US2285004A - Manhole step - Google Patents

Description

June 2, 1942.

H. BARRIBALL MANHOLE STEP Filed March 6, 1939 Ease-er #5923186.

ATTORNEYS.

Patented June 2, 1942 UNITED stares ram OFFICE Claims.

This invention relates to an improved form of step for man-hole wall.

Heretofore there have been such steps made of bars or rods of substantially U-shape with their ends extended through the wall and secured to the opposite side thereof. Such an arrangement requires special provision for the insertion of the step in the wall and involves correspondingly special labor with the expense incident thereto. Furthermore, such a step would deteriorate because of the natural elements to which it was subjected at all times; and thus over a long period of time, it could not be considered dependable. Also, the removal and renewal of such a step would require again considerable labor and thus this old arrangement has proved quite expensive and unsatisfactory. It might be added that such a step, in order to be at all dependable even for any time after installation, would have to be made of comparatively large stock of bar or rod because:

of the force applied thereto in ordinary usage, it being obvious of course that such a step must be able to withstand the load without danger of stood to include also all of the several specific features of construction and arrangement of parts as hereinafter described and claimed.

Fig. 1 is a top plan view of my improved form of step;

Fig. 2 is an end view thereof Fig. 3 is a partial plan view illustrating how my step is employed;

Fig. 4 is a front elevation illustrating the same thing; and

Fig. 5 is a partial view of the deformed reinforcing bar.

It is to be understood that the present form of disclosure is merely for the purpose of illustration and that there may be devised various other forms thereof without departing from the spirit of my invention as herein set forth and claimed.

As above stated, my present form of step is molded out of concrete and thus it becomes a selfcontained, one-piece body. According to one form and size of step which I have made and demonstrated with very marked success and satisfaction for all required purposes, it is thirteen inches long and ten inches wide, from front to rear, with approximately four inches thereof inserted within the man-hole wall and the remaining portion of approximately six inches extending from the front of the wall, as indicated in Fig. 3. The measurement of thirteen inches corresponds to that of one and one-half bricks as stretchers or three as headers; while the depth of four inches to which the step is inserted in the wall, corresponds approximately with half-length of brick; and the height of the step is made to correspond approximately with the thickness of a brick, about two and one-half inches. Thus my step can be quite readily built up in the brick wall in much the same manner as if it were part of the brick work, the motor being applied to those surfaces thereof which come at the regular joints between the bricks.

As a further means of strengthening the bond between the step and the wall to which it is applied I have provided an indenture upon the top surface thereof within the area to be inserted within the wall of the man-hole, such indenture being indicated by reference numeral 2, which is adapted to receive the mortar when the step is employed in connection with a brick wall, thereby strengthening the engagement of the step within the wall. Such indenture may also be inindenture means, above referred to, and allowed to set and become solidly fixed therewithin.

This step comprises the rear portion I which is adapted to be set within the man-hole wall, the side portions 4 and the front tread portion 5 which extends across the front ends of the side portions. That is, the side and front portions are provided by the cut-out portion or opening 6 which in the present illustration is of oblong form with rounded ends, this space or openin being essential to accommodate the front part of the foot of the user as it is applied to the front or rung portion 5. The sideportions 4 are reinforced by means of the raised ribs 1 which serve also as a meansof preventing accidental dislodgement of the foot of the user laterally from the rung 5. The rung is corrugated, as indicated in the drawing, so as to afford an efficient surface engagement 'by th foot of the user. The corner portions 8 and 9 serve also as a means of further strengthening the side portions 4, especially the corner portions which are adjacent to the rear portion I.

As a means of reinforcing the side and front portions of this step, I have embedded the deformed bar of approximately three-eighths of an inch in diameter in the present design of step and with the other dimensions as above noted.

This deformed reinforcing bar is here indicated by reference numeral H] and is of substantially U-shape which corresponds to the relative arrangement of the side and front portions of the concrete molded form, as indicated in Fig. 1. This reinforcing bar is arranged in an inclined manner with its rear ends at a higher level than the front part thereof, as indicated in Fig. 2. That is, the side portions of this bar incline downwardly and forwardly, and the front or middle portion thereof occupies position at about mid-way of the height of the rung portion, as also indicated in Fig. 2.

As indicated in Fig. 3, the step is inserted into the wall up to a point corresponding approximately with the rear edge of the opening 6. In fact, in the present illustration this point is slightly to the rear of the opening 6 although such variation is not material. As a matter of fact, this line of engagement at the front of the wall will be different when the step is set in a curved form of man-hole wall. In such a case, I am able to employ the same form of step as in the form of wall herein illustrated. Y

The side and front portions of this step will, of course, be subjected to the loadincident to actual usage and I have found from actual experiment that my present form of step can Withstand considerably greater load than required and without even cracking. My belief is that such strength is due to the particular manner in which the reinforcing bar is arranged, as herein indicated. Although I do not wish to be bound by my present theory as to why this arrangement contributes such great strength, yet my understanding is that there will be a longitudinal thrust along the bar towards the front thereof when load is applied thereto and there will at the same time be a compression of the concrete beneath the bar in the region of the side portions 4 and compression of the concrete above the bar in the region to which the load is applied upon the tread portion. As a result, the bar is prevented from bending under the load to which it will be subjected; and, as above stated, the concrete will not even crack under even greater load than that ordinarily to be expected during regular usage.

Thus, I have devised a man-hole step which requires the use of" considerably less steel and which consequently is less expensive but which is stronger, more dependable and hence more practical, as compared with previous forms of such devices.

What I claim is:

1. A device of the character described comprising a base having substantially parallel top and bottom sides, arms extending laterally from the ends of the base and whose top surfaces are inclined downwardly from the corresponding surface of the base towards their outer ends the bottom surfaces of said arms occupying the same plane as the bottom side of said base, a cross bar connecting the outer ends of said arms and being of substantially the same vertical dimension as the adjacent portions of said arms, flanges extending along the top sides of the arms and whose top surfaces are substantially flush with the corresponding surface of the base, the foregoing elements constituting parts of an integral body of earthenware, and a reinforcing element embedded within said body and extending lengthwise through the cross bar at about mid-height thereof and inclined upwardly therefrom through the arms and into the base.

2. A device of the character described comprising a base having substantially parallel top and bottom sides, arms extending laterally from the ends of the base the bottom surfaces of said arms occupying the same plane as the bottom side of said base, a cross bar connecting the outer ends of said arms, the foregoing elements constituting parts of an integral body of earthenware, and a reinforcing element embedded within said body and extending lengthwise through the cross bar at a level nearer the bottom plane than the top plane of the base and being inclined rearwardly through said arms and into the base toward the plane of the top of the base.

3. A device of the character described comprising a base having substantially parallel top and bottom sides, arms extending laterally from the ends of said base, the bottom surfaces of said arms occupying the same plane as the bottom side of said base, a cross bar connecting the outer ends of said arms and being of less height than said base, upward projections upon the top sides of said arms to prevent accidental lateral dislodgement of the users foot from said cross bar, the foregoing elements constituting parts of an integral body of earthenware, and a reinforcing element embedded within said body and extending lengthwise through said cross bar at a level nearer the bottom plane than the top plane of said base and being inclined rearwardly through said arms and into said base towards the top of said base.

4. A device of the character described comprising a base having substantially parallel top and bottom sides, arms extending laterally from the ends of said base, the bottom surfaces of said arms being in the same plane as the bottom side of said base, the top surfaces of said arms being inclined downwardly and forwardly from said base, a cross bar connecting the outer ends of said arms and being. of substantially the same height as the forward ends of said arms, the foregoing elements constituting parts of an integral body of earthenware, and a reinforcing element embedded within said body and extending lengthwise through said cross bar at approximately mid-height thereof and being inclined upwardly and rearwardly through said arms and into said base towards the top thereof.

5. A device of the class described comprising a base having substantially parallel flat top and bottom sides, arms extending laterally from the ends of said base and Whose bottom surfaces are in the same plane as the bottom side of said base, a cross bar connecting the outer ends of said arms and being of less height than said base, the foregoing elements constituting parts of an integral body of earthenware, and a reinforcing element embedded within said body and extending lengthwise through said cross bar and rearwardly through said arms and into said base.

ROBERT H. BARRIBALL.

Images