US3444793A - Manhole guardrail - Google Patents

Description

y 1969 T. A. PELSUE 3,444,793

MANHOLE GUARDRAIL Filed May 4, 1967 'INVENTOR.

THURMAN A. PELSUE FIG. 2.

May 20, 1969 Filed May 4, 1967 T. A. PELSUE 3,444,793

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8 THURMAN A. PELSUE United States Patent 3,444,793 MANHOLE GUARDRAIL Thurman A. Pelsue, 3706 S. Hibiscus Way, Denver, Colo. 80237 Filed May 4, 1967, Ser. No. 636,040 Int. Cl. E02d 29/14 U.S. Cl. 9438 Claims ABSTRACT OF THE DISCLOSURE This invention consists of an upstanding foldable tubular guardrail made in three sections, the end sections of which are provided with arcuate brackets adapted to engage the outside cylindrical surface of a manhole shield of the type shown in U.S. Patent No. 3,294,000 while being held in contact therewith by means of a detachable elastic member stretched between said end sections.

The inventor of the instant invention is also the inventor of the above-identified patented manhole shield which fits down into and forms a watertight seal with the ring bordering a manhole. A considerable portion of the shield projects upwardly above ground level and serves the valuable function of providing a standpipe capable of preventing ground water produced by rain, melting snow, irrigation and the like from entering the manhole to the considerable discomfort of the workmen engaged therein, to say nothing of the possible damage it might do to the subsurface installations. Thus, manhole shields made in accordance with the above patent, along with certain other designs that serve the same general purpose, are becoming more and more widely used by the public utilities service people.

While, to some extent, the above-described manhole shields serve the secondary function of guarding the entrance to the manhole so that pedestrians and vehicles do not accidently enter same when uncovered, additional protection in the form of a waist-high guardrail is generally considered a necessity. Such guardrails are in common use and have been available for many years in one form or another. In all cases, however, the prior art guardrails for manholes comprise nothing more than free-standing fences formed of pipe or some other tubular material and none of them, to applicants knowledge, connect in any way to the ring surrounding the manhole or any other accessory used therewith. For this reason, the guardrail can easily be moved aside by a person walking against it and, as such, the unit fails to provide the measure of protection for which it was designed.

The problem of providing a guardrail with the requisite stability to remain in place in a free-standing position also requires that it be constructed of relatively thickwalled heavy tubing. The weight of the unit thus becomes excessive and it becomes difficult to load and unload from a service truck as well as set up in the street around an open manhole, especially when it is considered that the user must either stand outside thereof or straddle the manhole opening when doing so.

Uneven terrain in the area immediately surrounding the manhole also makes it diflicult to use a free-standing guardrail. Even in city streets and alleys, the built-in crowns and troughs render such units highly unstable.

The instant manhole guardrail, on the other hand, eliminates the aforementioned difliculties by connecting the rail to the solidly-anchored manhole shield. The manhole shield fits down inside the metal ring bordering the manhole and is securely, although removably, fastened thereto by an inflatable gasket. The metal standpipeforming ring that projects several inches above ground level provides an ideal element to be used for anchoring the guardrail.

The guardrail is equipped with arcuate brackets shaped to engage the outside cylindrical surface of the standpipe portion of the shield and thus leave the entry to the manhole completely unobstructed. The tension element stretched across the free edges of the guardrail end sections at about the level of the entry to the standpipe securely holds these units in assembled relation so that they are not disturbed by wind, accidental bumping and the like. A chain is also preferably fastened across the entry way at a higher level to keep pedestrians from falling into the open manhole. With the guardrail anchored in this fashion, it can be fabricated from lightweight tubular stock which is much easier to handle, yet serves the purpose just as well.

It is, therefore, the principal object of the present invention to provide a novel and improved manhole guard rail.

A second objective of the invention herein disclosed and claimed is the provision of a manhole guardrail specifically designed for use in combination with an upstanding manhole shield of the type removably fastened to the metal ring bordering a manhole.

Another object is to provide a manhole guardrail that is lightweight yet unaffected by wind and accidental bumping when properly anchored to the shield.

Still another objective is the provision of a manhole guardrail that is formed in three foldable sections for easy handling and storage.

An additional object is to provide a unit of the type aforementioned that is held in clamped position encircling the shield by means of a tension member removably fastened between the free edges of the end sections.

Further objects are to provide a manhole shield that is rugged, stable, compact, easy to use, inexpensive, adaptable for use with various types of manhole shields and decorative in appearance.

Other objects will be in part apparent and in part pointed out specifically hereinafter in connection with the description of the drawings that follows, and in which:

FIGURE 1 is a top plan view showing the manhole guardrail of the present invention fastened in place on the standpipe portion of a manhole shield, the latter having been indicated in dotted lines;

FIGURE 2 is a front elevation of the guardrail alone;

FIGURE 3 is an enlarged fragmentary view, portions of which have been broken away and shown in section, revealing the joints that enable the end sections to be folded in upon the center section;

FIGURE 4 is a front elevation similar to FIGURE 2 except that both end sections are shown swung outwardly into alignment with the center section;

FIGURE 5 is a horizontal section taken along line 5-5 of FIGURE 4 showing the shape of the shield-engaging brackets; and,

FIGURE 6 is a fragmentary front elevation showing the manner in which the brackets engage and grip the cylindrical outer surface of the manhole shield.

Referring now to the drawings for a detailed description of the present invention, the manhole guardrail which has been broadly designated by reference numeral 10 will be seen to include a middle or center section 12 hingedly connected on both sides to end sections 14 and 16 that are mirror-images of one another. Each of the end sections 14 and 16 share a common upright 18 and 20 with the center section, the latter elements comprising vertical tubular elements arranged in transversely-spaced parallel relation to one another. Uprights 18 and 20 are each provided with a lower collar 22, middle collar 24 and upper collar 26, all of which are fastened more or less permanently as by welding although rivets or even set screws could be used. Resting atop collars 24 and 26 are short tubular sleeves 28 and 30, respectively, that turn freely on tubular uprights 18 and 20. Tubular sleeves 32, on the other hand, rest against the underside of collars 22 and are similarly rotatable upon uprights 18 and 20. Fixed collars 34 welded or otherwise fastened to uprights 18 and 20 abut the underside of rotatable sleeves 32 and hold them against fixed collars 22. In like fashion, fixed collars 36 fastened to the uprights 18 and 20 holds sleeves 28 against collars 24 as do fixed collars 38 with respect to sleeves 30 and collars 26.

The center section 12 of the guardrail is completed by upper horizontal railing 40 connected between rotatable sleeves 30 middle horizontal railing 42 connected between the middle set of rotatable sleeves 28, and lower horizontal railing 44 interconnecting sleeves 32. The foldable left and right end sections or wings 14 and 16 each include vertical tubular uprights 46 and 48 arranged in spaced parallel relation to one another and to uprights 18 and 20. Upper horizontal railings 50 are connected at their adjacent ends to fixed collars 38 and extend outwardly therefrom to a point of attachment with uprights 46 and 48 near the top thereof. In like fashion, middle railings 52 are connected between fixed collars 36 and uprights 46 and 48 at a point intermediate the ends of the latter. These wings 14 and 16, however, include no lower railing corresponding to railing 44 of the center section but, instead, substitute curved metal brackets 54 therefor that are connected between fixed collars 34 and uprights 46 and 48. These brackets, as will be explained in detail presently, engage the cylindrical outer surface 56 of manhole shield 58 to hold the guardrail in place as shown most clearly in FIGURE 6.

With specific reference to FIGURES 1 and 4, it will be seen that the wings 14 and 16 are very nearly the same width overall as the center section 12 so that when arranged as shown in FIGURE 1, the wings are parallel to one another and perpendicular to the center section thereby providing a guardrail along three sides of the open manhole 60. In order to fold the guardrail for storage, left wing 14 is swung counterclockwise as viewed in FIG- URE 3 through an arc of about 90 up against center section 12 while the right wing 16 is swung in the same direction through a 270 arc until it rests against the back of the center section.

It would, perhaps, be well to mention at this point that the particular arrangement of fixed collars and rotatable sleeves on uprights 18 and 20 can be varied considerably, both with respect to position and with regard to the railing member to which they are fastened, and still preserve the desired foldability of the unit. The particular arrangement shown is, therefore, merely illustrative of one way in which the end sections or wings can be hingedly attached to the center section, there being several others that would immediately occur to those of ordinary skill in the art. There is, however, a reason for locating brackets 54 underneath railing 44 instead of above same as is the case with railing 52 relative to railing 42 and railings 50 with respect to railing 40. As previously mentioned, the instant guardrail was specifically designed for use with the patented manhole shield 58 which, as shown in FIG- URE 6, has a pair of vertically-spaced continuous annular flanges 62 and 64 bordering the upper end thereof which leave only a few inches of cylindrical surface 56 exposed above ground level that are available for engagement by the brackets 54. Also, when so located, bottom railing 44 of the center section 12 fits neatly into the space 66 left between flanges 62 and 64. At first glance, it would appear that brackets 54 would, just as easily, fit into the space 66 between the flanges 62 and 64 while railing 44 passed therebeneath; however, this is not the case because in some oversize manholes, shield 58 is turned upside down leaving gasket 68 exposed which is of lesser diameter and, for this reason, would not mate properly with brackets 54. Cylindrical surface 56, on the other hand, remains exposed in both positions of the shield and enables bracket 4 54 to be shaped to conform exactly thereto. Obviously, when the instant guardrail is used with a non-reversible manhole shield, the above-described refinements may be unnecessary.

Next, with reference to FIGURES 1 and 5, it will be seen that the two shield-engaging brackets 54 are identical and each is fabricated from a length of strap iron. The significant portion of brackets 54 is the arcuate section 70 thereof that is curved on the same radius as the outer cylindrical surface 56 of the shield. The width of the guardrail sections 12, 14 and 1 6 is selected to lie wholly outside shield 58 as shown in FIGURE 1 so that the arcuate sections 70 of the brackets approach the wings 14 and 16 tangentially at about their midpoints. These arcuate sections 70 are approximately 90 in angular extent in the particular form shown which means that the straight portions 72 that interconnect the extremities of the arcuate portion with the respective uprights 38, 46 and 48 extend more or less radially with respect to the center of the shield when in the operative position shown in FIGURE 1.

Finally, with reference to FIGURES 1 and 2, it will be noted that uprights 46 and 48 are each provided With transversely-aligned welded eyes 74 near the lower ends thereof and a tension member 76 with snaphooks 78 on the ends thereof is detachably stretched therebetween to hold the brackets 54 on the wings 14 and 16 in tight engagement with cylindrical surface 56 of shield 58. In the particular form shown in FIGURE 2, tension member 76 comprises an elastic band; however, other types of tension members such as springs and the like will also suffice for this purpose. Another set of eyes 80 are welded to the uprights 46 and 48 near the upper ends thereof to receive the hooks 82 on the opposite ends of chain gate 84. The latter element, of course, guards the open entryway to the manhole and is removed when personnel and equipment are lowered therein.

The sole remaining feature left to be described is that of eyes 86 that are welded atop rails 50 in position to secure a canvas tent flap (not shown). Such a flap can either be laid over the top of the guardrail to prevent rain from entering the manhole or draped down the sides as a wind break.

Having thus described the several useful and novel features of the manhole guardrail of the present invention, it will be apparent that the many worthwhile objectives for which it was designed have been achieved. Although but a single specific embodiment of the invention has been illustrated in the accompanying drawings, I realize that certain changes and modifications therein may well occur to those skilled in the art within the broad teaching hereof; hence, it is my intention that the scope of protection afforded hereby shall be limited only insofar as said limitations are specifically set forth in the appended claims.

What is claimed is:

1. A manhole guardrail for use with a hollow cylindrical manhole shield of the type that is removably fastened inside the ring bordering a manhole and includes a portion projecting upwardly therefrom which comprises: two or more upstanding barrier sections hingedly interconnected to form a fence of a length adapted to partially enclose the manhole shield, said fence having its free ends spaced apart to define an entryway; brackets mounted adjacent the lower edge of the fence in position to engage the shield at opposed points to the right and left of the entryway; and, a tension member adapted to be stretched across the entryway and hold the brackets against the shield.

2. The manhole guardrail as set forth in claim 1 in which: the fence comprises three barrier sections, the two endmost barrier sections each being hingedly connected to a center barrier section on opposite sides thereof for hinged movement about horizontally-spaced substantially parallel vertically-disposed hinge axes.

3. The manhole guardrail as set forth in claim 2 in which: the brackets comprise arcuate members projecting inwardly from the lower extremities of each of the endmost barrier sections, said arcuate members being shaped to conform with the outside cylindrical surface of the shield.

4. The manhole guardrail as set forth in claim 2 in which: each of the barrier sections is substantially planar and rectangular in shape so as to fold into essentially face-to-face parallel relation to one another when not in use.

5. The manhole guardrail as set forth in claim 2 in which: the tension member comprises an elongate elastic band having connectors on opposite extremities thereof adapted for releasable attachment to the free side edges of the endmost barrier sections.

6. The manhole guardrail as set forth in claim 2 in which: means forming an openable gate is connected between the free side edges of the endmost barrier sections spaced above the tension member, said gate-forming means functioning as a removable barrier guarding the open entryway.

7. The manhole shield as set forth in claim 2 in which: the three barrier sections are each substantially planar, rectangular in shape and essentially the same width, the endmost sections being foldable into face-to-face relation against the center section on opposite faces thereof.

8. The manhole shield as set forth in claim 2 in which: each of the endmost barrier sections include a pair of horizontally-spaced vertical uprights interconnected by transverse rail members, and in which the center barrier section comprises horizontally-aligned pairs of sleeves mounted for rotation on the adjacent uprights of the endmost barrier sections and transversely-extending rail elements interconnecting each pair of sleeves.

9. The manhole guardrail as set forth in claim 2 in which: the barrier sections are sized and adapted to form three sides of a circumscribed square with the shield of the center thereof.

10. The manhole shield as set forth in claim 6 in which: the gate-forming means comprises a chain hung between the free side edges of the endmost barrier sections across the entryway.

References Cited UNITED STATES PATENTS 806,160 1 2/1905 Metz. 1,741,323 12/1929 Lufkin .a 9438 1,882,150 10/1932 Kent 94-38 JACOB L. NACKENOFF, Primary Examiner.

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