US2019793A

US2019793A - Dowel support

Info

Publication number: US2019793A
Application number: US727454A
Authority: US
Inventors: Kenneth C Oelfke
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-05-25
Filing date: 1934-05-25
Publication date: 1935-11-05
Anticipated expiration: 1952-11-05

Description

Patented: Nov; 1935? UNITED .STATES PATENT OFFICE 2,019.19: power. sorron'r Kenneth c. Oelfke, Delmar, N. Y.

Application May 25, 1934, Serial No. 727,454

11 Claims.

My invention relates to concrete paving and more particularly to means for supporting, during the pouring of the concrete, the dowels which are frequently used at the joints between adjacent slabs of the pavement.

In order to eliminate as far as possible the unequal heaving of the slabs of a concrete pavement due to frost or other conditions, it has become customary to require the use of dowels in the pavement at the joints. Such dowels as are used must not interfere with the, relative longitudinal movement of the concrete slab but should prevent relative upward movement of the slabs at the joint. In order to accomplish this, dowels have been designed which have a portion adapted to be embedded in one concrete slab adjacent a joint in the pavement and another portion which extends beneath the adjacent slab. The dowels are usually arranged in pairs, one embedded in each slab and extending under the other slab, and several of these pairs of dowels are spaced transversely of the pavement along the joint, usually two or three feet apart.

Considerable difficulty has been encountered in retaining these dowels in proper position and in proper relation to each other while the concrete is being poured and the usual method of holding the dowels has been to use a separate chair or support for each dowel. Such a chair and the dowel supported thereon is rather easily displaced and the results obtained are far from satisfactory.

The principal object of my invention is to provide a common support for apair of dowels which will hold them in positively fixed relation during the pouring of the concrete but which'will permit relative movement of the dowels in a direction longitudinally of the road as the slabs of concrete with the dowels therein move under the influence of temperature changes. Since it is customary to employ expansion joints between adjacent slabs in a concrete pavement and many of these joints are of the preformed type and serve as an end form for the adjacent slabs, a further object of my invention is to provide a combined-dowel and dowel support which will function also to support a preformed expansion joint during the pouring of the concrete.

With these objects in view myinvention includes the novel elements and the combinations and arrangements thereof described below and illustrated in the accompanying drawing in which- :tlg. 1 is a perspective view of my dowel suppo Fig. 2 is'a perspective view of one of the dowels;

Fig. 3 is a plan view of my dowel support showing one of the dowels in position therein; and

Fig. 4 is a section of Fig. 3 in the plane 4-4 but showing both dowels supported and, in turn, 5 supporting a preformed expansion joint between them.

Referring to the drawing, it may be said that the dowels are generally Z-shaped. That is, they have a portion I which is preferably round and provided with a projection 2 at the end thereof and which is adapted to be embedded horizontally in the slab of the pavement. Each dowel is provided witha base portion 3 which is pref erably flat on its upper side and is adapted to underlie the slab adjacent that in which the portion I is embedded. The upstanding portion 4 is adapted to be embedded in the end of the slab adjacent the joint with its face 5 lying substantially in the plane of the end of the slab. From the brief description 'given above itwill be apparent that/the adjacent slabs may move freely toward each other or withdraw freely away from each other at the joint 6 but that should either slab tend to heave at the joint the portions of the dowels therein which underlie the adjacent slab will also lift that slab. In other words, the adjacent concrete slabs will move up together.

My support is preferably made in the form shown in Fig. l and comprises a metal plate I which may be of l8 gauge black steel shaped as shown so that the blanks therefor may be stamped out of a continuous sheet without wasting material. The sheet I is provided with spaced openings 8 and 9 having straight sides or edges to and H which lie in lines parallel to each other and which .are spaced apart a distance somewhat less'than the thickness of the preformed expansion joint' which it is expected will be used in the pavement. Generally speaking, if a one inch joint is tobe 40 used the edges I 0 and It may lie in parallel lines about A inch apart. Since the dowels which are employed are curved on the back as shown at I! in Fig. 2, the rear edges of the openings 8 and l are preferably curvilinear and may approximate- I 1y fit the curved portion l2 of the dowel. When the dowels are positioned in the plate, the backs thereof lie against the curved rear edges of the openings 8 and 9, as shown in Fig. 4, which serve to maintain the opposed upstanding faces of the dowels in properly spaced relation to receive the expansion joint 6 therebetween. In order to provide for expansion however, it is desirable that when the dowels are inserted in the plate as shown in Figs. 3 and 4 and the back portions I2 of the dowels are in contact with the curved edges of the openings 8 and 9 that there be suflicient clearance, as shown at I3 in Fig. 3 and I4 in Fig. 4, between the front of the dowel and the straight edge of the opening to pennit relative movement between the plate and the dowels in a direction longitudinal of the pavement. Behind each opening 8 and 9 the plate is slitted along the lines I5 and I 6 and holes I! and I8 are punched in the plate of approximately the same diameter as the portion I of the dowel. The tongues I9 and 20 are then struck up vertically from the plate and serve to support the portions I of the dowels, as best shown in Fig. 4. It is understood, of course, that the tongues I9 and 20 are of the proper height to hold the portions I of the dowels substantially horizontal when the portions 3 of the dowels underlie the plate I and in contact therewith as shown in Fig. 4.

In operation the portions 3 of the dowels are inserted in the openings 8 and 9 of the plate and the portions I of the dowel lie on or are supported by tongues I9 and 20. The preformed expansion joint is then inserted between the upstanding portions of the dowels and thus secures the whole in assembled relation. If desired, the plate 'I may be provided with a line of weakness 2|, such as by scoring or perforating, so that it may separate along this line in the event of any undue stress thereon and thus not interfere in any way with the expansion of the pavement at the joint.

While I prefer to support the dowels in pairs, it will be obvious that a single dowel may be supported on the subgrade in proper position for embedding in the slab by breaking the plate I along the line of weakness 2|, shown in Fig. 3, thus forming two separate plates A and B, or the plates may be formed separately in the first instance.

While I have described my invention in its preferred embodiment, it is to be understood that the words which I have used are words of description and not of limitation. Hence, changes within the purview of the appended claims may be made without departing from the true scope and spirit of myinvention in its broader aspects.

What I claim is:

1. In a device of the character described, the combination with a pair of dowelseach having a first portion adapted to be horizontally embedded in a concrete paving slab adjacent a. joint in the pavement and a second portion adapted to underlie the adjacent slab, of a plate provided with spaced openings therein adapted to permit the second portions of said dowels to pass there through and to overlie said portions when the first portions are parallel and horizontal, and means on said plate for supporting said first portions in parallel disposed relation.

2. In a device of the character described, the combination with a pair of dowels each having a first portion adapted to be embedded in a concrete paving slab adjacent a joint in the pavement and a second portion adapted to lie substantially in the plane of the end of the slab, of a plate having portions adapted to underlie each slab at the joint and provided with spaced openings adapted to receive said second portions of said dowels and maintain the same in spaced relation.

3. In a device of the character described, the combination with a pair of dowels each having a first portion ,adapted to be embedded in a concrete paving slab adjacent a joint in the pavement, a second portion adapted to. underlie the adjacent slab, and a third portion adapted to lie substantially in the plane of the end of the slab in which the first portion is embedded, of a plate having portions adapted to underlie each slab 5 at the joint and having spaced openings therein adapted to receive said dowels and secure the same in spaced relation during the pouring of the concrete.

4. A support for a preformed joint in a con- 10 crete pavement comprising a base plate provided with spaced openings therein and adapted to rest on the subgrade for said pavement, a pair of Z- shaped dowels extending through said openings and having the base portionsthereof extending in 15 QDDosite directions and lying under and against said base plate, the upstanding portions of said dowels being spaced in a direction longitudinally of the pavement to permit said preformed joint to be inserted therebetween and secure the whole 2 in assembled relation.

5. In a device of the character described, the combination with a dowel having a portion adapted to be embeded in a concrete paving slab adjacent a joint in the pavement and a portion 25 .adapted to underlie the adjacent slab, of a base plate adapted to rest on the subgrade for said pavement and form a support for said dowel dur-.

ing the pouring of the concrete; said plate having an opening therein through whichthe dowel passes 30 so that the dowel portion adapted to underlie the adjacent slab underlies said plate in contact therewith and the portion adapted to be embedded in said paving slab overlies said plate: and means on said plate for supporting the over- 35 lying portion of said dowel.

6. In a device of the character described, the combination with a pair of dowels each having a first portion adapted to be embedded in a concrete paving slab intermediate the top and bot- 40 tom thereof and adjacent a joint in the pavement, and a second portion adapted to underlie the adjacent slab, of a base plate having portions adapted to underlie each slab at the joint and provided with spaced openings therein adapted g5 to permit said dowels to pass therethrough whereby said dowels are maintained in fixed spaced relation; said plate being provided with a line of weakness between said openings whereby it may break under substantial stress and permit said 50 dowels to move independently of each other.

'7. In a device of the character described, the combination with a pair of.dowels each having a portion adapted to be embedded in a concrete paving slab adjacent a joint in the pavement, a portion adapted to underlie the adjacent slab and an upstanding portion adapted to lie substantially in the end of the slab, of a supporting means for said dowels cooperating with the last mentioned portions thereof to maintain said dowels in spaced relation longitudinally of the pavement and with the first mentioned portions thereof to support the same.

8. In a device of the character described, the combination with a dowel having a first portion adapted to be embedded in a concrete paving slab intermediate the top and bottom thereof adjacent a joint in the pavement, a second portion adapted to underlie the adjacent slab, and a third portion connecting said first and second portions, of a'support comprising a plate-like structure adapted to underlie said slabs and provided with an opening therein adapted to receive the second portion of said dowel, and means for supportplate adapted .to rest on the subgrade for said pavement and form a support for said dowel during the pouring of the concrete; said plate having an opening therein through which the dowel passes so that the dowel portion adapted to underlie the adjacent slab underlies said plate and the portion adapted to be embedded in said paving slab overlies said plate; vand means on said plate for supporting the overlying portion of said I dowel.

10. In a device of the character described, the combination with a pair of dowels each having a first portion adapted to be embedded in a concrete paving slab adjacent a joint in the pavement, 9. second portion adapted to underlie the adjacent slab, and a third portion connecting said first and second portions, of a common supporting means for said dowels cooperating with 5 the first and third portions thereof to maintain said dowels in concrete-embedding position.

11. In a device of the character described, the combination with a pair of dowels each having a first portion adapted to be embedded in a con- 10 crete paving slab adjacent a joint in the pavement, 9. second portion adapted to lie substantially in the plane of the end of the slab and a third portion adapted to underlie the adjacent slab, of a plate-like structure provided with 15 openings therein adapted to receive said second portions of said dowels and cooperating with said dowels to limit the movement thereof longitudinally and transversely of the pavement.

KENNETH CHAS. OILFKE. so