US2816342A - Form clamps - Google Patents

Description

R. W. HYRE Dec. 17, 1957 FORM CLAMPS Filed Dec. l, 1952 ATTORNEY United States Patent "Oiice 36,342 Patented Dec. 17, 1957 FORM CLAMPS Robert Warren Hyre, Chattanooga, Tenn.

Application December 1, 1952, Serial No. 323,433

3 Claims. (Cl. 24-269) This invention relates to improvements in form clamps, and more particularly to an improved clamp for holding together the separable parts of a form of a type used in the erection of concrete columns.

According to known erection methods, the lloor slabs, joints, girders, etc. of concrete structures are supported on concrete columns which are molded in situ in forms made up of separable parts `which are secured together by so-called form clamps serving to prevent the separable mold parts from spreading under the load of the wet concrete during pouring thereofand throughout its setting period. As such clamps are applied at intervals of one to two feet of vertical height of the forms, and remain in service during the setting period of the concrete making up the columns, it will be appreciated that the number of form clamps required during the course of a building operation is substantial. Hence, it is desirable that the initial cost of the clamps be held to a minimum.

Another requisite of a practical form clamp -is that it can be applied to the form and removed therefrom when the form is to be dismantled with the minimumi'of time and labor and with relatively unskilled'labor. The conventional form clamp heretofore used failed to satisfy this requirement, since its usually sectional construction required the services of two or more workmen for' its proper application. Thus the labor entailed in setting up and dismantling the column forms of even a moderatesize construction project represented a substantial item of cost and as well gave rise to the likelihood of delays in areas of labor shortage.

Stated broadly, it is a main object of the present 1invention to provide a form clamp characterized by highly effective yet inexpensive construction and by a design such that it may be assembled for use, applied to, and removed from the column form for re-use, at a fraction ofthe labor costs previously required for such operations.

Another important object of the invention is the provision of a form clamp whose design and mode of operation are such as to facilitate its handling during installa-` tion and disassembly, with the result that it may be more quickly applied to and removed from theform thanprior form clamps serving similar function and hence speeds up the overall operation of assembling and dismantling the column forms. i Yet another object of the invention is lthe provisionfof a form clamp characterized by a construction enabling it to'be assembled, applied to Iand linally removed from the form, by the practice of a simple seriesof operations capable of being performed by a single unskilled workman.

A further detailed object of the invention isthe. provision of a form clamp whose design is sufficiently exible astoupermit its use both as a form clamp and :as a wall forrntiea a w -f.-.:' f' @Other objectsarid-ffeatures .of advantage of adorn: clampzofthisinvention will appear ,from the :following detailed,description` thereof, in `conjunctionfwithT the. ae'-: companying drawing, in which- Fig. 1 is a section taken through a column form, with a form clamp according to the invention applied thereto;

Fig. 2 is an enlarged side elevation, partly in section, illustrating the manner of engagement of the combined buckle and winch element and the hook element of the form clamp shown in Fig. l;

Fig. 3 is a plan view of the form clamp parts illustrated in Fig. 2;

Fig. 4 is a detail view of the attaching lug provided on the combined buckle and winch element, which illustrate the shaping of the rail slot formed therein; and

Fig, 5 illustrates the form clamp of the invention applied as a wall form tie.

Referring to the drawing, a form clamp according to the invention generally comprises an elongated flexible element 10, a combined buckle and winch element 11, and a hook element 12. By reference to Fig. l, the iiexible element 10 is secured adjacent its one end to the buckle and winch element 11 and adjacent its other end to the hook element 12, and is adapted in use to encircle a column form illustratively comprising the separable parts or sides designated 13, 13a, 14, 14a. Upon the ends of the flexible element being secured together by engagement of the aforesaid elements 11 and 1 2, and proper tension being applied thereto by operation of the winch mechanism, the clamp as a whole serves to hold said form parts together and against spreading under the weight of the wet concrete filling the form during the setting period thereof.V Preferably, the form parts 13- 14a are each provided with a batten 16 whose end corners are cut away or chamfered as at 17, thus to minimize outside cornering of the form in the region to which the clamp is applied. As is well understood, the flexible element 10 is placed against the outer surface of the battens, which thus protect the form parts 11S-14a from wear or being scored by the pressure of the ilexible element upon tensioning of the latter.

The exible element 10 preferably comprises a ilexible steel band or strap of suicient gauge as to provide the requisite strength but which at the same time is suiiiciently ilexible that it may be looped around suitable securing means therefor and coiled on itself during tension@ ing thereof.

Referring to Figs. `2 and 3, the combined winch and buckle element 11 illustratively comprises anlelongated box-shaped frame having substantially parallel side walls 20, 21 and end walls 22, 23, of which the end wall 23 is adapted to cooperate with the hook element 12, as will be explained later. Said frame also includes upright ears 24, 25 which project above the upper edges of the frame side walls 20, 21 adjacent the free or outer ends thereof, and said ears provide a bearing for a winch shaft 28 extending transversely between the side walls. A frame as aforesaid may be inexpensively manufactured from two lengths of strap stock, one length being bent to box-frame formation and its meeting ends secured as by welding, and the'other length bent to the form of a U-member dimensioned so as to lit the inner side space of the box frame. Said frame components are then assembled in right-angular relationship as illustrated, and with the free ends of the legs of the inner U-member being disposed upwardly so as to provide the ears 24, 25, and the cross part 26 of the said inner U-member extending between the lower edges of the side walls 20, 21 of the'outer U-member, which latter forms the main frame for the element. Upon welding of the frame components together, anextremely'istrong and durable frame construction results.

It will be observed that the cross part 26 of the inner U-member forms in effect a partial bottom wallfor the middlelengthiportion of the frame enclosure. Such is preferably supplemented by a cross strap 27 welded in place between the side walls 29, 21 of the frame, and intermediate said cross part 26 and the frame end wall 23, being slightly spaced from the former so as to provide a transverse slot 26a whose purpose will be explained later.

Preferably, the Winch shaft 2S is fashioned from a length of half-round stock which is bent on itself to provide an eye 29 disposed externally of the frame and closely adjacent parallel half-round shaft portions which extend through and have bearing in the frame ears 24, 25. Said half-round shaft portions are spaced as by shims or the like to form a slot 30 through which the end of the exible band 10 is adapted to be passed and thereafter wrapped around the shaft so as to secure itself thereto as the band is wound or coiled on itself. The extended end of the winch shaft opposite the eye 29 provides for the reception of a nut 31, which is affixed to the shaft as by welding following mounting of the latter in the frame ears 24, 2S. Thus, the eye 29 at one end of the shaft and thc nut 31 at the other end thereof prevent axial separation of the shaft from the element frame, following final assembly of said parts.

The winch shaft mounts a ratchet wheel 32 which is aixed to said shaft as by welding in the axial space between the shaft eye 29 and the adjacent shaft mounting ear 25. As best seen in Fig. 2, the element frame mounts a pivoted pawl 34 disposed in the plane of the ratchet wheel 32 and which is preferably of sheet metal construction bent to channel formation. As is well understood, the free or nose end of the pawl 34 is adapted, when engaged in the space between any two adjacent teeth of the ratchet wheel 32, to lock the latter against turning in one direction (clockwise-Fig. 2); but, by virtue of its pivoted mounting, the pawl may be raised to permit rot-ation of the ratchet Wheel in the opposite direction. To strengthen the sheet metal pawl 34 against collapse under the great force to which it is subjected when the ratchet wheel tends to turn in clockwise direction, a buttress member or lug 3S is affixed to the element frame in position such that it is straddled by the pawl when the latter assumes its ratchet-wheel locking position. The buttress member is provided with an upper edge having inclination corresponding to that of the crotch or under surface of the pawl in the locking position thereof and thus effectively reinforces the pawl from within, and at the same time provides a positive abutment which prevents turning of the pawl in counter-clockwise direction past its locking position.

As seen in Fig. 4, the aforesaid element frame is provided with an external lug or ear 36 which is pierced by a keyhole shaped opening 37 having an elongated slot 37a connected into and extending at right angles from the straight leg portion 37b of said keyhole opening, at a point below (as viewed in Fig. 4) its upper end. Said lug extends laterally from the bottom-edge plane of the frame and provides a means for hanging the combined winch `and buckle element 11 on a nail 38 driven into a batteri 16 of the column form, during application of the j clamp lthereto.

The aforesaid hook element 12 illustratively comprises a U-frame having side walls 40, 41 and a cross part 42 extending therebetween, the frame being arranged so that its cross part 42 is disposed towards the aforesaid winch and buckle element 11. Said frame may also be simply formed from a length of strap stock bent to the form of a U-member as previously described in connection with the U-member frame component 24-26 of the element 11. As earlier forecast, one end portion of the exible band 10 is adapted to be connected to the hook element, and such a connection may be provided by two cross bars 44, 45 which are secured' between the frame sides adjacent their free or outer ends, of which the upper cross bar 44 functions as a tension bar and the lower bar 45 functions as a locking bar. As seen in Fig. 2, said bars 44, 45 have half-round or some appropriate modified half-round section designed to spread the stress of the band over a relatively large area, and they are arranged with their flat surfaces in facing relation and slightly spaced from one another. Moreover, rather than being disposed in directly overlying relation, the upper or tension bar 44 is longitudinally offset from the lower or locking bar 45 by an amount such that the rear edge of the former only slightly overlies the forward edge of the latter, this arrangement in conjunction with the vertical spacing of said bars providing a small gap through which an end of the flexible band 10 may be threaded. Such securing means provides not only an exceedingly el'ective friction securement of the end of the flexible band 1G to the frame of the hook 12, but, also, it locates the terminal or bent-over end portion of the band on top of the body or running length portion thereof, as seen in Fig. 2, and it also permits said hook frame and band to be simply assembled preliminary to final securement of said band. Thus, the assembly operation merely entails passing the bent-over end of the band through the long frame opening extending between its cross part 42 and the adjacent halfround bar 44, and thereupon shifting said parts as required to pass the bent-over end of the band through the gap between the bars 44, 45. Final securement may now be simply achieved by turning the hook frame and band to their relative positions shown in Fig. 2, whereupon the end of the band is frictionally secured to the frame.

The aforesaid hook frame carries a bill 46 functioning much as the bill of a conventional hook. The bill 46 may be conveniently fashioned from a length of band stock of width equaling the interleg space of the hook frame to the form of a V-member having one leg 46a longer than the other leg 46b by an amount generally corresponding to the depth of the frame. Securement of the bill 46 to the hook frame is simply achieved by arranging the said parts so that the upper edge of the shorter leg 46h abuts the under edge of the cross part 42 of the hook frame, with the longer leg 46a of the bill extending into the space between the side walls 40, 41 of said frame. Said parts are thereupon welded together along contacting edges or surfaces, such giving an extremely durable connection between the hook frame and its bill, all as illustrated.

By further reference to Fig. 2, it will be seen that the hook bill 46 depends a substantial distance below the under edge of the hook frame, with the result that said frame normally assumes an inclined position when placed against a at surface such as a batten 16. Preferably, this distance is somewhat less than the depth of the cross part 23 of the aforesaid winch and buckle frame so that, when the elements are engaged as shown, the forward or hook end of the hook frame rests directly on the upper edge of said cross part 23. Such results in the hook frame, when so engaged, having greater than normal inclination, and also in the lower or pointed end of the hook bill 46 being spaced slightly from the batten surface. It is also to be noted that by design the angular relation which the leg 46a of the hook 46 bears to the under edge of the hook frame is.such that when the parts are properly engaged, as shown in Fig. 2, the engaging surfaces of the hook leg 46a and of the cross part 23 of the buckle frame have flush or surface contact, as distinguished from point or line contact, a feature which insures even distribution of the high separating forces applied to the elements 10 and 11 upon tensioning of the flexible band 10 throughout said contacting surfaces.

In applying a form clamp as described to the column form, the ends of the flexible band 10 are preliminarily secured to the combined which and buckle element 11 and the hook element 12, as previously described, and as seen in Fig. 2, with the band disposed to extend beneath the rearward end wall 22 of the frame of element 11 and the rear portion of the frame of the element 12, whereby it is adapted to be held down on the batten by said frame in the subsequentV `band-tensioning operation.

Thereupon, the combined winch and buckle element is applied to the form by hanging same on the nail 38 driven into one of the battens 16 in a prior operation, said element lowering due to its weight so that the nail shank enters the upper end of the straight-leg portion 37b of the keyhole opening 38. The flexible band is then pulled around the form and the bill 46 of the hook element 12 is thereupon engaged with the cross part or end 23 of the winch and buckle frame, said cross part thus functioning as a buckle.

The workman now proceeds to tighten the flexible band by rotating the winch shaft 28 in proper direction (counter-clockwise-Fig 2) either by a wrench applied to the shaft nut 31 or by a bar-type tool inserted through the shaft eye 29. Initially this tightening is carried on to the extent that the combined winch and buckle element tends to crawl or move leftwise (Fig. 3), which crawling movement if continued would cause the nail 38 to pull out of the batten. When such crawling is indicated, the workman simply taps said element with a suitable tool in direction as to cause it to move upwardly the small amount required to release the nail into the elongated slot 37a, whereupon said element may move horizontally to the left with respect to the nail, as the band is further tensioned as required. During the aforesaid tensioning operation, the pawl 34 is held in its raised position, but upon the requisite tension being applied the pawl is lowered against the buttress member 35, its nose end meanwhile engaging in a notch between two adjacent teeth of the ratchet wheel 32. The tendency of said wheel to turn in the opposite (clockwise) direction consequent to the tension etect of the exible band results in secure locking engagement of the ratchet wheel and pawl, which maintains the tension applied to the flexible band.

The ease with which a form clamp according to the invention may be installed and tensioned is notable, as is the fact that such requires the services of a single workman only. Thus, the combined winch and buckle element is supported from the form itself during application, and the inclination of the hook element 12 permits the workman to grasp the same from beneath, a feature which facilitates and makes easy the engagement of the hook 46 with the cross part 23 of the winch and buckle element. To disassemble the clamp, it is necessary only for the workman to grip the hook element 12 with one hand, the lingers of which may extend beneath the same due to its inclined position with respect to the batten surface, to apply a slight amount of further tension to the band as permits the pawl 34 to be disengaged from the ratchet wheel 32, and finally to lift the hook element away from the winch and buckle element. Thereupon, the clamp may be removed from the form simply by slipping the latter element off the batten nail 38.

In addition to serving the primary function as a form clamp, a clamp according to the invention may also be employed as a wall form tie. Such application is generally illustrated in Fig. 5, wherein a typical wall form is shown to comprise a pair of form walls 50, 50a made of suitable lumber horizontally disposed, external studding 52, 52a which is vertically disposed, and outer horizontally extending Walls 54, 54a. At the desired tie location, aligned holes are provided in the walls 50, 50a and wales 54, 54a, as shown.

In applying the aforesaid clamp as a tie, the tlexible band 10 is disconnected from the hook element 12 and its now free end is threaded through the aforesaid aligned holes, the combined winch and hook element (now functioning solely as a winch element) being meantime hung from a nail driven into one wale 54a. To permit this type of hang-on support, the aforesaid cross strap 27 of the winch frame is provided with a keyhole shaped opening 56 (Fig. 3) similar to the opening 37 of the lug 36 but disposed at right angles thereto so that the winch frame may be hung vertically. In this position, the exible band 10 adjacent its portion coiled on the winch shaft 28 may be passed through the aforesaid slot-like opening 26a provided between the frame cross part 26 and its cross strap 27 on a substantial line of tangency with respect to the winch shaft which extends through the frame bottom. Alternatively, the band 10 may be passed through a transverse slot 26b provided in the cross part 26 of the aforesaid U-member 24-26 of the main frame of the element 11 (see dotted line Fig. 2), and the pawl 34 locked in engagement with the ratchet 32 as by a pin (not shown) inserted into opening 57 therefor provided in the pawl and its -buttress plate 35.

The free end of the exible band is re-secured to the hook frame, and the latter is thereupon hung through its hook 46 from the wale 54, as shown. The winch shaft 28 may now be turned in proper direction as to tension the exible band 10 the desired amount as to tie the form walls 50, 50a together against the load of the concrete placed therebetween.

As many changes could be made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a form clamp, a flexible element adapted to extend about the form, interengaging buckle and hook elements operatively connected to the respective ends of the exible element, the buckle element comprising an elongated open top frame having parallel upright side walls, ears projecting upwardly from the side walls, a transversely extending winch shaft journaled in said ears, the shaft portion between said ears having means for securing one end of the exible element thereto, the ends of the shaft A projecting beyond said ears and carrying means for turning the shaft, a ratchet wheel aflixed to the shaft intermediate one of said means and the proximate ear, a pivoted pawl carried by the frame side wall proximate said ratchet wheel for locking said wheel and shaft against rotation in one direction, said pawl having channel section, and said frame side wall being provided with means extending into the pawl channel and serving to reinforce the pawl from within against forces transmitted thereto by the ratchet wheel.

2. In a form clamp, a exible element adapted to extend about the form, a combined winch and buckle element adapted to bear at against a form surface and being operatively connected to one end of said exible element, said winch and buckle element including an elongated open-top frame having a transversely extending upright end wall, a hook element operatively connected to the other end of the flexible element and including an elongated frame member having transversely spaced upright sides and means at one end for connecting the flexible element thereto and a hook member at, its other end adapted to interengage with the winch and buckle element, said connecting means and hook member extending transversely between the upright sides of the hook element, said hook member depending from the lower edge of the frame member and comprising a length of strap stock bent to the form of a V, the construction and arrangement being such that the hook member is adapted to project into the open top frame of the winch and buckle element, with one leg of said hook member engaging flush against the inner surface of the upright end wall of said open top frame, whereby to connect the ends of the flexible element and to dispose the hook frame member at an inclination to the form surface.

3. In a form clamp, a flexible element adapted to extend about the form, a combined winch and buckle element adapted to bear at against a form surface and being operatively connected to one end of said exible element, a hook element operatively connected to the other end of the flexible element and including an elongated frame member having transversely spaced upright sides and means at one end for connecting the ilexible element thereto and a hook member at its other end adapted to interengage with the winch and buckle element, -said connecting means and hook member extending transversely between the upright sides of the hook element, said 1100i; member depending from the lower edge of the frame member of said hook element, said hook element cooperating with said winch and buckle element in such a way as both to connect the ends of the exible element and to dispose the hook frame member at an inclination to the form surface, said winch and buckle element including a lug extending outwardly from the bottom edge line thereof, said lug having therein a key-hole shaped opening for receiving a nail by which said Winch and buckle element may be temporarily held at against said form surface and an elongated slot disposed. at a right angie to and connecting at one end with the vertical leg portion of said opening intermediate its ends, said slot permitting bodily movement of said-winch and buckle element with respect to the nail upon tensioning of the flexible element.

Y 4:References Cited in the le of this patent UNITED STATES PATENTS Carroll Nov. 2, 1886 Barnett Mar. 20, 1900 Hastings Jan. 3, 1905 Hodge et al. Apr. 11, 1905 Parisho June 29, 1915 Scharnberg Apr. 8, 1919 Tabler June 20, 1922 Bosco May 8, 1923 Lampert Sept. 11, 1923 Pasqualle July 5, 1927 Oishei et al. Oct. 30, 1934 Blagden Oct. 16, 1945 FOREIGN PATENTS Great Britain of 1899

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