The present disclosure relates generally to slab bolster uppers that support rebar enforcements in a concrete form, and more particularly to interconnecting slab bolster uppers that utilize a snap-fit connection.
Reinforced concrete typically includes steel rebar reinforcement that is held within the concrete mold by supports commonly known as slab bolster uppers. Slab bolster uppers, which may be plastic or metallic, come in a variety of heights so that the user can position the rebar at a selected location within the mold before the concrete is poured. In addition to a variety of heights, slab bolster uppers may be provided in fixed lengths, and placed end to end at the concrete forming site when the dimensions of a given concrete mold are greater than the length of one slab bolster upper. The industry has seen fit to provide strategies for joining slab bolster uppers end to end to provide a continuous rebar support surface across a complete dimensional span of the concrete mold. Unfortunately, many of these end to end joining strategies suffer from a variety of drawbacks, including but not limited to introducing a weak spot where the slab bolster uppers are joined that can be easily broken. In addition, many connection strategies permit some swiveling about the connection location that can undermine the ability to lay out the precise grid of rebar supports in a given concrete mold. Other strategies inhibit the ability of joined slab bolster uppers to be easily moved and relocated in a mold area prior to the concrete being poured.
The present disclosure is directed toward one or more of the problems set forth above.
In one aspect, a plurality of slab bolster uppers include a first slab bolster upper that is identical to a second slab bolster upper. Each includes a body having a rebar contact surface separated a height distance from a ground contact surface along a vertical axis. The rebar contact surface extends from a first end to a second end of the body along a horizontal axis. The first end terminates at a first vertical planar abutment surface that is one side of a thickness profile. The second end has a different shape than the first end, and includes a second vertical planar contact abutment surface, and includes a snap-fit connector shaped to receive the thickness profile of the first end. The first and second slab bolster uppers are movable from a disconnected configuration to a connected configuration exclusively responsive to sliding the second end of one of the bolsters relative to the first end of the other slab bolster upper along the vertical axis while the respective second vertical planar abutment surface is in contact with the respective first vertical planar abutment surface.
In another aspect, a method of joining a first slab bolster upper to a second slab bolster upper includes positioning the first slab bolster upper and the second slab bolster upper in a disconnected configuration. The second slab bolster upper is moved relative to the first slab bolster upper from the disconnected configuration to a connected configuration that is characterized by respective horizontal axes of the first and second bolster uppers being coincident. The moving step includes sliding a second vertical planar abutment surface of the second slab bolster upper along a vertical axis relative to, and in contact with, a first vertical planar abutment surface of the first slab bolster upper. During this process, a thickness profile of one end of the first slab bolster upper is received into a snap-fit connector of the second slab bolster upper. The first vertical planar abutment surface is a terminal end of the first slab bolster upper.
Referring now initially to
Referring now in addition to
In the illustrated embodiment, the snap-fit connector 31 includes the body 20 defining a pair of grooves 33, 34 that receive respective portions 28, 29 of the thickness profile 27. The pair of grooves 33, 34 and the respective portions 28, 29 of the thickness profile 27 are located on opposite sides 40, 41 of a plane 52 that is defined by the vertical axis 50 and the horizontal axis 51. The grooves 33 and 34 have a width that matches, and is sized to receive, the thickness of thickness profile 27. The bottom surfaces of grooves 33 and 34 are at an angle 55 with respect to one another that is bisected by the vertical axis 50. This angle 55 matches the angle defined by the outer edges of the thickness profile 27. In this way, when the thickness profile 27 is received into grooves 33 and 34, the two slab bolster uppers 11 and 12 are held snuggly together with first vertical planar abutment surface 26 at end 24 held abutting second vertical planar abutment surface 30 of the second end 25. By holding the two planar abutment surfaces 26 and 30 in contact, swiveling of one slab bolster upper 11 relative to the other slab bolster upper 12 about any axis perpendicular to horizontal axis 51 is prevented. In addition to the planar abutment surfaces 26 and 30 being abutting each other, the outer edges of thickness profile 27 abut the counterpart bottom surfaces defined by grooves 33 and 34. In this way, the two parts, when in a connected configuration 16, have contact with one another in at least three distinctive and non-contiguous planes.
Although not necessary, the snap-fit connector 31 of the present disclosure is preferably a permanent snap-fit connector 32. A permanent snap-fit connector according to the present disclosure means that surfaces on each of the components arrive in a position opposite each other that blocks the snap-fit connector from being moved from a connected configuration 16 to a disconnected configuration along a same pathway to which the component parts moved in order to arrive at the connected configuration. In this case, the permanent snap-fit connector 32 is made permanent due to the inclusion of a pair of catch surfaces 36 that are oriented perpendicular to the vertical axis 50 and located on the opposite sides 40 and 41 of a plane defined by the vertical axis 50 and the horizontal axis 51. The pair of catch surfaces 36 block the snap-fit connector 31 from moving from the connected configuration 16 toward a disconnected configuration. In particular, the top surface 35 of the grooves 33 and 34 snaps into a position abutting catch surfaces 36 at the connected configuration 16.
Although the slab bolster uppers 11, 12 of the present disclosure could be manufactured from metal, each of the identical slab bolster uppers 11, 12 preferably consists solely of a single integral piece of molded plastic 17 that includes all the features previously described including, but not limited to the rebar contact surface 21, the ground contact surface 23, the intermediate scaffolding, along with the snap-fit connector 31 and its counterpart thickness profile 27 at opposite ends.
As best shown in
Those skilled in the art will appreciate that the material out of which the slab bolster uppers 11 and 12 is made should be sufficiently strong to support the heavy load of multiple rebar reinforcements resting atop rebar contact surface 21, but sufficiently flexible to permit some de minimis deformation at snap-fit connector 31 without breaking. In one specific example, slab bolster uppers 11, 12 may be injection molded from ABS plastic material.
The present disclosure finds general applicability to support rebar in a reinforced concrete mold. In particular, the present disclosure permits multiple identical slab bolster uppers to be connected end-to-end to accommodate any sized concrete mold dimensions. Thus, the slab bolster uppers 11, 12 can be provided to a worksite in a box containing numerous identical slab bolster uppers. Furthermore, the snap-fit connector of the present disclosure is preferably sufficiently secure that a plurality of connected slab bolster uppers may be lifted, moved and otherwise relocated in a mold location without worry of pivoting and/or twisting between any two of the slab bolster uppers 11, 12.
Referring again to
Although not necessary, the ornamental design of a slab bolster upper according to the present disclosure is illustrated in the various views shown in
The present description is for illustrative purposes only, and should not be construed to narrow the breadth of the present disclosure in any way. Thus, those skilled in the art will appreciate that various modification might be made to the presently disclosed embodiments without departing from the full and fair scope and spirit of the present disclosure. Other aspects, features and advantages will be apparent upon an examination of the attached drawings and appended claims.
Number | Name | Date | Kind |
---|---|---|---|
4019298 | Johnson, IV | Apr 1977 | A |
4942714 | Langley, Jr | Jul 1990 | A |
5664390 | Sorkin | Sep 1997 | A |
6735918 | Haslem et al. | May 2004 | B2 |
6775954 | Sorkin | Aug 2004 | B1 |
D621239 | Sorkin | Aug 2010 | S |
10106985 | Waldner et al. | Oct 2018 | B1 |
10329768 | Verelli | Jun 2019 | B2 |
20060096197 | Tollefson | May 2006 | A1 |
20080060294 | Cox et al. | Mar 2008 | A1 |
20080184656 | Lee et al. | Aug 2008 | A1 |
20170260770 | Xu | Sep 2017 | A1 |
20210108414 | Cross | Apr 2021 | A1 |
Number | Date | Country |
---|---|---|
2975189 | Jan 2016 | EP |