Patent Application
20250214211
The present invention relates to tools and, more particularly, to tools for installing collated rebar clips used for tying rebars together.
Concrete is a composite material made of fine and coarse aggregate bonded together with a fluid cement. After being poured and over time, it hardens and cures into a stone like substance.
Concrete is a convenient material used to construct roads, buildings, and other manmade structures. It is very strong in compression, but it is weak in tension as the concrete holding the aggregate together can crack allowing the structure to fail. To prevent this, steel reinforcing bars, or rebar, is placed within the concrete during construction to add tensile strength and increase the tensile load that can be carried. Rebar is supplied as long, thick wires or rods and is usually arranged horizontally or vertically in a grid or matrix pattern to form a flat mat or curtain, or in a three dimensional cage. Before concrete is poured over the rebar to encase it, the lengths of transversely intersecting rebar are joined together by short lengths of thin steel wire that is wrapped around the joints to tie or bind the rebar fixedly together preventing their relative movement. This is typically done manually and is a costly, time consuming, labor intensive, and backbreaking operation. It requires a worker to carry a wire reel or a supply of short wires and to constantly bend over while twisting the wires around the rebar with pliers or some other tool.
While tools have been developed to automatically apply and twist wire to tie rebar together, these tools are relatively complicated and require electrical power or compressed air to operate. At many construction sites, these power sources are not readily available, or when available, subject to intermittent supply.
Molded plastic clips have been developed in attempt to eliminate some of these issues. This type of clip can be snapped over adjoining rebars to lock them together. While automatic install tools can be used to install these clips, they still require a power source. In addition, these clips are available in relatively short lengths because the clips are molded as a integral piece so that they are connected together by the same material that makes up the clips. The frequent reloading of the install tool with short strips of clips results in a large amount of unproductive time that might otherwise be devoted to more productive labors.
The present invention is directed to overcoming one or more of the problems as set forth above.
It is an objective of the present invention to provide a tool that is cost effective during construction of rebar grids by enabling clips to be applied to rebars quickly and efficiently.
It is an objective of the present invention to provide a manually operated tool that does not require an outside power source, such as electricity, batteries, or compressed air.
It is an objective of the present invention to provide a tool that is capable of holding a large number of clips enabling long operating times between clip reloads.
It is an objective of the present invention to provide a tool that can be loaded with a flexible string of clips that can be easily separated from one another as they are used.
It is an objective of the present invention to provide a manually operated tool having large mechanical advantage enabling the tool to be operated easily with minimal exertion by a user.
It is an objective of the present invention to provide a tool of simple design that can be manufactured, maintained, or repaired quickly and inexpensively.
In an exemplary embodiment, a tool for applying rebar tying clips includes a hub assembly, a pair of grippable handles pivotally mounted to the hub assembly, and a magazine for holding a long string of clips.
In an exemplary embodiment, a tool for applying rebar tying clips includes a driver to forcefully move clips from a dispensing position within the hub assembly to an installed position on rebar during one operation of the handles and a feeder for moving clips from the magazine to the dispensing position during another operation of the handles.
In an exemplary embodiment, the handles are pivotally mounted in the hub assembly and are connected to the driver by links so that rotational motion of the handles between open and closed positions reciprocates the driver linearly within the hub assembly and substantial mechanical advantage is achieved.
In an exemplary embodiment, an anti-backup mechanism prevents clips from being moved from a preload position backward towards the magazine.
In an exemplary embodiment, the hub assembly has a pair of spaced side plates and a plurality of guide members spanning the space between the side plates with the guide members defining a first channel for linear movement of the driver and a second channel for passing clips from the magazine to a dispensing position to be engaged by the driver.
In an exemplary embodiment, the driver is movable from a retracted position above a clip in dispensing position downward to an extended position so as to install a clip on rebars and a throat is defined by arms of the side plates at the lower end of the driver channel and is adapted to receive two orthogonally placed rebars and support the rebars while the clip is pushed onto the rebars.
In an exemplary embodiment, guides are provided to align the rebars longitudinally and laterally in the tool so that the openings in the clips receiving the rebars are aligned with the rebars.
In an exemplary embodiment, the driver has a bottom drive surface for engaging the top of a clip in dispensing position and extending walls defining a pocket to hold such a clip in aligned position as the driver pushes the clip downward along the driver channel.
The details of construction and operation of the invention are more fully described with reference to the accompanying drawings which form a part hereof and in which like reference numerals refer to like parts throughout.
In the drawings:
All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood.
While the present invention is susceptible of embodiment in many different forms, there are shown in the drawings and will be described herein in detail a specific embodiment thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiment illustrated.
As seen in
In
As seen in
A plurality of rebar clips 25 are serially arranged in end to end relation as shown in
A pair of longitudinally extending grooves 36,37 are defined in the upper sides of the clip 25 with each of the grooves 36,37 having a dimension allowing the cords 34,35 to be placed within the respective grooves 36,37. Teeth, collectively designated 39, extend downward into each of the grooves 36,37 to engage and retain the respective cords 34,35 within their respective grooves 36,37 by pressing the cords 34,35 against the groove wall opposite the teeth 39.
Extending upward from the top of the each clip 25 are laterally extending raised ribs 40,41 at each longitudinal end that are separated by a laterally extending recess 42.
A long string of such collated clips can be loaded into the tool magazine 24. The magazine 24 acts as a chute to deliver the serially connected clips 25 to the hub assembly 21. As will be described hereafter, the clips 25 introduced from the magazine 24 will be detached from the end of the string and individually positioned and placed onto the rebars 26,27.
The tool 20 for placing a clip 25 on rebars 26,27 is best described by referring to
The tool handles 22,23 are pivotally connected to the hub assembly 21 and have inner portions 22a,23a that extend inwardly within the hub assembly 21 and outer portions 22b,23b that extend substantially upwardly away from the hub assembly 21. The outer portions 22b,23b are adapted to be gripped by a user 99 (
The hub assembly 21 comprises a body 45 and a reciprocatable driver 46. The body 45 includes a pair of parallel side plates 47,48 disposed in spaced relation on either side of a front plate guide 50, a rear blade guide 51, and a lower rebar guide 52. It is contemplated that the side plates 47,48 and the guide 52 be made of steel, while the driver 46 and the guides 50,51 be made of plastic. It is understood that other suitable materials may be employed as well. The internal surfaces of the side plates 47,48 and the guides 50,51,52 define a vertically extending driver channel and a horizontally extending clip channel.
The triangularly shaped front plate guide 50, which closes the front of the hub assembly 21, is fixed between forward portions of the side plates 47,48 by horizontally extending bolt 53a and cooperating nut 53b, and is held in operative orientation by upper and lower locating pins 53c,53d, respectively. The rear blade guide 51 is fixed between rearward portions of the side plates 47,48 by horizontally extending bolt 54a, cooperating nut 54b, and bushing 54c, and is held in operative orientation by locating pin 54d. The lower rebar guide 52 is fixed between lower portions of the side plates 47,48 by horizontally extending screws 55a,55b and is held in operative orientation by locating pin 55c.
As shown herein, the body 45 forms a driver channel 57 extending vertically and a clip channel 58 extending horizontally and intersecting the driver channel 57. The driver 46 is reciprocated vertically within the driver channel 57 and clips are moved horizontally along the clip channel 58 one at a time into the driver channel 57 under the driver 46.
The linear driver channel 57 has lateral faces defined by the flat inner surfaces 47a,48a of the respective side plates 47,48, a forward face defined by the rearward surface 50a of the front plate guide 50, an upper rearward face defined by the forward inner surface 51a of the blade guide 51, and a lower rear face defined by the forward inner surface 52a of the rebar guide 52. The upper and lower ends of the driver channel 57 are open.
The linear clip channel 58 has lateral faces defined by the inner surfaces 47a,48a of the side plates 47,48, an upper face defined by the bottom inner surface 51b of the blade guide 51, and a lower face defined by the upper surface 52b of the rebar guide 52. The inward end of the clip channel 58 is open and faces the rear surface 50a of the front plate guide 50. The outward end of the clip channel 58 is open to receive clips 25 presented from the magazine 24.
The side plates 47,48 each have large top portions mounting the clip driving components of the tool 20 and smaller lower portions for positioning and supporting rebar at the bottom of the tool 20. At the upper end of the top portion is a handle pivot 59, comprised of bolt 59a, cooperating nut 59b, and a bushing 59c that extends orthogonally between the side plates 47,48. The bushing 59c pivotally mounts the handles 22,23 between the side plates 47,48 for rotation about an axis orthogonal to the side plates 47,48 between an open position as shown in
The driver 46 has a rectangularly shaped cross section of a size and configuration similar to the driver channel 57 and reciprocates within the driver channel 57. A central slot 60 is defined located between lateral slots 60a,60b by lateral walls at the upper end of the driver 46. A driver pivot pin 61 extends through a horizontal bore 60c extending through the slots and extends laterally outward from either side of the driver 46 and is slidable within vertical slots 47b,48b formed in side plates 47,48, respectively.
Connecting links 62,63 extend between the inner portions of respective handles 22,23 and the driver 46. The links 62,63 are pivotally connected to respective handles 22,23 by upper pivot pins 62a,63a that extend laterally through holes in the inner ends of handles 22,23 and the top end of the links 62,63. The lower ends of the links 62,63 are disposed within respective lateral slots 60a,60b and are connected to the driver 46 by lower pivot pin 61 that extends through holes in the bottom ends of the links 62,63. The pivot pins are horizontally oriented such that the ends of the links 62,63 rotate about axes that are orthogonal to the side plates 47,48.
The arrangement of the handles 22,23, the links 62,63, and the driver 46 form a crank-link-slider mechanism that converts the rotational motion of the handles 22,23 into reciprocatable linear motion of the driver 46. Since the input distance between the handle pivot 59 and the outermost end of the handles 22,23 is greater than the output distance from the link pivots 62a,63a to the handle pivot 59, substantial mechanical advantage is achieved. It is contemplated herein that the input distance be at least five times the output distance.
When the handles 22,23 are moved from an open position toward each other, the links 62,63 are closed, lengthening the distance between the handle inner ends and the links lower ends, thereby pushing the driver 46 from a retracted position downward in the driver channel 57 toward an extended position at the bottom of the tool 20 and obstructing the inward end of the clip channel 58 to prevent new clips for entering the driver channel 57 from the clip channel 58. Similarly, when the handles 22,23 are moved from a closed position away from each other, the links 62,63 are opened, shortening the distance between the handle inner ends and the links lower end, thereby pulling the driver 46 from an extended position upward in the driver channel 57 to a retracted position away from the bottom of the tool 20. In retracted position, the inward end of clip channel 58 is no longer obstructed by the driver 46.
The magazine 24 is configured with a chute, or channel 64, to hold a long string of connected clips 25 that are arranged longitudinally therein. The magazine 24 is joined to the hub assembly 21 by trunnion-type tabs that extend laterally outward at the lower end of the magazine 24 and are held within apertures 47c,48c formed in the side plates 47,48 adjacent the rear of the hub assembly 21. A bracket 65 extending between the magazine 24 and the bolt 59a at the exterior of the hub assembly 21 supports the magazine 24 in a generally upright position. The lower end of the magazine 24 is positioned between the spaced side plates 47,48 at the outward end of the clip channel 58 such that serially arranged clips can be introduced into the open outward end of the clip channel 58 and moved toward the driver channel 57. The magazine 24 shown herein is arcuately formed so that the magazine 24 extends away from the handles 22,23 and their swing path. It is understood that since the clip string is flexible, the magazine 24 may take any suitable shape, linear or nonlinear.
For purposes of illustration herein, three clips 25a,25b,25c are shown in
The bottom of the driver 46 forms a pocket 67 that is sized and adapted to generally conform to the external shape of the clips 25 and the rebars 26,27. The pocket 67 is defined by a bottom drive surface 67a, a front wall 67b, and a pair of lateral side walls 67c,67d. The drive surface 67a is substantially flat for contacting engagement with the top surface of a clip. The front wall 67b forms a U-shaped channel 67e closed at its upper end sized to receive a longitudinally extending rebar 26. The side walls 67c,67d have arcuate concave recesses 67f,67g at the rearward lower ends that extend partially to the drive face 67a and the front wall 67b, the recesses being sized to receive a laterally extending rebar 27. The external rear edges 67h,67i of the side walls 67c,67d extending from the recesses 67f,67g upward to the drive face 67a are beveled to provide camming guide locators to align a clip in laterally centered position within the pocket 67 as it is moved into dispensing position under the driver 46 from the magazine 24.
Note that while a clip when engaged by the driver 46 is laterally centered, the clip is longitudinally offset rearwardly from the front wall 67b of the driver 46. To deliver a force directly over the center of the clip when it is in engagement with the driver 46, the pin 61 at the top of the driver 46 is offset rearwardly from the longitudinal center of the driver 46. Thus, the driver pivot pin 61, which receives downward force from the links 62,63, is longitudinally centered over the pocket 67 offset rearwardly from the center of the driver channel 57.
The blade guide 51 has an internally facing forward surface 51a, a downwardly facing bottom surface 51b, and an outwardly facing rearward surface 51c. The internally facing surface 51a is parallel to and spaced from the rearward surface 50a of the front plate guide 50. The blade guide 51 acts as a mounting block for a feeder lever 70 and an anti-backup pawl 71. The blade guide bushing 54c pivotally mounts the angled feeder lever 70 to the blade guide 51.
The feeder lever 70 is partially disposed within a center slot 72, which is formed in the center of the top, rearward, and bottom sides of the blade guide 51. The feeder lever 70 has a forward arm 70a (shown partially in phantom in
A pin 73 extends horizontally through an aperture 73a in the forward arm 70a and is vertically movable in a closed-end slot 74 formed in the upper end of the blade guide 51. A pair of vertically oriented compression springs 75a,75b are disposed in spaced relation under the pin 73 within a pair of cylindrical portions spaced along the slot 74 to effect rotation of the forward arm 70a upwardly against the driver pivot pin 61 and rotation of the downward arm 70b inwardly into the blade guide 51 urging feeder pawl 78 into engagement with clip 25a in the clip channel 58.
At the lower end of the downward arm 70b, a pivot pin 77 disposed within an aperture 77a pivotally mounts the pivoting feeder pawl 78 that includes a torsion spring 79 carried by pin 79a. The feeder pawl 78 moves into and out of the lower end of the center slot 72. The torsion spring 79 acting between the end of the downward arm 70b and the feeder pawl 78 provides a resilient force biasing the forward end of the feeder pawl 78 downwardly away from the blade guide 51 into engagement with clips in the clip channel 58. Intermediate the forward arm 70a and the downward arm 70b of the feeder lever 70 and extending rearward from the feeder lever 70 is a finger 80 that by upward movement enables the manual release of the feeder pawl 78 from engagement with the clips.
Downwardly extending dividing walls (unnumbered) at the bottom of the blade guide 51 define mounting slots 82a,82b on either lateral side of the center slot 72. A pivot pin 83 inserted through bores 84 in the dividing walls pivotally mounts the anti-backup pawl 71 and a torsion spring 85 within mounting slot 82a. The torsion spring 85 acting between the blade guide 51 and the anti-backup pawl 71 provides a resilient force biasing the forward end of the anti-backup pawl 71 downwardly away from the blade guide 51 into the clip channel 58 and into engagement with a clip providing a catch to prevent clips from moving backward toward the magazine 24 while allowing clips to slide by toward the driver channel 57.
Each of the side plates 47,48 has a support arm 87,88, respectively, extending forwardly from its bottom portion. The laterally spaced support arms 87,88 are spaced below the top portion of the side plates 47,48 to form forward opening throat 89. Each arm of the throat 89 are bounded by a horizontal upper edge 89a, a vertical rear edge 89b, a horizontal lower edge 89c, and an arcuate forward edge 89d. As can be seen in
The bottom face of rebar guide 32 defines a tapering longitudinal guide groove 90 that laterally locates the overlying longitudinal rebar 26 centrally under the clip being installed. The forward face 52a of blade guide 51 partially closes the back of the throat 89.
The operation of the tool 20 can now be described with reference to the above description and the attached drawings.
Referring to
The handles 22,23 are closed to push the driver 46 downward. As the overlying driver 46 advances, the clip 25a is pushed downward and the cords connecting it to the following clip 25b are severed. As the clip 25a is pushed further downward, the bottom of the overlying longitudinal rebar 26 is forced against the top of the underlying lateral rebar 27, which in turn is pushed against the support arms 87,88. The guide groove 90 of the rebar guide 52 centers the longitudinal rebar 26 between the side plates 47,48 and the longitudinal channel 67e of the driver 46 aligns the longitudinal U-shaped channel 30 of the clip 25a with the longitudinal rebar 26.
Closure of the handles 22,23 moves the driver 46 downward forcing the clip 25a over the longitudinal rebar 26 and onto the lateral rebar 27. The longitudinal rebar 26 is held in laterally aligned position by the guide groove 90 and the driver channel 67e. The lateral rebar 27 is held in longitudinally aligned position between the rear edge 89b of the throat 89 and the forward edges of the driver recesses 67f,67h. With the rebars 26,27 located in the throat 89 as the driver 46 is moved to fully extended position, the lateral rebar 27 is locked into the lateral channel 31 of the clip 25a and the longitudinal rebar 26 is locked in the longitudinal channel 30 of the clip 25a resulting in the two rebars 26,27 being tied together.
After the clip has been installed, the handles 22,23 are moved toward an open position lifting the driver 46. When the handles 22,23 are in their fully opened position, the compression springs 75a,75b acting against pin 73 in the forward arm 70a rotate the feeder level 70 to move the feeder pawl 78 downward and inward causing the forward edge of the feeder pawl 78 to engage the raised rib 40 of the next clip 25b and push it from preload position into dispensing position under the driver 46 thereby advancing the entire string of clips 25 held in the magazine 24. The anti-backup pawl 71 engages the forward rib of the clip in preload position to prevent movement of the clip string backward into the magazine 24.
At this point, the tool 20 can be moved to the next pair of rebars to be joined and the installation process is repeated.
While three clips 25 are shown for purposes of illustration herein, it is understood that much longer strings of clips are contemplated and are desirable. When long lengths of rebar clips 25 can be loaded into a tool magazine 24, the number of times the magazine has to be reloaded can be reduced saving time and effort. In addition, the use of a manually operated tool 20 without the necessity of providing a connection to electricity or pressurized air decreases costs and increases worker productivity.
It is understood that a long string of rebar clips as disclosed herein may contain hundreds of clips and may be arranged in a traverse coil and loaded into any suitably configured magazine.
From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention.
It will also be observed that the various elements of the invention may be in any number of combinations, and that all of the combinations are not enumerated here. It will be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. While specific embodiments of the invention have been disclosed, one of ordinary skill in the art will recognize that one can modify the materials, dimensions and particulars of the embodiments without straying from the inventive concept.
Other aspects, objects and advantages of this invention can be obtained from a study of the drawings and the foregoing disclosure.
Note that the terms “longitudinal,” “lateral,” “horizontal,” and “vertical.” as used herein are employed only to facilitate describing elements of the tool, the rebar, and the clip and their arrangement and do not denote any particular direction or limitation.
It should be understood that the terms “top,” “bottom,” “upper,” “lower,” “forward,” “rearward,” “downward,” “upward,” “inward,” “outward,” “inner,” “outer,” “end,” “front,” “back,” “side,” “first,” “second,” and similar terms as used herein, have reference only to the structure shown in the drawings and are utilized only to facilitate describing the invention. The terms and expressions employed herein have been used as terms of description and not of limitation.
As used herein, the term “adjoin” shall mean “to be close to or in contact with”; the term “within” shall mean “to be partially or completely inside of”; the term “axial” refers to a direction that is substantially straight; the term “transverse” refers to a direction other than the axial direction (e.g., orthogonal or nonorthogonal); the term “longitudinal” refers to a direction running generally lengthwise, e.g., from front to back; and, the term “lateral” refers to a direction running generally side to side.
