AU716442B2 - Lever-type clamp - Google Patents

Description

S F Ref: 329993D1

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Actual Inventor(s): Address for Service: Hans Oetiker AG Maschinen- und Apparatefabrik Oberdorfstrasse 21 CH-8812 Horgen

SWITZERLAND

Hans Oetiker Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Lever-Type Clamp Invention Title: The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845

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FIELD OF THE INVENTION This invention relates to a clamp structure, and more particularly to a clamp structure with a lever-type closure mechanism for tightening the clamp.

SBACKGROUND OF THE INVENTION Clamp structures with lever-type closure mechanisms are known in the art. For example, a simple toggle-link in a clamp structure is shown in U.S. Patent 2,440,260. Another type of lever-actuated closure mechanism for a hose clamp is shown in iOFrench Patent 1,116,743. Commercially successful lever-type hose clamps are shown and described in applicant's own prior U.S. Patent 3,475,793, the contents of which are incorporated by reference in this application. Though the lever-type clamp structures in applicant's aforementioned U.S. Patent disclosed the use of ttensional spring elemnents in the form of lugs or folds, these folds or lugs left an opening underneath the same which had to be bridged by a separate bridging element to avoid the possibility of leakage within that area. This, in turn, increased the cost of manufacture by the need for separate parts in the form of bridging or *:.-connecting members which had to be installed manually. Economic reasons therefore normally prompted the omission of such tensional spring elements in the commercial versions of these lever-type clamp structures. Another problem noted from time to time with applicant's prior lever-type hose clamps was the unintentional .opening of the lever-type closure mechanisms.

-1- It is the object of the present invention to substantially overcome or at least ameliorate one or more of the prior art disadvantages.

Summary of the Invention There is disclosed herein a rivet-like connection for two mutually overlapping band portions of a clamping band, comprising connecting means for securely connecting together the overlapping band portions including two longitudinally extending tab-like members spaced in the band transverse direction and extending outwardly from the inner overlapped band portion bent up about axes extending in the longitudinal direction of the clamping band, a cold-deformed, deep-drawn support hook also extending outwardly from the inner overlapped band portion, aperture means in the overlapping band portion for engagement by said tab-like members and said support hook, said tab-like members having a height, after being bent up and extending through the corresponding aperture means which is sufficiently greater than the thickness of the overlapping band portion, to i5 establish a rivet-like connection by bending over the tab-like members over the outer surface of the overlapping band portion to hold it down onto the inner overlapped band portion.

•Preferably, said two tab-like members are spaced nearer the free end of the corresponding band portion than the support hook, and the aperture means are in the form 20 of two rectangular apertures.

Preferably, said two tab-like members are punched out of said inner clamping band portion substantially symmetrically with respect to the longitudinal center axis of the clamping band in such a manner that substantially equal amounts of clamping band remain on both outer sides of the tab-like members and a predetermined amount of 25 clamping band remains between the two tab-like members.

Preferably, said tab-like members are formed by oppositely directed, substantially U-shaped cuts in such a manner that the bending axes for the tab-like members are located near the longitudinal sides of the clamping band portion and are bent over said overlapping band portion in mutually opposite directions toward said longitudinal sides.

[R:\LIBLL]08973.doc:vjp J -3- BRIEF DESCRIPTION OF THE DRAWINGS Preferred forms of the present invention will now be described by way of example only with reference to the accompanying drawings, wherein: Figure 1, is a somewhat schematic axial elevational view of a first embodiment of a lever-type clamp structure in accordance with this invention; Figure 2 is a plan view on the clamping band used in the clamp structure of Figure 1; Figure 3 is a side elevational view of the clamping band of Figure 2; Figure 4 is partial top plan view of the lever-type closure mechanism in the closed position thereof, taken along line 4-4 of Figure 1; Figure 5 is a partial top plan view of the rivet-like connection obtained with a clamping band end section in accordance with this invention; Figure 6 is a partial cross sectional view taken along lines 6-6 of Figure 15 Figure 7 is a somewhat schematic axial elevational view, partly in cross section of a modified embodiment of a lever-type clamp structure with two standard clamping band end sections in accordance with this invention; *•ooo *•ooo [N:\LIBLL102520:MFF Figure 8 is a plan view on a typical perforated, socalled ladder-type clamping band used with the clamp structure of Figure 7; Figure 9 is a plan view on one standard clamping band end Ssection for the clamp structure of Figure 7; Figure 10 is a side elevational view of the clamping band end section of Figure 9; Figure 11 is a plan view on the other standard clamping band end section of the clamp structure of Figure 7; 1O Figure 12 is a side elevational view of the other clamping band end section of Figure 11; Figure 13 is a somewhat schematic partial axial elevational view of still another modified clamp structure of this invention with the lever-type closure mechanism in the open I position; a Figure 14 is a somewhat schematic partial axial elevational view, similar to Figure 13, with the closure mechanism in the closed condition; Figure 15 is a bottom plan view on the clamping band 3 Ogripping member of the closure mechanism of the clamp structure of Figure 13; Figure 16 is a side elevational view of the clamping band gripping member of Figure Figure 17 is a plan view on the connection of the -Astandard end section of the clamp structure of Figure 13 with the perforated clamping band by means of a separate connecting member; -4-

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Figure 18 is a cross sectional view taken along line 18-18 of Figure 17; Figure 19 is a cross sectional view taken along line 19-19 of Figure 17; Figure 20 is a side elevational view of the clamping band end section for the clamp structure of Figure 13; and Figure 21 is a top plan view of the clamping band end section of Figure DETAILED DESCRIPTION OF THE INVENTION 1 Referring now to the drawing wherein like reference numerals are used in the various views to designate like parts, and more particularly to Figures 1 to 6, reference numeral 10 generally 9. designates a lever-type clamp structure which includes a clamping band 11 that is connected with the lever-type closure mechanism 6-generally designated by reference numeral 20. The clamping band 11 which in this embodiment is made integral, in one piece, includes in the end portion lla' thereof two tab-like members 13a S• and 13b obtained by two mutually oppositely directed substantially U-shaped cuts and bent up about axes extending in the clamping band Olongitudinal direction so that the tab-like members 13a and 13b extend substantially parallel to one another in the center area of the clamping band. The two tab-like members 13a, 13b are followed by one cold-deformed, deep-drawn support hook 12 which may be realized by a more or less transversely extending cut in the ^aclamping band and subsequent pressing out by deep-drawing to provide an engaging surface 12', as more fully described in applicant's U.S. Patent 4,299,012. Spaced from the support hook 12 in a direction away from the free end of the band end portion Ila are two apertures 14 and 15, whereby support hook 12 is adapted to engage in aperture 14 and the two tab-like members 13a and 13b in aperture 15 once the band end portion lla, is bent back upon itself about the cross web 27 after being extending through slot 21, provided in the base portion 21 of the relatively fixed part of the closure mechanism 20, and leaving again through slot 21' to thereby form the underlying band end portion Ila' of the band end iOsection Ila. The end section Ila of the clamping band 11 is preferably fixedly secured to the relatively movable lever part of the closure mechanism 20 which can be readily achieved with the 0 S use of an impact tool bending the two tab-like members 13a and 13b outwardly into the plane of the clamping band as shown in greater K detail in Figure 6. With the use of an appropriately shaped impact tool, a rivet-like connection can be realized with a single impact in a very simple manner.

The other clamping band end section lib is provided with a predetermined number of undulations 17 which are covered from 4 below by the remaining band end portion lib, after' the clamping band end section lib is extended through the slot 21'' provided in the base portion 21 of the relatively fixed part of the closure mechanism 20 and then bent back upon itself as shown in Figure 1 to form the underlying band end portion llb'.

a, In addition to the base portion 21 provided with the two slots 21' and 21", the relatively fixed part of the closure mechanism 20 includes two side portions 22a and 22b integral with the base portion 21 and extending at substantially right angle to the base portion 21. The relatively fixed frame part 21, 22a, 22b of the closure mechanism 20 is made from sheet metal of appropriate ^thickness and its side portions 22a, 22b are spaced from each other a distance sufficient to accommodate the pivotal movement of the lever member generally designated by reference numeral 25 which itself is provided with an elongated U-shaped opening 28 open at the inner end thereof and interrupted about one-half to about twolOthirds of its length from the open end by the cross web 27 integral with the leg portions 25a and 25b defining the opening 28. The lower end area of the toggle-type lever member 25 is provided along the leg portions 25a and 25b with mutually oppositely and outwardly 9 directed pin-like pivot members 26a and 26b adapted to engage in i corresponding aligned pivot holes 29a and 29b provided in the side portions 22a and 22b.

To 'reduce the risk of inadvertent opening of the closure mechanism from its tightening position illustrated in Figure 1, two inwardly directed, mutually facing projections 24a and 24b are provided on the inside of the side portions 22a and 22b. Their location in the right hand corner area, as viewed in Figure 1, in the corner area which is traversed by the lever member during its movement from the open position, in which the lever is approximately in the 11 o'clock position, into the closed or "htightening position shown in Figure 1, is of some importance because in that location, the projections 24a and 24b can be made longer due to the greater flexibility of the side portions 22a and 22b the farther these projections are away from the base portion 21.

The lever member 25 consists of a generally curved 25 with a radius of curvature sufficiently large so that the lever member 25 can move freely into its tightening position without interference by the undulations 17 and terminates in a rectilinear end portion 25'' which extends outwardly when the lever member 25 is in the tightening position to facilitate reopening of 0 the closure mechanism. The lever portions 25' and 25'" are thereby so 'shaped and arranged that in the tightening position, as shown in Figure 1, the lower surface of the lever member 25 within the area of transition from the curved portion 25, to the rectilinear portion 25,' almost contacts the outer surface of the clamping band end section 11b. The leg portions 25a and 25b defining the elongated U-shaped opening 28 are thereby spaced at such a distance from one another that the clamping band 11 can extend therethrough.

As to the rest, the closure mechanism is of a construction as more *00 fully disclosed in applicant's aforementioned prior U.S. Patent and cltherefore will not be described in further detail.

In'the embodiment of Figures 1-6, the clamping band 11 is made in one piece and can be chosen to suit the needs of the particular application. By selecting a thicker and therewith stronger clamping band material, the clamp structure of this J2embodiment is also particularly suitable for heavy-duty -8applications. A typical example of a clamping band suitable for this embodiment is as follows, though it is understood that the present invention is not limited thereto but can be modified to satisfy the particular needs of a given application. For a clamp with a theoretical clamping range of about 77.5 mm. to about 81.5 mm. in diameter, the clamping band is made of galvanized steel having a width of 10 mm. and thickness of 0.5 mm. The overall length of the clamping band is 332.2 mm., the length of the tab-like members 13a, 13b in the longitudinal direction of the l Oclamping band is 3 mm. and the distance a is 8 mm. The length of the cold-deformed support hook 12 in the longitudinal direction is 2.'8 mm. and the distance b is 13.3 mm., while the apertures 14 and are 3.5 mm. in width and 3.3 mm. in length. The distance c is 74.5 mm. and the distance d is 5.5 mm. The maximum height of the >support hook 12 is about 1.8 mm. from the bottom surface of the clamping band to the top surface of the support hook, and the height of the tab-like members 13a, 13b from the bottom surface of the clamping band to the top of the bent-up tab-like members is about 2.4 mm. The width of the support hook is about 3.3 mm., and 0Othe mutually facing surfaces of the tab-like members are spaced 1.8 mm. The three undulations 17 extend over a length of about 14.1 mm. with a maximum depth from the plane of the clamping band in one direction only of about 2.85 mm. from the top surface of the clamping band to the peak bottom surface of the undulation. The of the undulations is spaced about 41.9 mm. from the corresponding end of the clamping band (distance For ease of -9assembly, it may also be desirable to pre-bend the clamping band for installation in the closure mechanism The rivet-like connection illustrated in Figures 5 and 6 offers several advantages over the riveted connection disclosed in Sapplicant's prior U.S. Patent 3,286,314. On the one hand, it offers a symmetrical stress distribution in the clamping band within the area of the tab-like members 13a and 13b leaving equal amounts of clamping band material on both outer sides of the tablike members as well as a predetermined amount of clamping band imaterial in the center area of the clamping band between the two tab-like members as contrasted with the asymmetric arrangement in applicant's prior U.S. Patent 3,286,314 in which the tab-like member as well as the slot receiving the tab-like member are located to one side of the clamping band. Additionally, the Ipresence of the cold-deformed support hook 12 assists in absorbing large tensional forces which may occur in the clamping band

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longitudinal direction, thereby obviating the need for the large impact forces required in the U.S. Patent 3,286,314 to achieve the *555*5 rivet deformation not only of the tab-like member but also of the I&underlying band portion. On the other hand, the holding ability of the connection illustrated Figures 5 and 6 is quite remarkable because tensional forces in the clamping band are absorbed by two symmetrically arranged tab-like members in conjunction with the absorption capability of the support hook which minimizes the ',;likelihood of failure of the clamping band as a result of tearing.

Applicant's prior U.S. Patent 4,622,720 discloses a connection utilizing two cold-deformed support hooks which come into operation after the two overlapping band portions are moved toward one another by a combined tab-like guide and support hook provided for that purpose with an inclined guide surface. Once the overlapping Sband portions are moved close to one another and the support hooks have become operative, the tensional forces in the clamping band are absorbed principally by the support hooks with the combined guide and support hook playing an assisting role. However, in the arrangement according to Figure 5 of this application, the two tablike members 13a and 13b continue to play a significant role at all times in absorbing the tensional forces in the clamping band whereby the bent-over tab-like members also assure immediate S cooperation between the engaging surface of the support hook 12 and the corresponding edge of aperture 14 because the outer clamping band portion is held down onto the inner band portion once the tablike members are bent over. The connection illustrated in Figure has therefore universal applicability where such a preassembly of overlapping band portions is desired, for example, in screw-type o••oe clamps of the type disclosed in applicant's prior U.S. Patent cO4,521,940.

The embodiment of Figures 7 through 12 illustrates a clamp structure which permits a "do-it-yourself" approach to obtain a clamp structure of any given size by the use of two standard clamping band end sections in conjunction with a closure mechanism similar to closure mechanism 20 of the embodiment of Figures 1 to -11- 4 and with a clamping band cut to the desired length by the user, for example, from a roll of commercially available perforated, so-called ladder-type clamping band 11' (Figures 7 and The standard clamping band end section generally designated by reference numeral 30 includes in its clamping band 31 two tab-like members 33a and 33b followed by a cold-deformed deep-drawn support hook 32 adapted to engage in apertures 35 and 34, respectively, whereby the dimension of these members and apertures are the same as corresponding parts in the embodiment of Figures 1 to 4. The i Iclamping band standard end section 30 includes additionally, starting from the bottom thereof as viewed in Figures 9 and 10, a short tongue-like extension 39 followed by two cold-deformed, deepoo drawn support hooks 38 which, in turn, are followed by a guide hook 37 adjoined by a preassembly hook 36 which is intended to hold Ithe clamping band end section 30 in a preassembly position with hooks 37 and 38 engaging in corresponding apertures of the cut ladder-type clamping band 11, or of another type clamping band provided with corresponding apertures. The tongue-like extension 39 thereby assures a stepless internal configuration in the area of QOconnection between the clamping band 11' and the end section 30 as more fully disclosed in applicant's prior U.S. Patents 4,315,348 and 4,299,012. The clamping band end section 30 is thereby secured again to the cross web 27 by way of the slot 21, in base portion 21 of the closure mechanism 20 of Figure i.

SThe other standard clamping band end section generally designated by reference numeral 40 includes a clamping band 41 -12provided with a tongue-like extension 46 at its left end, as viewed in. Figures 11 and 12, followed by two cold-deformed, deep-drawn support hooks 45 which in turn are followed by a guide hook 44 adjoined by a preassembly hook 43. Three undulations 42 are nearer the right end of the clamping band end section The right end section of the clamping band end part 40 is thereby extended again through slot 21', of the base portion 21 of the closure mechanism in such a manner that the undulations 42 as well as the hooks 43, 44 and 45 come to lie in the outer band end Cportion 41a with the undulations 42 covered from below by the underlying clamping band end portion 41b. Though it is understood that the present invention is not limited to the following dimensions, a typical example given only for purposes of illustration, for a clamp structure of the embodiment of Figures 'through 12, is as follows. The overall length of the clamping band end-section 30 is 112.4 mm. made from galvanized steel and having a width of 10 mm. and a thickness of 0.5 mm. As mentioned before, the dimensions and spacings of the members 33a, 33b and 32 as well as of the apertures 34 and 35 are the same as in the previous ,.4embodiment. The tongue-like extension 39 has a width' of about 3.2 mm. and a length of about 2.5 mm. The dimension f is 7.1 mm., the dimension g 4.9 mm. and the dimension h 6 mm. The dimension i is 5.5 mm. and the spacing j is 1.9 mm. The width of the hooks 37 and 38 is 3.3 mm. and their maximum height is about 2.2 mm. and 5S2 mm., respectively, while the width of the preassembly hook 36 is about 3 mm., extends from the top surface of the clamping band at -13right angle a distance of about 4.2 mm. and a distance of about 3.6 mm. in the band longitudinal direction substantially parallel to the plane of the clamping band. The dimension of the parts 46, 43 and 42 in the clamping band end section 40 which has an overall length of about 101 mm., is the same as those of the corresponding parts of the clamping band end section 30, whereby the three undulations 42 have the same dimensions as the undulations 17 of the embodiment of Figures 1-4. The dimension k in Figure 12 is thereby 41.8 mm. while the distance 1 is again 10 14.1 mm.

Figures 20 and 21 illustrate a clamping band standard end section generally designated by reference numeral 60 for use with a clamp structure of the type illustrated in Figures 13, 14, 15a, 15b and 15c of applicant's prior U.S. Patent 3,475,793. The elongated clamping band of the standard end section 60 includes two apertures 62 and 63 as well as three undulations 64. Though it is understood that the present invention is not limited thereto, a typical example of a standard end section 60, given for purposes of illustration only is as follows. The clamping band end section Xwhich is again made from galvanized steel, has an overall length of 81 mm. and again has a width of 10 mm. and a band thickness of mm. The apertures 62 and 63 have a length in the clamping band longitudinal direction of about 2.8 mm. and a width of about 6 mm.

and are spaced from one another about 2.2 mm. The aperture 62 is thereby also spaced from the right end of the clamping band end section 60 by a distance of 2.2 mm., the dimensions 2.8 mm., 6 mm.

-14and 2.2 mm. being matched to corresponding dimensions of the perforations in a commercially available ladder-type clamping band.

The standard clamping band end section 60 is thereby fastened to the base portion 121 of the relatively fixed part of the closure Smechanism generally designated by reference numeral 120 by being bent back upon itself after extending through slot 122", in such a manner that the undulations 64 are again covered from below by the underlying band end portion 61b. With the clamping band end section 60 illustrated in Figures 20 and 21, the bendingback may 1otake place appropriately at a distance of about 41.5 mm. from the right end thereof (distance m in Figure 20). The standard clamping band end section 60 is secured to the perforated clamping band 11' S by any known means, preferably by a connecting member generally designated by reference numeral 70 (Figures 13, 17, 18 and 19) having two main surface portions 71 and 72 each provided with an aperture 73 and 74 and with a pressed-out locking hook 75 and 76 whereby the hook 76 extends downwardly from the main surface portion 71 and the hook 75 extends upwardly from the main surface 999999 9 9 portion 72, mutually displaced by one aperture so that these hooks Oehgage from above and from below into aligned apertures 62 and 63 of the clamping band standard end section 60 and of the end apertures 11,1 in the perforated clamping band 11' when the surface portion 71 is bent down to extend parallel to the surface portion 72 and the edge portion 78 is bent over the surface portion 71 to <Aenclose the overlapping band portions and securely connect the same together by the hooks 75 and 76 which have a height to extend

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through the overlapping band portions. As to the rest, the clamp structure thus realized corresponds substantially to that of Figures 13 through 15c of the last-mentioned U.S. Patent and includes a clamping band gripping member 90 pivotally connected 'about the cross web of toggle lever 125 and having downwardly extending gripping teeth 91 to engage in apertures 11", of the clamping band and thereby to permit a step-by-step adjustment of the size of the clamp diameter as described in the U.S. Patent 3,475,793 without the drawbacks mentioned above and with the use of 10 a standard part that can be manufactured in a simple manner which provides a spring action to compensate for tolerances as also for oooo changes in the diametric dimension, for example, of a nipple over e which the hose is fastened due to thermal expansion.

The use of undulations, broadly speaking, is known ialready in the prior art, as evidenced, for example, by the French S Patent 2,470,275, the European Patent 0 491 609 and the U.S.

Patents 5,216,783; 4,919,682; 4,308,648; 2,012,543 and 1,349,789.

However, the present invention utilizes undulations in connection with a particular type of clamp, that is, a toggle-type clamp and Jypermits by simple means the avoidance of the aforementioned drawbacks encountered with the prior art clamps of this type provided heretofore with fold-like spring elements in the clamping band itself. Moreover, the location of the undulations near the connection of the end sections 11b, 40 and 60 with the closure rimechanism also lessens the likelihood of a loosening of this connection, even though not fixedly fastened, because tensional -16forces in the clamping band are now absorbed before they reach the connection.

While I have shown and described several embodiments in accordance with the present invention, it is understood that the is not limited thereto but is susceptible of numerous changes and. modifications as known to those skilled in the art. For example, the clamping band may also be made of stainless steel, bronze, brass or even nylon or the like. I therefore do not wish to be limited thereto but intend to cover all such changes and \Omodifications as are encompassed by the scope of the appended claims.

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Claims (4)

1. A rivet-like connection for two mutually overlapping band portions of a clamping band, comprising connecting means for securely connecting together the overlapping band portions including two longitudinally extending tab-like members s spaced in the band transverse direction and extending outwardly from the inner overlapped band portion bent up about axes extending in the longitudinal direction of the clamping band, a cold-deformed, deep-drawn support hook also extending outwardly from the inner overlapped band portion, aperture means in the overlapping band portion for engagement by said tab-like members and said support hook, said tab-like members having a height, after being bent up and extending through the corresponding aperture means which is sufficiently greater than the thickness of the overlapping band portion, to establish a rivet-like connection by bending over the tab-like members over the outer surface of the overlapping band portion to hold it down onto the inner overlapped band oo portion.

2. A rivet-like connection according to claim 1, wherein said two tab-like members are spaced nearer the free end of the corresponding band portion than the oooo support hook, and the aperture means are in the form of two rectangular apertures.

3. A rivet-like connection according to claim 1 or 2, wherein said two tab- like members are punched out of said inner clamping band portion substantially 20 symmetrically with respect to the longitudinal center axis of the clamping band in such a manner that substantially equal amounts of clamping band remain on both outer sides of 9, 0: the tab-like members and a predetermined amount of clamping band remains between the two tab-like members.

4. A rivet-like connection according to any one of claims 1 to 3, wherein O 25 said tab-like members are formed by oppositely directed, substantially U-shaped cuts in such a manner that the bending axes for the tab-like members are located near the longitudinal sides of the clamping band portion and are bent over said overlapping band portion in mutually opposite directions toward said longitudinal sides. A rivet-like connection substantially as hereinbefore described with reference to Figs. 1 to 6; Figs. 7 to 12; or Figs. 13 to 21 of the accompanying drawings. Dated 23 December, 1999 Hans Oetiker AG Maschinen-undApparatefabrik Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON [R:\LIBLL]08973.doc:vjp