US 1952398 A
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Description (OCR text may contain errors)
J. G. TULLIS March 27, 1934.
ROAD TOOL Filed April 18, 1931 2 Sheets-Sheet 1 March 27, 1934. J G. TULUS 1,952,398
ROAD TOOL Filed April 18, 1931 2 Sheets-Sheet 2 Patented Mar. 27, 1934 ROAD TOOL Jasper G. Tullis, Cleveland, Ohio, assignor to The Cleveland Formgrader Company,
Ohio, a corporation of Ohio Application April 18, 1931, Serial No. 531,049
This invention relates to a tool used in road construction and particularly to a straight edge for gauging the longitudinal evenness and regularity of the surface of concrete pavements.
At present the speeds at which vehicles travel over roads, as well as the loads carried, have greatly increased and as a result the longitudinal evenness and regularity of the road surface is of great importance and the necessity of more pre- 0 cise forming of the contour of the surface is recognized. Slight irregularities or waves in the road surface which are negligibleat slow speeds cause discomfort to passengers of fast moving vehicles and are very dangerous. In the case of heavily loaded vehicles traveling at the higher speeds, the pavement is subjected to very severe impact shocks which are greatly augmented even by slightunevenness in the road surface. It is apparent therefore that more care must be exercised in forming an even pavement surface.
i-feretofore, in the construction of roads, a straight edge of wood or any easily obtained comparatively straight metal member has been generally used. The straight edge, being 10 to 12 feet long, is placed longitudinally of the freshly poured pavement on the portion to be gauged. When this pavement section is brought to the required evenness the straight edge is moved forwardly thereon to dispose about half its length forwardly past the finished portion and over the next succeeding portion, which is then brought substantially even with the working face of the straight edge. Such makeshift straight edges are not sufficiently accurate to obtain the required greater precision now required in this method of constructing and gauging the pavement surface.
It is obvious that the straight edge must be capable of supporting its overhanging length with no warping or bending. Furthermore, since in use the straight edge is often tilted to a certain extent, due to the height'of the operators hands above the pavement, the straight edge must be very rigid laterally so as not to assume an arcuate form when held in the normal operating position.
Again, due to the rough handling of the tool by the workmen, it must withstand severe usage and at the same time maintain its precision.
With these facts in mind, one objectof my invention is .astraight edge for gauging the smoothness or evenness of the pavement surface which has an exceedingly accurate gauge edge or working face, and which is so formed that it will retain a true edge or working face under adverse conditions of use and varying temperatures.
Anotherobject of my invention is a straight edge gauging tool which is very rigid, both longitudinally and laterally, and which will not warp or bend under the usual rough handling.
Another object of my invention is a straight edge comprised of sheet metal and formed so as to most effectively utilize the stock material, thus permitting the use of thin gauge stock with a consequent small total weight.
Another object of my invention is a straight edge of regular contour which may be economically manufactured and assembled from readily available stock material and which may beformed easily with comparatively simple and standard equipment.
Other objects and advantages will become apparent from the following specification in which reference is made to the drawings by the use of reference numerals.
In the drawings--,
Fig. 1 is a perspective view of a straight edge embodying the principles of my invention, showing the manner in which the tool is used.
Fig. 2 is a cross sectional view taken on a plane indicated by the line 2-2 in Fig. '7.
Fig. 3 is a cross sectional view similar to Fig. 2, showing a modified fastening of the upper edges of the stock.
Figs. 4 and 5 are similar sectional views illustrating respectively modified forms of my in vention.
Fig. 6 is a partial cross sectional view taken on a plane indicated by the line 6-6 of Fig. '7.
Fig. 7 is an elevation of the head of the tool.
Referring particularly to Fig. 1 which illustrates a preferred form of my invention, 1 designates the straight edge head to which is attached a handle 2, the handle being sufiiciently long to enable the operator to stand at one side of the pavement and position a straight edge slightly past the center thereof. The distance from the operator to the pavement center is often 12 feet or more, consequently both the handle and the straight edge head must be as light as is conmensurate with strength. Therefore, I prefer to make the handle in the form of a hollow aluminum tube, though other types of handles may be used. The straight edge head comprises a strip of thin gauge metal, preferably aluminumformed into an elongated hollow body 3 having a straight edge or working face 4. The working face is as nearly as possible perfectly straight and flat and is adapted to be placed on the pavement surface to gauge the evenness thereof. This working face is preferably of sufficient width so that it will engage enough surface area of the freshly poured concrete to be supported thereon without indenting the surface to any appreciable amount.
As described, the straight edge head is from to 12 feet in length and supported on a handle midway between the ends. Consequently, due to the overhanging length of the head on each side of the handle it is subjected to the greatest bending stresses near the longitudinal center. The head is made of suficient depth at the central portion to withstand such stresses and is tapered toward the ends, thus forming substantially a constant strength beam which most effectively utilizes the stock material and makes possible the use of less material than otherwise and consequently effects a saving in weight.
Referring particularly to Fig. 2 the head 3 may be formed of a single elongated strip of sheet metal which is somewhat wider near the center than the ends to provide the additional depth at the center. The portion of the metal strip which is to form the working face 4 is held perfectly flat and part of the adjacent side portions are turned upwardly and then inwardly to form a box-like body 3. The marginal portions 5 and 6 of the strip are turned upwardly at an angle to the body 3, as indicated at '7, and are positioned face to face to form an upwardly extending web integral with the body. The upper edge portions 8 and 9 of the marginal areas are pressed firmly together for locking the two marginal portions 5 and 6 against relative movement in any direction, This produces a stiff web Sui-mounting the body 3 and formed of two thicknesses of the metal stock. The web is preferably disposed centrally of the body 3, as illustrated in Fig. 2, and the edge portion 9 extends sufficiently far past the edge portion 8 so that it may be folded over and brought face to face with the surface thereof. In this position these edge portions may be riveted as indicated at 10 or welded or otherwise rigidly secured together to form a bead of greater thickness than the web. In this manner a hollow body 3 having a stiffening web the upper edge of which is a heavy head of at least three thicknesses of metal is formed. The head of the straight edge tool so formed is substantially trusslike in construction, and obviously will withstand severe bending stresses tending to warp it out of the plane of the web. As described, the handle is preferably a tubular metal member. In order to secure the handle firmly to the head 1, I prefer to pass it through the web, as illustrated in Fig. 6, preferably close to the upper surface of the body 3. The end of the handle projecting through the web may be serrated and the serrated portions 11 turned down flatly against the web surface. Suitable plates such as 12 and 13 are placed about the handle on each side of the web, the plate 12 holding the lugs 11 firmly in place against the web and having a central boss 14 extending into the handle post, the web and slightly past the other plate 13. The plates may then be secured together by rivets, as illustrated, or otherwise. This construction provides a very-rigid connection between the head 1 and handle 2.
Lateral braces 15 and 16, shown in Fig. 1, are each secured to the handle near one end, the other end of each being riveted or otherwise fastened to the web of the head 1. These braces preferably are disposed at angles of 45 to the handle and head.
In operation the device is placed on the concrete surface by the operator, while standing at the edge of the roadway, for gauging the smoothness of the finished surface of the concrete either while the surface is plastic and being smoothed or after the same has set or hardened. Though primarily for use only as a gauge, in actual practice workmen will use the same quite often as a spreader or strikeboard when the surface being gauged is in plastic condition, dragging it across such surface to remove very light surface irregularities. This action tends to cause horizontal as well as vertical bends in the head. To furnish additional rigidity for withstanding these stresses I may form each of the marginal portions 5 and 6 with a plurality of outwardly extending ribs 1'? which may be pressed into the metal during the forming operation. These ribs may extend in a generally vertical direction. The web may be additionally stiffened by similarly pressed longitudinally extending ribs 18. The straight edge thus formed is very rigid and will with= stand severe bending and torsional strains and yet will maintain a true working face.
Furthermore, the head is of regular contour and consequently may be easily formed by stamping and pressing. The completed head contains no metal which has been subjected to severe stresses or bends which are apt to set up internal stresses tending to warp the working face when the straight edge is exposed to changes in tem-. perature or is heated. Such an advantage is important inasmuch as pavements are to be held within limits of one quarter of an inch or less to the true surface.
In Fig. 3 a. similar form of head is shown with the exception that the upper edge portions of the marginal areas 5' and 6' are folded in a different manner; the marginal edge 9' being turned to form a somewhat cylindrical bead which will be 115 more rigid than the bead described in connection with the form of Fig. 2.
In Fig. 4 is illustrated another satisfactory manner of forming the head which, however, has some disadvantages over the forms previously 1 2 0 described. As there illustrated the working face of the desired width is held fiat and the adjacent areas 21 and 22 are turned upwardly to form a head of triangular cross section, the upper edge portions being folded together as indicated at 23. This form may likewise have longitudinal and vertical strengthening ribs 24 and 25 respectively. This form has an advantage in that it is more easily pressed into shape. In some cases it is permissible to use a straight edge having 'a working face which is arcuate in cross section, in which case the form illustrated in Fig. 5 may be used. In this form the body 26 is circular in cross section, the web 2'? being formed as previously described, and the upper edge portions interlocked or secured together or both.
It is apparent from the above description that I have provided a very simple and economically formed straight edge which will maintain a true working surface even when subjected to very 140 sever usage and varying temperatures and that I have very effectively disposed the stock material so as to provide very great strength with minimum weight.
1. A straight edge tool, comprising an elongated hollow sheet metal body member, means surmounting said body and comprising two longitudinal web elements, each of said elements being a continuation of the metal stock of which the 150 body member is formed, and of greater depth at the center portion than at the end portions, means for securing said web elements in fixed relation to each other whereby an upwardly extending stiffening web member of greater depth at the center portion and tapering toward the ends of the body member is provided, and an elongated operating handle secured to one of said members in said center portion and extending laterally therefrom.
2. A sheet metal straight edge comprising a hollow body substantially closed at the top and surmounted by a web of two layers of the stock metal, the upper portion of one layer of the web being bent over the upper portion of the other layer and forming a bead of three layers of metal, said web layers being rigidly fixed in position relative to each other, said bead stiffening said web for rendering the straight edge rigid against bending normal to the web, and an operating handle secured to said web intermediate the body and bead.
3. A road tool for the purpose described, comprising an elongated hollow body having a longitudinally extending web for increasing the rigidity of said body, an elongated operating handle for said tool, one end of said handle protruding through said web, and the handle extending laterally from the plane of the web, a shoulder on the protruding end of said handle in abutting relationship with a face of the web, and means for holding said handle with the shoulder firmly abutting said web face, said means comprising a cap engaging the exposed face of the shoulder and abutting said web face, and means for securing the cap to the web whereby the handle is secured in place.
4. A road tool for the purpose described, comprising a hollow body having a longitudinal reinforcing web, an elongated operating handle for said straight edge extending laterally from the web and having one end protruding therethrough, said end having an axial bore and means to secure the handle in rigidly fixed position to the web, said means including a shoulder on the protruding end of the handle abutting the web face, a cap adapted to lie over the shoulder and to engage the web for holding the shoulder firmly in abutting relationship thereto, a boss on said cap engaging said bore and fitting tightly therein when the cap is secured in place over said shoulder, said boss protruding past the opposite face of said web, and means for securing said cap to the web.
JASPER. G. TULLIS.