens from the top end 35 and the step 36. The depth of the slot 33 may be approximately 2 inches from the top end 35. A pair of concentric holes 37 and 39 are formed in the upper U-channel side legs 29 and 30, respectively, at a location between the upper U-channel step 36 and the bottom 38 of the slot 33. The hole 37 may be round, but I prefer that the hole 39 is square to accept the square portion 41 of the head of a carriage bolt 43.
Each guard fence member 13 is manufactured with a rectangular frame 45 of bar channels or similar structural components. The area between the frame 45 is filled with a grill 47, such as woven wire or chain links. Extending outwardly from each vertical structural component 49 of the frame near its lower end is a headed pin 19. Similar pins 20 extend outwardly from the upper ends of the respective vertical components 49. The vertical spacing between the pins 19 and 20 of each vertical component is substantially equal to the spacing between the bottom surfaces 28 and 38 of the slots 25 and 33 of the post lower U-channel and upper U-channel 15 and 17, respectively.
To assemble a guard fence member 13 between two posts, such as between posts 3 and 5, the guard fence member is held in any non-vertical attitude on the same side of the posts as the short legs 30 and steps 36 of the upper U-channel 17. The pins 19 at the lower end of the guard fence member are inserted into the slots 25 of the corresponding lower U-channels 15 until the pins rest on the slot bottom surfaces 28. Then the guard fence member is pivoted toward the vertical until the pins 20 at the upper end of the guard fence member are proximate the corresponding upper U-channel 17 on the posts. The guard fence member is lifted approximately 1.25 inches, which raised the pins 20 above the upper U-channel steps 36. The guard fence member can then be pivoted to the vertical orientation such that the pins 20 are vertically over the slots 33. The relatively long lengths of the lower U-channels 15 assure that the pins 19 remain in the lower U-channel slots 25 when the guard fence member is lifted. When the pins 20 are vertically over the slots 33 of the upper U-channel member, the guard fence member is lowered until both pins 19 rest on the bottom surfaces 28 of the respective lower U-channel slots 25 and the pins 20 simultaneously rest on the bottom surfaces 38 of the upper U-channel slots 33. A carriage bolt 43 is inserted through the holes 37 and 39 of each upper U-channel and is retained there with a nut 51. The guard fence system 1 is then securely in place, providing protection against a person falling from the bleacher area adjacent the system.
As mentioned, the guard fence system 1 is exceptionally versatile. A single guard fence member 13 may be used in conjunction with two posts, such as posts 3, each having a single lower U-channel 15 and upper U-channel 17. On the other hand, a guard fence system can contain several guard fence members and the corresponding posts. It is contemplated that a post with a single lower U-channel and upper U-channel, such as post 3, will be used at both ends of an installation, and the posts with double lower and upper U-channels will be used intermediate the end posts.
Thus, it is apparent that there has been provided, in accordance with the invention, a guard fence system that fully satisfies the aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.