Патент USA US2405654код для вставки
Aug- 13,_1946- - -J. B. II-IUNTI,‘ SR CONTRACTION JOINT ASSEMBLY , Filed Sept; 16, 1944 ~ $405,654 2- Sheets-Sheet 1 ./. . . ‘ . 7.3”. ' ‘. J23“ '5. HUN-r, .522. ' Aug. 13,"'i94s. v J. B. HUNT, SR ,_ commoner: JOINT ‘ASSEMBLY Filed Sept. 16, 1944 2,405,654 _ ' ' I zsneets-sneet' 2 Patented Aug. 13, 1946 aioatsi * UNITED v STATES FATE Ni‘ lorries ' 2,405,654 CON TRACTION JOINT ASSEMBLY Jesse B, Hunt, Sn, Raleigh, N. (3.. Application September 16, 1944, Serial No. 554,466 2 Claims. 1 This invention relates to new and useful im provements in, contraction joints such as are used in the construction of concrete highways, air (CI. 94-17) 2 elongated rods 3, 8, running longitudinally of the joint. A, plurality of transversely disposed U shaped chairs 9 are disposed transversely of the ports, streets and other paved surfaces. joint, the same passing under the rods 8, with The principal object of the present invention is the rods being welded as at E8 to the inside cor to provide a unitary open-work frame structure ner portions of said chairs 9. for not only properly holding dowel rods in prop The U-shaped chairs 9 each includes a pair erly spaced parallel relation to the sub-grade, of upstanding leg members i I, t2, the leg H be but being so constructed as to spread and thus ing somewhat taller than the leg i2 and having compensate for the contracting action which 10 a circular opening, or in fact, opening of any takes place in concrete. shape and denoted by numeral l3 and conforming Another important object of the invention re with the cross-sectional shape of a corresponding lates to a method of installing dowel bars in con dowel I4. traction or dummy joints in concrete slabs in a The dowel I4 is slipped through the opening 7 more satisfactory manner than is now had with 15 l3 and rests in a crotch in the upper end of the present-day equipment. , Another important object of the invention is to provide for brought to the bled and ready forms with the leg l2 where it is welded inplace as at E5. Alluding further to the U-shaped chair 9, it a rigid assembly which can be can be seen that the intermediate portion of site of the work already assem its horizontal part is crimped or offset upwardly to set on the sub-grade between 20 as at It in the form of an inverted V or some end in View of affording positive other accordion-like spreader and to afford ready and de?nite alignment of the dowels, holding ?exibility at this point it is preferable that the them at a set distance from the sub-grade and chair be longitudinally slotted, as at El, through top of the slab as well as at a positive and de?nite said crimp l6. space between each dowel. 25 It can now be seen, that the joint is placed A further important object of the invention is on the sub-grade 1 in the manner shown in Fig to provide a structure of the character stated ure 1 and the chairs will serve to maintain the which can be easily disposed in place and which dowels Ill in proper parallel spaced relation with remain in a de?nite position during the pouring respect to the sub-grade ‘I. of concrete. 30 If desired, a weakening strip 58 may be em Other objects and advantages of the invention bedded in the upper portion of the concrete pave will become apparent to the reader of the follow ment 6 as shown in Figure 2 immediately above ing description. the crimp I 6 so that the concrete will crack at In the drawings; this point on a straight line. Figure 1 represents a fragmentary sectional 35 It can be seen, that while the concrete is con view through a concrete pavement showing the tracting, there will be a transverse exertion on the joint installed. . joint which will be taken care of by the yield Figure’Z is a sectional view similar to that of ability of the crimps I6 and the fact that the Figure 1 but showing the use of a weakening dowels I4 are slidable through the legs H. strip. 40 The U-shaped chairs are formed of ?at sheet Figure 3 is a fragmentary perspective view of material using a minimum width of 11/2 inches the complete contraction joint assemblage. and when placed in position on the sub-grade act Figure 4 is a fragmentary side elevational view as sand plates and bearing on the sub-grade for looking at one end of one of the U-shaped chairs. adequately and properly supporting the entire Figure 5 is a side elevational view looking at 45 assembly. the opposite end of the chair shown in Figure 4. As evident, the essence of this invention is the Figure 6 is a sectional view through'one of the fact that I am using a self adapting V crimp chairs, the section being on the’ line 6-6 of which will allow the dowel supporting chairs Figure 4. to spread when the concrete contracts at the 50 Referring to the drawings wherein like numer plane of‘ weakness. The V crimp is shown at the als designate like parts, it can be seen that nu bottom of the dowel support. The plane of weak meral 5 generally refers to the improved contrac ness is formed as in Figure 2 by a groove in the tion joint embedded in a concrete pavement or top of the concrete slab over the center of the the like 6 and resting on a sub-grade 7. dowel assembly. This groove allows the concrete The contraction joint 5 consists of a pair of 55 slab to crack in a straight line when the contrac 2,405,654 3 tion takes place. My invention, however, has only to do with the dowel bar and chair assembly. each having one end secured to one end of a cor responding chair and being slidable through the opposite end of said chair. While the foregoing speci?cation sets forth the invention in speci?c terms,‘it is to be understood 2. As a component part of an assemblage of the class described, a U-shaped chair, the hori that numerous changes in the shape, size and ma terials may be resorted to without departing from the spirit and scope of the invention as claimed hereinafter. Having described the invention, what is claimed as new is: v zontal connective portion thereof being provided withan inverted V-shaped spreader, said spread er being of a self-adapting and accommodating type, and a dowel rod, said rod being rigidly con nected at one end to the upper end of one of the» r 1. A contraction joint comprising an elongated 4 ability of said elongated structure, said dowels vertical limbs of said chair, the remaining limb having an aperture therein and the adjacent end of said dowel rod sliding freely through said aper ture. 15 structure including a plurality of transverse ' chairs, said elongated structure being transversely yieldable and dowels supported by said chairs, each of said chairs being provided with ‘an up standing crimp to permit the transverse yield ' JESSE B. HUNT, SR.