US 1382106 A
Description (OCR text may contain errors)
P. A. McKENZlE.
APPLICATION FILED MAYI3. 1920.
1,382,106, Patented June 21, 1921.
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PHILIP A. MCKENZIE, OF HOUSTON, TEXAS.
Application filed. May 13, 1920.
To aZZ to 710m it may concern:
Be it known that I PHILIP A. MCKENZIE, a citizen of the United States, residing at Houston, in the county of Harris and State of Texas, have invented certain new and useful Improvements in Bridge Construction; and I do declare the following tobe a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.
This invention relates to improvements in bridges and it has more particular reference to one which is especially designed for placement over gutters, ditches, and the like, it being such that it is adaptable as a foot bridge or as a vehicle bridge.
The object of the invention is to provide a bridge of extreme simplicity and durability which is of such construction that it may be easily and readily placed inposition by persons unskilled in bridge construction.
Other objects and advantages of the invention will be apparent during the course of the following description.
In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,
Figure 1 is a top plan view, partly in section, of a bridge constructed in accordance with my invention.
Fig. 2 is a longitudinal sectional view thereof, showing it in use.
Fig. 3 is a transverse section taken on the line 3-3 of Fig. 2.
Fig. at is a detail perspective view of one of the concrete slabs.
Fig. 5 is a perspective view of a slightly modified form of the invention.
In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral 1 is employed to designate what I Shall term girders for the sake of explanation. I emplcy a plurality of these girders, there being two used in the type of bridge shown in Figs. 1 and 2. Each one is made from concrete, is rectangular in cross section and is provided at each end with an upstanding lug 2. I also employ a plurality of concrete slabs 3 each of which is recessed at its opposite ends to provide shoulders 4:, which, when in use, rest against the inner faces of the girders 1 while the reduced end per- Specification of Letters Patent.
Patented June 21, 1921.
Serial No. 381,119.
tions 5 rest on the upper fiat faces of the girders. This construction retains the girders in spaced relation when the bridge is erected and preventsthem from moving inwardly. In use, the outermost slabs 3 abut the lugs 2 and are thereby prevented against lateral displacement.
To prevent possible breakage of any of the parts of my bridge, I embed metal reinforcing rods 6 in both the. girders and slabs. In the girders I bend the ends of the rods 6 upwardly into the lugs 2 as indicated at 7. This arrangement guards against breakage of the lugs. It is to be noted that the rods 6 are embedded in the slabs at a point be tween the middle and the bottom so as to reinforce that part of the slab which receives the greatest strain and is most liable to break. It is also to be noted that the ends of these rods are bent vertically at 8 and then horizontally at 9 so as to extend into and reinforce the reduced ends 5 of the slabs. This construction is exceedingly strong and will withstand great strains.
I have shown two different types of bridges in the drawings. In Figs. 1 and 2 the bridge shown is especially adapted for use as a foot bridge. On the other hand, by increasing the size of the parts of my bridge and arranging them in the manner shown in Fig. 5, Ihave a bridge which is ideal for use as a driveway for vehicles. Close examination of both forms of the invention shown will disclose the fact that the construction of the slabs and girders is the same in both cases, the only difference between the two being the manner in which they are arranged. For instance in the foot bridge construction the slabs are arranged longitudinally so'as to extend crosswise of the ditch while in the other form they are arranged to extend longitudinally of the ditch; theretore, the difference between the two forms of the bridge is a mere reversal of parts which, when done, adapts the bridge for a different purpose.
The manner in which my bridge is erected is thought to be obvious from the foregoing description. It is therefore deemed unnecessary to prepare a description thereof.
While I have described my bridge as being adaptable for placement over gutters and ditches, I desire it to be understood that it may be used for any number of different purposes.
From the foregoing de cripti n tak n in connection with the accompanying drawings, it is believed that persons skilled in this line of Work, will be able to obtain a thorough understanding of the invention.
I claim: V
1. A pre-cast bridge for placement over a gutter comprising a plurality of' concrete girders, each of which is provided at its opposite ends with an upstanding lug, and a plurality of concrete slabs associated with the girders, each slab having its bottom face recessed at its opposite ends to provide shoulders which abut the vertical inner faces of the girders the reduced end portions of the slabs resting on the upper faces of the girders and the outermost slabs bearing against the. aforesaid lugs.
2. A pre-cast bridge for placement over a gutter comprising a pair of rectangular concrete girders of uniform thickness throughout their lengths, being provided at rality of rectangular concrete slabs associated with the girders, "said slabs being of the same thickness as the girders and having their underfaces notched at their opposite ends to simultaneously provide shoulders abutting the vertical inner faces of the girders, and reduced end portions resting on the upper faces of the girders said reduced ends being of a thickness equal to the height of the lugs to render their upper faces flush with the upper ends of said lugs,
the outermost slabs bearing against the aforesaid stops to hold the slabs together. In testimony whereof I have hereunto set my hand.
Prnmr A; MCKENZIE.