Patent Publication Number: US-11384548-B2

Title: Sleeve for concrete slab penetration

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims the benefit of priority to U.S. Provisional Patent Application No. 62/833,592, filed Apr. 12, 2019, entitled “SLEEVE FOR CONCRETE SLAB PENETRATION,” the contents of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The proper formation and alignment of concrete slabs is critical in today&#39;s high rise construction industry. While concrete slab formation techniques have enjoyed progressive improvement, room for improvement still exists. For example, it can be difficult to identify small variations in the alignment of concrete slabs distributed across multiple floors of a multi-floor building and these variations have the potential to impact the alignment of other structural components of the building. There is also room for improvement in the measuring of the alignment of concrete slabs distributed across multiple floors. For at least these reasons, apparatuses and methods for improving the formation of concrete slabs are desirable. 
     SUMMARY OF THE INVENTION 
     This disclosure describes various methods and apparatus to aid in the formation and alignment of concrete slabs. In particular, a sleeve for forming a tapered channel extending through a concrete slab is described. 
     Various sleeves are described for forming a channel through a concrete slab. In some embodiments, the sleeve may include a sleeve body having a top end and a bottom end extending along a longitudinal axis, wherein the top end has a first cross-sectional area perpendicular to the longitudinal axis and the bottom end has a second cross-sectional area perpendicular to the longitudinal axis. The first cross-sectional area of the top end may be greater than the second cross-sectional area of the bottom end. In some embodiments, the sleeve may include an attachment flange attached to the bottom end of the sleeve body. In some embodiments, the attachment flange may extend laterally outward from the bottom end with respect to the longitudinal axis, the attachment flange being configured to facilitate attachment of the sleeve body to a concrete form. 
     In some embodiments, the sleeve body is tapered between the top end and the bottom end, such that a cross-sectional area of the sleeve body perpendicular to the longitudinal axis incrementally decreases from the top end to the bottom end. 
     In some embodiments, the attachment flange extends along a plane perpendicular to the longitudinal axis. In some embodiments, the attachment flange has a cross-sectional area perpendicular to the longitudinal axis that is greater than a cross-sectional area of the sleeve body at the bottom end. In some embodiments, the cross-sectional area of the attachment flange is greater than the cross-sectional area of the sleeve body at the top end. 
     In some embodiments, the sleeve body has a cone-shaped geometry, and wherein the attachment flange has a circular geometry that extends radially outward from the bottom end with respect to the longitudinal axis. In some embodiments, cross-sections along the sleeve body perpendicular to the longitudinal axis are circular. Alternatively, the cross-sections may be elliptical, rectangular, triangular, or may be of any other suitable shape. 
     In some embodiments, the sleeve body is hollow, such that the sleeve body defines a channel, the longitudinal axis extending through the channel. In some embodiments, the sleeve body includes an optically transparent or translucent portion configured to permit an optical beam to pass therethrough. In some embodiments, the attachment flange includes one or more fastener openings, each configured to receive a screw, a nail, or a bolt for affixing the attachment flange to a wall of the concrete form. 
     In some embodiments, the sleeve body is formed from a hardened polymer material. In some embodiments, the sleeve body includes a high density polyethylene (HDPE) material. 
     The disclosure describes example methods for using sleeves for alignment. In some embodiments, concrete slabs of a building structure may be aligned using a sleeve. Methods in these embodiments may include positioning an optical beam source on a first floor of a building structure; causing the optical beam source to emit an optical beam toward a first location of a concrete form of a second floor; forming an opening in the concrete form of the second floor at the first location; and disposing a first sleeve at the first location. The first sleeve may include a sleeve body having a top end and a bottom end extending along a longitudinal axis, wherein the top end is wider than the bottom end. The first sleeve may further include an attachment flange attached to the bottom end of the sleeve body, wherein the attachment flange extends laterally outward from the bottom end with respect to the longitudinal axis, the attachment flange being configured to facilitate attachment of the sleeve body to a concrete form. The method may further include securing the first sleeve to the concrete form of the second floor at the first location; pouring a first concrete mixture into the concrete form; allowing the first concrete mixture to at least partially harden around the first sleeve; and removing the first sleeve so as to leave behind a first tapered channel in the first concrete mixture. 
     In some embodiments, the method may further include orienting the optical beam such that the optical beam is perpendicular to the first floor; and confirming that the optical beam travels through the first tapered channel such that the optical beam is perpendicular to the second floor. 
     In some embodiments, the method may further include causing the optical beam to travel through the first tapered channel toward a second location of a concrete form of a third floor; forming an opening in the concrete form of the third floor at the second location; and securing a second sleeve to the concrete form of the third floor at the second location. The method may also include removing the second sleeve so as to leave behind a second tapered channel; and confirming that the optical beam travels through the first tapered channel and the second tapered channel. 
     In some embodiments, the method may further include positioning, through the first tapered channel, a tapered plug dimensioned to fit at a bottom of the first tapered channel; and pouring a second concrete mixture into the first tapered channel. 
     In some embodiments, the optical beam source may be a laser. In some embodiments, securing the first sleeve includes inserting one or more screws into one or more fastener openings of the attachment flange. In some embodiments, removing the first sleeve includes breaking the sleeve body. 
     In some embodiments, a sleeve may include a sleeve body having a first end and a second end wider than the first end, and an attachment mechanism protruding from the first end of the sleeve body. The attachment mechanism may be configured to facilitate attachment of the sleeve body to a concrete form. In some embodiments, the sleeve may include a removal mechanism disposed at the second end of the sleeve body, the removal mechanism being configured to facilitate removal of the sleeve body from the concrete slab. 
     In some embodiments, the sleeve may have a cone-shaped geometry, a cylindrical geometry, a pyramidal geometry, a cuboidal geometry, or any other suitable geometry. In some embodiments, the sleeve body includes a base portion having a cylindrical geometry at the first end of the sleeve body, the base portion being integrally formed with a tapered portion having a conical frustum geometry. In some embodiments, the base portion has a height of between 0.5 and 1.0 inches. 
     In some embodiments, the sleeve body defines a channel, a longitudinal axis of the sleeve body extending through the channel. In some embodiments, the attachment mechanism includes a bolt extending through the channel. In some embodiments, a portion of the attachment mechanism protruding from the first end of the sleeve body is a threaded end of the bolt. 
     In some embodiments, the attachment mechanism includes a handle disposed at the second end of the sleeve body. 
     In some embodiments, the sleeve body is formed from a hardened polymer material. 
     Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1  shows a perspective view of a reusable sleeve that includes a sleeve body and an attachment mechanism; 
         FIG. 2  shows a cross-sectional side view of the sleeve body depicted in  FIG. 1 ; 
         FIG. 3A-3F  show a number of cross-sectional side views of the reusable sleeve depicted in  FIGS. 1 and 2  installed on a wall of a concrete form during formation of a concrete slab; 
         FIG. 4A  shows an alternative embodiment in which, a sleeve body encloses a head and an upper portion of a bolt; 
         FIG. 4B  shows another alternative embodiment in which a sleeve body includes extensions for adapting the sleeve body to concrete slabs of different thickness; 
         FIG. 5  shows a perspective view of a one-time use sleeve suitable for forming a hole in a concrete slab; 
         FIG. 6A  shows a perspective view of another one-time use sleeve; 
         FIG. 6B  shows cross-section schematics of different example embodiments of the sleeve in  FIG. 6A ; and 
         FIGS. 7A-7F  show a series of illustrations demonstrating a use case for the sleeves described herein. 
         FIG. 8  illustrates an example method for aligning concrete slabs of a building structure. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     Representative applications of methods and apparatus according to the present application are described in this section. These examples are being provided solely to add context and aid in the understanding of the described embodiments. It will thus be apparent to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the described embodiments. Other applications are possible, such that the following examples should not be taken as limiting. 
     In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, it is understood that these examples are not limiting; such that other embodiments may be used, and changes may be made without departing from the spirit and scope of the described embodiments. 
     Sleeves for forming holes in concrete slabs can take many different forms and sizes. The present application describes both reusable and non-reusable sleeves. As described in further detail herein, the sleeves can have an inverted tapered geometry that helps facilitate removal of the sleeve from a concrete slab following formation of the concrete slab. The sleeves also include some kind of attachment mechanism for securing the sleeve to a concrete form. This allows a position of the sleeve and the resulting whole it forms to be fixed with respect to the concrete slab. 
     These and other embodiments are discussed below with reference to  FIGS. 1-8 ; however, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1  shows a perspective view of a reusable sleeve  100  that includes a sleeve body  102  and an attachment mechanism  104 . Sleeve body  102  can include a tapered portion  106  and a base portion  108 . In some embodiments, tapered portion  106  can have a frusto conical geometry as depicted; however, other variations are possible. More generally, a geometry of tapered portion  106  can have any symmetrical frustum shape, such as a pentagonal or square frustum. Base portion  108 , as depicted has a cylindrical geometry  108 ; however, a geometry of base portion  108  can also match the geometry of any of the various shapes described above for tapered portion  106 . Attachment mechanism  104  can take the form of a bolt that extends through at least a portion of sleeve body  102 . In some embodiments, attachment mechanism  104  can extend all the way through sleeve body  102 . 
       FIG. 2  shows a cross-sectional side view of sleeve body  102 . In particular, a channel  202  is shown following a longitudinal axis  204  of sleeve body  102 . As depicted, opposing ends of channel  202  can be enlarged to accommodate a bolt head and nut of attachment mechanism  104  (not depicted).  FIG. 2  also depicts how an end of tapered portion  106  joined to base portion  108  can have a very gradual taper with a fixed slope. In some embodiments, angle  206  can be between about 85 and 88 degrees. In some embodiments, angle  206  can be 86.6 degrees. Exemplary measurements, are given below for a sleeve configured to form a hole through an 8 inch concrete slab. A height  208  of tapered portion  106  can be 8 inches. A radius  210  of cylindrical portion  108  can be 1 inch and a radius  212  at a top end of sleeve body  106  can be 1.5 inches. Finally a height  214  of base portion  108  can be 0.75 inches. However, this height can vary between 0.5 and 1 inches. For example, in some embodiments, height  214  can be 22/32 inches to match an actual thickness of a sheet of plywood being used to create a concrete form. 
       FIG. 3A  shows a cross-sectional view of reusable sleeve  100  installed on a wall  302  of a concrete form. Wall  302  can take the form of a sheet of plywood with a hole drilled through it to accommodate sleeve body  106 . A patch  304  can be affixed to wall  302  to cover the hole drilled through wall  302 . In some embodiments, patch  304  can be secured to wall  302  by fasteners  306 . In some embodiments, fasteners  306  can take the form of a nail or dry wall screw. In this way a recessed opening is formed that accommodates base portion  108  of sleeve body  102 . Attachment mechanism  104  is shown extending through channel  202  of sleeve body  102  and an opening in patch  304 . Attachment mechanism  104  is made up of bolt  308 , a first nut  310  and a second nut  312 . First nut  310  is configured to secure bolt  308  within channel  202  and prevent unwanted rotation of bolt  308  within channel  202 . Second nut  312  is used to secure attachment mechanism  104  to wall  302  and patch  304 . 
       FIG. 3B  shows how concrete  314  can fill in and conform around tapered portion  106  of sleeve body  102 . In some embodiments, bolt  308  can be configured to stabilize and improve the strength of sleeve  100  during a slab formation process. Sleeve body  106  is sized so that a top level of concrete  314  comes right up to a top surface of sleeve body  106 . This prevents a top portion of sleeve  106  from interfering with any smoothing operations applied to a top surface of concrete  314 .  FIG. 3C  shows how first nut  312  and then patch  304  can be removed from wall  302  after concrete  314  is finished at least partially setting. A force can then be applied to a threaded end of bolt  308  and/or base portion  108  of sleeve body  102  to dislodge sleeve  100  from concrete  314 .  FIG. 3D  shows how removal of sleeve  100  leaves a tapered hole  316  extending through both concrete  314  and wall  302 . Tapered hole  316  allows for a surveying tool to be shined through tapered opening  316  to align and register relative positions between various floors of a multi-story building. Inlet  318  can have a diameter of about 2 inches to allow for the accommodation of slight inaccuracies in the positioning of sleeve  100  on each floor.  FIG. 3E  shows how a tapered plug  320  can be lowered into channel  316 . A base of tapered plug  320  can have a diameter of about 2 inches to match the diameter of inlet  318 , thereby allowing tapered plug  320  to reach the base of concrete  314 . The sloped walls of tapered plug  320  match a taper of channel  316  allowing tapered plug to remain securely in place while channel  316  is filled in with additional concrete  322  as shown in  FIG. 3F . In some embodiments, a base of tapered plug  320  can be removed subsequent to additional concrete  322  finishing setting. In this way, tapered channel  316  can be used to facilitate alignment of the different floors of the building and then filled back up with additional concrete  322  so that there is little to no effect on a resultant strength of the concrete slab. 
       FIG. 4A  shows an alternative embodiment in which, a sleeve body  402  encloses a head and an upper portion of a bolt  404 . In some embodiments, bolt  404  can be partially insert molded within sleeve body  402 . In this way, bolt  404  need only extend through a lower portion of sleeve body  402 . Flattened surfaces of the head of bolt  404  can prevent bolt  404  from rotating within sleeve body  402 . As described before, nut  312  can be used to secure sleeve body  402  to wall  302 . Sleeve  402  is also shown including a removal feature  406  taking the form of a handle inset into a top portion of sleeve body  402  that assists in removal of sleeve  400 . In this way, removal feature  406  can be incorporated into the top of sleeve body  402  without interfering with a concrete smoothing operation. Removal feature  406  makes removal of sleeve  400  easier and in certain cases may allow for removal of sleeve  400  to be performed by one person instead of two. Removal feature  406  can take other forms including that of a simple loop to which a tool can be attached to assist in the removal of sleeve  400  from a formed concrete slab. 
       FIG. 4B  shows another alternative embodiment in which sleeve body  402  includes a second attachment feature  408  disposed at a top end of sleeve body  402 . Attachment feature  408  allows extensions to be added to the top end of sleeve body  402 . In particular, extensions  410  and  412  are suitable for attachment to attachment feature  408  and are depicted adjacent to sleeve body  402 . Attachment feature  408  can take many forms including a recess sized to facilitate alignment between extension blocks  410  and  412 . Extension blocks  410  and  412  can have cylindrical geometries and include cylindrical protrusions  414  that allows extension blocks to engage and stack atop sleeve body  402 . In some embodiments, protrusions  414  can include threading configured to engage threading arranged within attachment feature  408 . In some embodiments, each of extension blocks  410  and  412  can be configured to add a height of about two inches to sleeve body  402  to handle different thicknesses of concrete slabs; however, a height of extension blocks  410  and  412  can be varied or customized for unusual or custom applications. Extension block  410  is shown including its own attachment feature  416  (e.g., similar to attachment feature  408 ) to allow extension  412  to stack atop extension  410 . 
       FIG. 5  shows a perspective view of a one-time use sleeve  500  suitable for forming a hole in a concrete slab. One-time use sleeves may in some cases provide additional convenience (and cost savings) over reusable sleeves in that they do not require additional labor involved with removing the sleeve prior to filling the hole with concrete at the end of the alignment process. For example, at the end of the alignment process, such one-time use sleeves may simply be broken apart and discarded. The one-time use sleeves may also in some embodiments be constructed of cheaper materials than reusable sleeves, since the one-time use sleeves only need to perform their task for a relatively short duration as compared to reusable sleeves. In some embodiments, sleeve  500  may be made of a material that is structurally sound so as to withstand pressures as necessary, but also sufficiently brittle or otherwise conducive to breaking so as to allow for easy removal of the sleeve after concrete hardens or partially hardens around sleeve  500 . For example, sleeve  500  may be made of a plastic or polymer material such as high density polyethylene (HDPE). Sleeve  500  is hollow in order to reduce a weight and amount of material needed to form sleeve  500 . Making sleeve  500  hollow also reduces the amount of time needed to destructively remove sleeve  500  from a concrete slab after formation of the slab is at least partially complete. Sleeve  500  includes attachment flange  502  and sleeve body  504 . Sleeve body  504  may be tapered as illustrated in  FIG. 5 . As illustrated in  FIG. 5 , sleeve body  504  has a top end and a bottom end extending along a longitudinal axis. As illustrated in  FIG. 5 , attachment flange  502  of sleeve  500  may be attached to the bottom end of sleeve body  504 . Attachment flange  502  may extend laterally outward from the bottom end with respect to the longitudinal axis of sleeve body  504  (e.g., along a plane perpendicular to the longitudinal axis). The attachment flange  502  can include one or more fastening mechanisms for securely coupling sleeve  500  to, for example, a wall of a concrete form. For example, the attachment flange may include fastener openings, each configured to receive a screw, a nail, or a bolt for securely coupling sleeve  500  to a wall of a concrete form. Walls forming sleeve body  504  can be reinforced by structural ribs  506 . Structural ribs help to prevent the walls forming sleeve body  504  from undergoing deformation while a concrete slab sets around sleeve  500 . Structural ribs  506  allow the walls forming sleeve body  504  to be thinner or formed from a less rigid material than they otherwise could be without structural ribs  506 . While three ribs are shown and a fourth rib implied, it should be appreciated that a larger or smaller number of ribs are possible and within the contemplation of the invention. It should also be appreciated that structural ribs can also be formed within hollow sleeve body  504 . A number and/or disposition of the ribs can vary, but in some embodiments an X or star shaped rib configuration can be used to increase the rigidity of the walls forming sleeve body  504 . In some embodiments, structural ribs formed within sleeve body  504  can be configured to provide support for one or more extensions configured to increase a height of sleeve  500 . 
       FIG. 6A  shows a perspective view of another one-time use sleeve  600 . Sleeve  600  may be identical to sleeve  500 , except that sleeve  600  does not include any structural ribs such as structural ribs  506  in sleeve  500 . Sleeve  600  includes an attachment flange  602  and a sleeve body  604 , which may be tapered as illustrated in  FIG. 6 . Sleeve body  604  defines an internal volume  606  configured to reduce the amount of material needed to form sleeve  600 . As with sleeve  500 , the attachment flange  602  may be attached to the bottom end of sleeve body  604  that extends laterally outward from the bottom end with respect to the longitudinal axis along which the top and bottom ends of the sleeve body extend. As illustrated in  FIG. 6 , sleeve body  604  has a top end and a bottom end extending along a longitudinal axis. Attachment flange  602  of sleeve  600  may be attached to the bottom end of sleeve body  604 . Attachment flange  602  may extend laterally outward from the bottom end with respect to the longitudinal axis of sleeve body  604 , and can include one or more fastening mechanisms for securely coupling sleeve  600  to a wall of a concrete form. For example, the attachment flange may include fastener openings  608 , each configured to receive a fastener such as a screw, a nail, or a bolt for affixing sleeve  600  to a wall of a concrete form. In some embodiments, sleeve  600  can be formed of sheet metal or other robust material so that the walls of cylindrical portion  604  are able to withstand pressures exerted by the concrete slab as the concrete slab hardens around sleeve  600 . In some embodiments, similar to sleeve  500 , sleeve  600  may be made of a material (e.g., a plastic such as HDPE) that is structurally sound so as to withstand pressures as necessary, but also sufficiently brittle or otherwise conducive to breaking so as to allow for easy removal of the sleeve after the concrete hardens around sleeve  600 . In some embodiments, an opening leading into the interior of sleeve  600  can be closed by a cap that prevents stray concrete from entering sleeve  600  and making it harder to remove. In some embodiments, the cap can be removable while in other embodiments, the cap can be removed by cutting it away or otherwise disconnecting it from sleeve  600 . 
       FIG. 6B  shows cross-section schematics of different example embodiments of the sleeve in  FIG. 6A . The example sleeve  610  has a height of about 1 foot (about 30.48 cm), with a top diameter of the tapered portion of about 3 inches (about 7.62 cm), a bottom diameter of the tapered portion of about 1¾ inches (about 4.45 cm), and an outer diameter of the base portion of about 4 inches (about 10.16 cm). The example sleeve  620  has a height of about 10 inches (about 25.4 cm), with a top diameter of the tapered portion of about 2 13/16 inches (about 7.14 cm), a bottom diameter of the tapered portion of about 1¾ inches (about 4.445 cm), and an outer diameter of the base portion of about 4 inches (about 10.16 cm). The example sleeve  630  has a height of about 8 inches (about 20.32 cm), with a top diameter of the tapered portion of about 2 9/16 inches (about 6.51 cm), a bottom diameter of the tapered portion of about 1¾ inches (about 4.445 cm), and an outer diameter of the base portion of about 4 inches (about 10.16 cm). 
       FIGS. 7A-7D  show a series of illustrations demonstrating a use case for the sleeves described herein. Sleeve  100  is depicted for exemplary purposes only and it should be appreciated that any of the described sleeves could be used.  FIG. 7A  shows a concrete form  702  formed from multiple sheets of plywood. Metal rebar  704  is arranged within concrete form  702  to add strength to a resulting concrete slab. One or more holes  706  are formed in a base sheet  708  of concrete form  702  and sized to accommodate base portions of sleeves. For example, a hole  706  may correspond to the opening formed in wall  302  and as shown in  FIG. 3 . As another example, referencing  FIGS. 6A-6B , hole  706  may be sized to mate with the bottom diameter of the tapered portion of sleeve  600 . In this example, at least a portion of the attachment flange of sleeve  600  would extend around the hole, and may be fastened by fasteners (e.g., screws or nails) to base sheet  708 . 
       FIG. 7B  shows four sleeves  100  affixed to base sheet  708  near the corners of concrete form  702 . It should be appreciated that while a rather modestly sized concrete form  702  is shown that the described invention also scales and much larger concrete slabs are contemplated and within the scope of the inventive concept. For example, the described embodiments have been tested and used with a concrete slab having dimensions of 200 ft×120 ft (or about 60.96 m×36.58 m). 
       FIG. 7C  shows how concrete form  702  can be gradually filled with concrete  710 . While an amount of concrete  710  added to concrete form  702  is typically predetermined, sleeves  100  can provide an indication of the amount of progress being made in filling concrete form  702 . In some embodiments, sleeves  100  can include measurement indicators along the side or the tapered portion of the sleeve body allowing, for example, a better indication of how close to full the concrete form is. 
     As shown in  FIG. 7D , in some embodiments, sleeves  100  can be an excellent way of confirming a flatness of the resulting concrete slab since sleeves  100  can be the same height as the resulting concrete slab (or alternatively, measurement indicators on sleeves  100  can be checked to make sure that the concrete heights at the different locations corresponding to the sleeves are all equal or approximately equal). This flat upper surface and matching height prevents sleeves  100  from interfering in finishing operations that smooth an upper surface of the concrete slab prior to setting. After concrete  710  has hardened (or partially hardened), sleeves  100  may be removed from concrete  710 . An example method of removing an embodiment of a reusable sleeve is illustrated in  FIGS. 3C-3D . As for one-time use sleeves such as sleeves  500  and  600  in  FIGS. 5 and 6A , these sleeves may be broken and removed.  FIG. 7E  shows tapered channels  316  left behind after removing sleeves  100  from concrete  710 . 
       FIG. 7F  shows how an optical beam source such as a laser  752  can be positioned on a base floor atop a concrete slab  710 - 1  of a building  750 . A position of laser  752  can be chosen to coincide with a blueprint datum or other identifiable feature of building  752 . A location of each of tapered channels  316  can be identified by shining the laser onto a base of a concrete form associated with each of concrete slabs  710 - 1  to  710 - 4 . For example, once tapered channel  316 - 1  is formed, laser  752  can shine through tapered channel  316 - 1  to mark a position for tapered channel  316 - 2 . Prior to filling up each of tapered channels  316 , as described above, an at least partially translucent laser target that covers the opening can be positioned immediately above each of tapered channels  316 . An outline of the laser target can be scribed around the tapered opening so that once tapered opening is filled, a precise location defined by a laser beam  754  emitted by laser  752  can be marked on each of concrete slabs  710  so that inaccuracies due to any minor misalignment of tapered channels  316  can be ameliorated. In this way, builders can have a consistent reference point from floor to floor so as to avoid any drift or skewing of datums between floors. It should be noted that tapered channels  316  can be formed in each corner of slabs  710  or in a different pattern or number depending upon a geometry or other design features of a building  750 . Furthermore, in some large buildings multiple slabs could be positioned adjacent to one another on each floor. In such a configuration, each adjacent slab would include its own tapered channels  316 . 
     The various sleeve bodies illustrated and described in this disclosure extend along a longitudinal axis between a top end and a bottom end. A sleeve body may be constructed to have an inverted taper such that the top end of the sleeve body is wider than the bottom end of the sleeve body. For example, a cross-section of the top end (taken perpendicular to the longitudinal axis) may be greater than a cross-section of the bottom end (again taken perpendicular to the longitudinal axis). An inverted taper is advantageous in that it facilitates easy removal of the sleeve from a point above the concrete slab. For example, with a reusable sleeve, the sleeve can be slid upward out of the tapered channel that may be left behind. This would not be possible with a conventional tapered sleeve that is tapered in a non-inverted manner (i.e., with the bottom end being wider than the top end), because concrete hardening around the top portion of the sleeve would prevent such removal. The removal is similarly simplified with a one-time sleeve, because even if the one-time sleeve can be broken, the inverted taper provides easier access for breaking and removal of the pieces of the sleeve. Sleeves with inverted tapers are also advantageous in that they leave behind inverted tapered channels that facilitate insertion of plugs from a point above the concrete slab. That is, as illustrated in  FIGS. 3E-3F  and as described above in the associated text, a suitable dimensioned plug (e.g., a plug with a substantially matching inverted taper) similar to plug  320  may be lowered into the tapered channel until it is naturally secured in place due to its dimensions. Such easy insertion of the plug would not be possible with a taper created by a conventional, non-inverted sleeve. 
       FIG. 8  illustrates an example method  800  for aligning concrete slabs of a building structure. The method may include, at step  810 , positioning an optical beam source (e.g., a laser, an infrared source) on a first floor of a building structure. At step  820 , the method may include causing the optical beam source to emit an optical beam (e.g., a laser beam, an infrared beam) toward a first location of a concrete form of a second floor. At step  830 , the method may include forming an opening in the concrete form of the second floor at the first location. At step  840 , the method may include disposing a first sleeve at the first location. The first sleeve may include a sleeve body having a top end and a bottom end extending along a longitudinal axis, wherein the top end is wider than the bottom end; and an attachment flange attached to the bottom end of the sleeve body, wherein the attachment flange extends laterally outward from the bottom end with respect to the longitudinal axis, the attachment flange being configured to facilitate attachment of the sleeve body to a concrete form. At step  850 , the method may include securing the first sleeve to the concrete form of the second floor at the first location (e.g., by inserting one or more screws, nails, bolts, or other fasteners into one or more fastener openings of the attachment flange). At step  860 , the method may include pouring a first concrete mixture into the concrete form. At step  870 , the method may include allowing the first concrete mixture to at least partially harden around the first sleeve. At step  880 , the method may include removing the first sleeve so as to leave behind a first tapered channel in the first concrete mixture. 
     In some embodiments, the method may further include orienting the optical beam such that the optical beam is perpendicular to the first floor, and confirming that the optical beam travels through the first tapered channel such that the optical beam is perpendicular to the second floor. In some embodiments, the method may further include causing the optical beam to travel through the first tapered channel toward a second location of a concrete form of a third floor; forming an opening in the concrete form of the third floor at the second location; and securing a second sleeve to the concrete form of the third floor at the second location. The method may further include removing the second sleeve so as to leave behind a second tapered channel; and confirming that the optical beam travels through the first tapered channel and the second tapered channel. 
     In some embodiments, the method may further include positioning, through the first tapered channel, a tapered plug dimensioned to fit at a bottom of the first tapered channel; and pouring a second concrete mixture into the first tapered channel. 
     In embodiments where the sleeve is a one-time use sleeve, removing the first sleeve may include breaking the sleeve body and/or the attachment flange. In embodiments where the sleeve is reusable, the sleeve may be removed without breaking the sleeve body (e.g., by removing the fasteners from the fastener openings of the attachment flange and pulling out the sleeve body from the concrete). 
     Although this disclosure describes and illustrates particular steps of the method for aligning concrete slabs of a building structure as occurring in a particular order, this disclosure contemplates any suitable steps of such a method occurring in any suitable order. Moreover, although this disclosure describes and illustrates an example method for aligning concrete slabs of a building structure, including the particular steps illustrated in, for example, the method of  FIG. 8 , this disclosure contemplates any suitable method for aligning concrete slabs of a building structure, including any suitable steps, which may include all, some, or none of the steps of the method of  FIG. 8 , where appropriate. Furthermore, although this disclosure describes and illustrates particular components, devices, or systems carrying out particular steps of methods (e.g., the steps illustrated in  FIG. 8 ) for aligning concrete slabs of a building structure, this disclosure contemplates any suitable combination of any suitable components, devices, or systems carrying out any suitable steps of such method. Finally, although the disclosure focuses on aligning concrete slabs, the disclosure contemplates aligning any other suitable construction unit composed of any suitable mixture that is capable of being poured and hardened around a sleeve. 
     The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments, and particularly the surveying equipment, can also be embodied as computer readable code on a computer readable medium for controlling the measurement operations described herein. The computer readable medium is any data storage device that can store data, which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the described embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.