Patent Application
20090242729
The present invention relates to apparatuses and ties for connecting forming panels used in casting cementitious or other material, such as concrete. More particularly, the present invention concerns a primary pin apparatus having an adjustable one-step connection and disconnection mechanism, a supplemental pin apparatus for supplementing the primary pin apparatus and engaging ties, and an improved tie having a non-circular engagement hole.
Formwork is used to contain and shape cementitious or other flowable material, such as concrete, during the pouring and setting, or curing, processes. One common use of formwork is in the casting of walls. Once the material has sufficiently set, the formwork is stripped, or struck, therefrom to be reused elsewhere.
Generally, formwork comprises parallel, spaced apart rows of forming panels, with each panel of a row being temporarily connected to an adjacent panel to define a side of the structure being cast. Various mechanisms have been used to accomplish the connection of adjacent forming panels, including complimentary nuts and bolts and complimentary pins and wedges. Unfortunately, these mechanisms generally suffer from a number of problems and disadvantages, including frequent loss of loose pieces and longer time and increased labor costs associated with engaging and disengaging the mechanisms in order to erect and strip the framework.
One such mechanism comprises a retractable pin and latch. When it is desired to connect adjacent panels, the retracted pin associated with a first panel is extended through a corresponding hole in the second panel. Often this is accomplished by striking the opposite end of the pin with a hammer to drive it through the at least partially aligned hole. The latch is then manually engaged to prevent the inadvertent retraction of the pin and disconnection of the panels. When it is desired to disconnect adjacent panels, the engaged latch is first manually disengaged, i.e., pried opened and pulled back to provide sufficient clearance, and then the pin is retracted, by striking the end of the pin with a hammer, from the corresponding hole. It will be appreciated that this process requires several steps, and, furthermore, that accomplishment of one or more of these steps may be hindered by the aforementioned transverse stress caused by the weight of the poured material pressing upon the panels.
Additionally, ties are used to extend between and connect the parallel rows of forming panels in order to maintain the desired spacing even under the transverse stress caused by the weight of the poured material. The tie presents a circular engagement hole through which the aforementioned pin is inserted. This hole in the material of the tie creates weak points of relatively thin material above and below the hole, i.e., between the edge of the hole and the edge of the tie, at which the tie is more susceptible to failure.
The present invention overcomes the above-discussed and other problems and disadvantages by providing a primary pin apparatus having an adjustable one-step connection and disconnection mechanism, a supplemental pin apparatus for supplementing the primary pin apparatus and engaging ties, and an improved tie having a non-circular engagement hole.
In one embodiment, the primary pin apparatus comprises an engagement pin including one or more locking fingers which selectively protrude angularly outward from a longitudinal axis of the engagement pin such that a first force applied to a rearward end of the pin assembly sets the locking fingers in a state of relatively greater protrusion which locks the adjacent panels together, and a second force applied to a forward end of the pin assembly releases the locking fingers to a state of relatively lesser protrusion which unlocks the adjacent panels.
In various implementations, the primary pin apparatus may include any one or more of the following additional features. The head end of the engagement pin may be tapered to facilitate disconnecting and separating the adjacent panels. The head end may be approximately between less than 1.625 inches and 0.5 inches long. The apparatus may further include a set/release pin which is slidably received within the engagement pin, wherein the engagement pin is placed in the locked position by the first force applied to a rearward end of the set/release pin which both drives the engagement pin through aligned openings in the adjacent panels and sets the locking fingers in the state of relatively greater protrusion to prevent withdrawal of the engagement pin from the openings, and the engagement pin is placed in the unlocked position by the second force applied to a forward end of the set/release pin which releases the locking fingers to the state of relatively lesser protrusion, and the engagement pin is placed in a retracted position by a third force applied to the forward end of the engagement pin. The apparatus may further include a lock button operable to selectively lock the engagement pin in the retracted position. The engagement pin may include one or more relief features which are engaged by the lock button, and wherein at least one of the relief features corresponds to the retracted position. The apparatus may further include a housing, a guide sleeve slidably received within the housing, wherein the engagement pin is received within the guide sleeve, and a biasing spring operable to exert a biasing force on the guide sleeve in the forward direction. The engagement pin may include an externally threaded region, and the guide sleeve may include an internally threaded region operable to engage and cooperate with the externally threaded region of the engagement pin such that rotating the guide sleeve relative to the engagement pin causes the engagement pin to correspondingly move in the forward or rearward directions relative to the guide sleeve.
In one embodiment, the supplemental pin apparatus may comprise an engagement pin including one or more locking fingers which selectively protrude angularly outwardly from a longitudinal axis of the engagement pin, and a set/release slidably received within the engagement pin and biased in a forward direction to normally place set the locking fingers in a state of relatively greater protrusion which locks the adjacent panels together, and, when pushed in a rearward direction, releases the locking fingers to a state of relatively lesser protrusion which unlocks the adjacent panels.
In various implementations, the supplemental pin apparatus may include any one or more of the following additional features. The head end of the engagement pin may be tapered to facilitate disconnecting the adjacent panels. The head end may be approximately between less than 1.625 inches and 0.5 inches long. The apparatus may further include a flange located on a rear portion of the engagement pin, wherein, when the apparatus is connecting the adjacent panels, the adjacent panels are located between the flange and the locking fingers. The apparatus may further include one or more O-rings located at least partially around the engagement pin to provide friction resistance for maintaining the apparatus fully within a receiving hole of at least one of the panels.
In one embodiment, the improved tie comprises a body which is elongated along a longitudinal axis and has an end presenting an engagement hole for receiving a pin operable to secure the tie to the first panel, with the engagement hole having a greater dimension along the longitudinal axis and a lesser dimension along an axis which is perpendicular to the longitudinal axis.
In various implementations, the improved tie may include any one or more of the following features. The engagement hole may be is non-circular. The engagement hole may have a first lobe and a second lobe. The first lobe and the second lobe may be the same size. The first lobe and the second lobe may be the same shape. The first lobe and the second lobe may have different sizes. The first lobe and the second lobe may have different shapes.
These and other features of the present invention are described in greater detail below in the section titled DETAILED DESCRIPTION.
The present invention is described herein with reference to the following drawing figures, with greater emphasis being placed on clarity rather than scale:
With reference to the drawing figures, a primary pin apparatus 10, a supplemental pin apparatus 110, and an improved tie 277 are is herein described, shown, and otherwise disclosed in accordance with one or more embodiments, including one or more preferred embodiments, of the present invention.
More particularly, the present invention concerns a primary pin apparatus 10 having an adjustable one-step connection and disconnection mechanism, a supplemental pin apparatus 110, also referred to as a “short pin”, for supplementing the primary pin apparatus 10 and engaging ties 177, and an improved tie 277 having a non-circular engagement hole.
Referring particularly to
More specifically, referring also to
Referring particularly to
The housing 20 of the pin mechanism 12 is operable to receive and cooperate with various other components of the pin mechanism 12 to facilitate the functions thereof, and to secure the pin mechanism 12 to the mounting structure 14. The housing 20 may include a receiver 40 and a mounting plate 42. The receiver 40 may be a substantially tubular, e.g., cylindrical, structure having a first opening 60 at a first end, a second opening 62 at a second end, and a third opening 64 in a sidewall near the second end. One or more of these openings 60,62,64 may be provided with a seal, e.g., an O-ring or other gasket, to aid in retaining a lubricant, e.g., oil or grease, within the receiver 40 which facilitates the movement of various components therein. The receiver 40 may further include a mounting flange 44 for coupling the receiver 40 with the mounting plate 42. The mounting plate 42 includes one or more coupling structures for coupling the housing 20 to the mounting box 14. For example, the coupling structures may be first and second flanges 66 which are slidably received within a corresponding sleeve structure 68 on the mounting box 14 (as shown in
The guide sleeve 22 is operable to cooperate with the engagement pin 30 in such a manner as to allow for adjusting the distance that the engagement pin 30 extends through the hole in the second panel B. The guide sleeve 22 may be substantially tubular, e.g., cylindrical, structure having a first opening 70 at a first end, a second opening at a second end 72, an internal threaded region, and an external flange 74. The guide sleeve 22 is slidably partially received within the housing 20 through the first opening 60 of the first end of the housing 20, with the second opening 72 of the second end of the guide sleeve 22 being located within the housing 20. The internal threaded region is located in an intermediate area between the first and second ends of the guide sleeve 22, and cooperates with an externally threaded region (described below) on the engagement pin 30. The external flange 74 surrounds an area at or near the first end of the guide sleeve 22 and facilitates turning the guide sleeve 22. The external flange 74 may be knurled or otherwise textured or contoured on an external surface to minimize slippage when turning the guide sleeve 22.
The biasing spring 24 is operable to bias the guide sleeve 22 and other components in a normally forward direction relative to the housing 20 and the mounting box 14. The biasing spring 24 includes a first end and a second end. The biasing spring 24 may be partially received within the guide sleeve 22 through the second opening 72 of the second end of the guide sleeve 22 (best seen in
The biasing spring 24 also provides the advantage of tightening the connection between the panels A,B as they move slightly as a result of, for example, wind, vibration, or workers walking on the tops of the panels A,B. More specifically, other mechanisms can loosen under such influences, but, to the extent the engagement pin 30 is not fully extended through the hole in the second panel B, the biasing spring 24 prevents the engagement pin 30 from working itself out of the hole and, furthermore, forces the engagement pin 30 deeper into the hole whenever possible. Additionally, if the spring-constant of the biasing spring 24 is sufficiently low, the pin assembly 26 can be moved from the locked to the unlocked positions by hand, i.e., by pushing the set/release pin 32, thereby avoiding the deleterious effects of frequent hammering.
The pin assembly 26 is operable to physically engage and disengage an adjacent forming panel, tie, or other structure. Referring particularly to
The engagement pin 30 is operable to slidably engage and disengage the second panel B. The engagement pin 30 may be substantially elongated and include a first opening 80 at a head end 82, a second opening 84 at a second end, an externally-threaded region 86, one or more relief features 88, and an internal channel extending between the first opening 80 and the second opening 84. The head end 82 may be tapered, e.g., substantially frustoconical, in shape and include one or more, e.g., approximately between two and four, locking fingers 90 which are outwardly protrudable from a surface of the head end 82. In order to facilitate clearing the head end 82 when rotating the forming panels A,B apart, as discussed below, the head end 82 may be, in various implementations, less than 1.625 inches, approximately between less than 1.625 inches and 1 inch, and approximately between less than 1.625 inches and 0.5 inches.
In one implementation, depending on the taper and length of the head end of the engagement pin 30, as well as the resistance provided by the locking fingers 90, the set/release pin 32 need not be pushed or struck to allow the forming panels A,B to be rotated apart.
The externally-threaded region 86 engages and cooperates with the internally-threaded region within the guide sleeve 22 to allow for selectively lengthening or shortening the reach of the engagement pin 30 relative to the second panel B by turning the guide sleeve 22 in the appropriate counterclockwise or clockwise direction, respectively. This adjustment feature advantageously allows for accommodating panels with differing dimensions as well as additional hardware which it may be desirable to secure to one or both of the panels A,B using the apparatus 10 of the present invention. This adjustment feature also allows for making the connection between panels A,B as tight or as loose as desired, and accommodates arranging the panels A,B in a curved or other non-parallel manner.
The relief features 88 allow for temporarily maintaining the engagement pin 30 in a particular position, which may be its fully extended position, its fully retracted position, or some intermediate position.
The set/release pin 32 is operable to set and release the one or more locking fingers 90 at the head end 82 of the engagement pin 30. The set/release pin 32 includes a first end 100 and a second end 102. The first end 100 may include a taper, or the functional equivalent thereof, and the second end 102 may include an externally-threaded region. The threaded region extends through the second opening 64 in the housing 40, and a cap 104 which is larger than the second opening 64 is threaded onto the second end 102 of the set/release pin 32 in order to define the maximum extension of the set/release pin 32 relative to the housing 40.
A second biasing spring 101 may be used to bias the set-release pin 32 in a normally forward, or extended, direction, thereby automatically and actively working to achieve and maintain a secure connection between the forming panels A,B. For example, if the engagement pin 30 is adjusted too short or if the forming panels A,B are not properly positioned relative to one another, such that the locking fingers 90 are located partially within the hole in panel B and therefore not fully extended, the biasing spring 101 acts to push the set/release pin 32 forward and thereby maintain outward pressure on the locking fingers 90 to achieve the best connection possible under the circumstances.
The set/release pin 32 is slidably received within the internal channel of the engagement pin 30. In a locked position, the first end 100 of the set/release pin 32 protrudes through the first opening 80 in the head end 82 of the engagement pin 30 and the taper of the first end 100 of the set/release pin 32 is positioned so as to set, or engage, the locking fingers 90. As mentioned, the cap 104 threaded onto the second end 102 of the set/release pin 32 is larger than the second opening 64 in the housing 20 and defines the maximum relative position of the set/release pin 32 in the locked position when the cap 104 engages the housing 20 surrounding the second opening 64.
The mounting box 14 supports the pin mechanism 12 in its operating positions, i.e., both its locked and unlocked positions. The mounting box 14 may include a five-sided box, i.e., four sidewalls and a bottom, and the receiver 68. The receiver 68 may be affixed to the bottom of the mounting box and slidably receives the flanges 66 of the mounting plate 42 of the housing 20 of the pin mechanism 12 (as shown in
The apparatus 10 may further include a lock button 110 operable to selectively lock the engagement pin 30 in a retracted position. The lock button 110 may include a spring-loaded shaft which extends through the third opening 62 in the sidewall of the housing 40 and cooperates with the one or more relief features 88 in the surface of the engagement pin 30. When the shaft engages a relief feature 88, the engagement pin 30 is locked in the corresponding position; when the lock button 110 is depressed, the shaft disengages from the relief feature 88. The shaft of the lock button 110 acts against a flat on the side of the engagement pin 30 to prevent rotation thereof, wherein such rotation might otherwise hamper or prevent the ability to rotate the forming panels A,B apart, as discussed below.
The lock button 110 may also function to maintain the engagement pin 30 and, more specifically, the locking fingers 90 associated therewith, in a particular orientation. If the engagement pin 30 rotates, the locking fingers 90 may become oriented in such a manner as to make separating the panels A,B more difficult, particularly under stress; thus, the lock button 110 prevents such rotation unless depressed.
In exemplary use and operation, the apparatus 10 of the present invention may be used and function substantially as follows. Referring again to
When it is desired to unlock the first and second forming panels A,B, the first end of the set/release pin 32 is struck to drive the set/release pin 32 rearwardly and release the locking fingers 90, a seen in
In one application, the pin mechanism 12 is provided by itself, i.e., separate from any mounting box 14, so that it can be used, as desired, to make spot connections at particular points on the panels A,B, such as at the bottom of the formwork where pressures due to the weight of the poured material are greatest.
Referring also to
Referring also to
Referring also to
The short pin 110 is a simplified, and therefore less expensive version of the primary pin apparatus 10. More specifically, the short pin 110 comprises an engagement pin 130; a set/release pin 132; locking fingers 190; a flange 175; and one or more O-rings 177. The engagement pin 130, set/release pin 132, locking fingers 190, and flange 175 may resemble and function substantially similar to the corresponding structures of the primary pin apparatus 10.
More specifically, the set/release pin 132 is slidably received within the engagement pin 130. A biasing spring 124 may be used to bias the set/release pin 132 in a normally forward, or extended, locking position in which locking fingers 190 are in a state of relatively greater protrusion. As with the primary pin apparatus 10, when the head of the set/release pin 132 is pushed or struck, the locking fingers 190 are released to a state of relatively lesser protrusion, which allows the forming panels A,B to be rotated apart (as seen in
In one implementation, depending on the taper and length of the head end of the engagement pin 130, as well as the resistance provided by the locking fingers 190, the set/release pin 132 need not be pushed or struck to allow the forming panels A,B to be rotated apart.
Because the short pin 110 is not necessarily secured to a mounting structure, the one or more O-rings 177 are located at least partially around the engagement pin 130 in order to provide resistance to maintain the short pin 110 in position on forming panel A, such as before the other forming panel B is coupled therewith or when the set/release pin 132 is pushed. The O-rings 177 may be of any suitable material, such as metal or synthetic materials, for providing the required resistance.
As mentioned, the relatively inexpensive and less complex short pin 110 may be used to supplement the primary pin apparatus 10 where needed, especially with regard to engaging ties 122. Additionally, the short pin 110 may be used to supplement other connection mechanisms, including prior art connection mechanisms such as pin-and-wedge and pin-and-latch mechanisms, and so has use apart from the apparatus 10.
Referring also to
The improved tie 277 comprises a body 278 which is elongated along a longitudinal axis and has an end presenting a hole 280 for receiving a pin 282 operable to secure the tie to the forming panel A, with the hole 280 having a greater dimension along the longitudinal axis and a lesser dimension along an axis which is perpendicular to the longitudinal axis. The non-circular hole 280 minimizes the aforementioned weakness by leaving significantly more material between the edge of the hole 280 and the edge of the tie 277.
In one implementation, the hole 280 is has two connected lobes 284,286. One lobe 284 may be larger than the other lobe 286, as seen in the figures, or the lobes may be of equal size. Additionally, the lobes, 284,286 may have the same or different shapes. The lobes 284,286 are oriented substantially on and along a longitudinal axis of the tie 277, such that the maximum dimension of the hole 280 along an axis which is perpendicular to the longitudinal axis of the tie 277 is less than the maximum dimension of a circular hole along the same axis, thereby leaving a greater thickness of material than is left by corresponding circular hole.
In one implementation, the hole 280 has a maximum dimension which is substantially equal to the prior art circular hole and is otherwise generally shaped such that an engagement pin having a cross-sectional shape matching the hole 280 will also fit closely within, and can therefore be used with, prior art ties having circular holes.
As mentioned, the cross-sectional shape of the head end 82 of the engagement pin 30 of the primary pin apparatus 10, or of the engagement pin 130 of the short pin 110, can be shaped so as to correspond to the shape of the hole 280 in the tie 277 so as to be receivable therethrough. In one implementation, such correspondence requires that one or more grooves 288 be provided in the surface of the head end 82 to accommodate the specific contours of the shape of the hole 280. Depending on where these grooves 288 are located in the surface of the head end 82, one or more of the locking fingers 92 may have to be resized or repositioned to accommodate the groove(s). As also mentioned, in one implementation the resulting cross-sectional shape of the head end 82 is such that the engagement pin 130 can still be used with prior art ties have circular holes.
The improved tie 277 may also be used with other connection mechanisms, including prior art connection mechanisms such as pin-and-wedge and pin-and-latch mechanisms, if the head ends of the pins are appropriately adapted as discussed, and so has use apart from the primary and supplemental pin apparatuses 10,110.
Although the invention has been disclosed with reference to various particular embodiments, versions, and implementations, it is understood that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims.
