High strength clamp structure

Abstract: A hose clamp (10) with an ear-like structure (12) which is adapted to be selected strengthened to achieve desired holding ability and/or re-tightening forces, as needed. This is achieved in one embodiment by complementary ear-like structures (12a, 12b) in the overlapping inner and outer band portions (11a, 11b) with the free ends of the inner and outer band portions connected with the corresponding overlapping, respectively, overlapped band portion. In addition or in the alternative, the ear-like structure (12) is strengthened by external and/or internal strengthening members (35; 135; 130a, 130b, 130c, 240) made of spring steel with predetermined spring characteristics whereby in one particular realization, the strengthening member (35; 135; 130a, 130b, 130c, 240) can be readily installed and disassembled from the ear-like structure (12) by the insertion and removal of pin-like retaining members (237).

Description: FIELD OF INVENTION The invention relates to hose clamps with an ear-like structure strengthened to increase the holding ability thereof. BACKGROUND OF THE INVENTION Various attempts have been made heretofore to strengthen ear-like structures of clamps, especially hose clamps, in order to increase their holding ability and/or their spring properties which determine the elastic re-tightening forces in case of expansion of the hose clamp due to temperature and/or pressure increases. For example, narrow reinforcing grooves of more or less canoe shape as viewed in plan view have been proposed in U.S. Patent 3,475,793 for the bridging portion of so-called "Oetiker" ears. U.S. Patent 3,510,918 proposed the use of an elastic insert member to control the elastic properties of the ear. A plug made from rod-shaped elastic material or hollow spring steel was also proposed in U.S. Patent 3,579,754. Considerable improvements for increasing the holding ability of ear-like structures were attained with a reinforcing depression provided in the bridging portion of the ear-like structure, as more fully disclosed in British Patent 2,160,577. According to this application, the reinforcing depression is a relatively shallow, generally pan-shaped depression of generally rectangular shape as seen in plan view with the sides extending over substantial portions of the width and length of the bridging portion in its non-reinforced condition. Though the various ways of increasing the holding ability of ear-like structures and/or controlling the elasticity thereof, as proposed heretofore by me, have proved very successful, the advent of new hose materials and/or applications to ever-greater ranges of temperature and/or pressure changes demand ever-improved characteristics in hose clamps. Proposals have also been made heretofore by others to address these and other problems. For example, the U.S. Patent 3,087,221 proposed a hose clamp which had its greatest radial band thickness near the middle with the thickness progressively reduced towards the ends for the avowed purpose to maintain a true circle initially and upon change of diameter. In Figure 3 of this patent, the ear itself was also proposed to be made in the same manner as the clamping band, i.e., having its greatest thickness in the middle with reduced thickness toward the ends of the ear. Apart from a lack of disclosure of how the clamps as proposed in this patent could be realized in practice, this patent was concerned only with maintaining a true circular configuration of the parts in question. The European Patent 0 208 598 discloses a clamp with an elasticity reserve which is obtained by the use of a spring constituted by a simple, generally cylindrical sleeve which is mounted externally over the loop integral with the clamping band. In case of increase in the diametric dimension of the clamp, the connecting zones of the ends tend to move away from one another, resisted by the elasticity reserve, whereby maximum spacing between these zones is precluded by the abutments and adapted to engage in rectangular openings. Another approach to affecting the holding ability of a so-called "Oetiker" ear can be found in Swiss Patent 580,247 in which the plastically deformed ear can be subjected only to a predetermined maximum reopening force. However, the force for reopening the ear up to its maximum limit is unaffected by this arrangement. The more recently issued U.S. Patent 4,430,775 proposed a banding strap for attaching a heat shield to a muffler in which the overlapping band portions were provided with outwardly projecting folds so constructed and arranged that the fold in the inner band is received in the bite of the fold in the outer band. The inner and outer bands are held in position by a "snap-in" feature preventing the folds from springing apart before they can be crimped together. Furthermore, lateral misalignment is intended to be prevented by dimples which also add material strength and stiffness to the central sections of the folds. However, tests have indicated that the nesting arrangement of the folds as disclosed in this patent will not, as such, materially strengthen the fold's holding ability over that in a hose clamp with a similar fold but constituted only in the outer band portion, i.e., by a single band layer. SUMMARY OF THE INVENTION It is the object of the present invention to provide an ear-like structure in hose clamps which offers greatly improved holding characteristics and re-tightening spring characteristics which can be accurately controlled in accordance with the requirements of a given situation. Preferably, the ear-like structure for hose clamps should permit its strength and spring characteristics to be selectively modified by extraordinarily simple means. This object is met by the hose clamp defined in claim 1. According to the invention, a clamp can be obtained whose ear-like structures can be readily controlled by the insertion of a strengthening member which is so connected with the clamping band that an expansion of the hose clamp due to an increase in temperature and/or pressure will seek to open the gap underneath the ear-like structure. The internal strengthening member thereby opposes such movement of the ear-like structure, whereby the ear-like structure is so constructed and arranged in conjunction with pin-like retaining members that the strengthening member can be readily assembled into the ear-like structure and disassembled therefrom whereby removal of the pin-like retaining member is realized by merely compressing the ear-like structure. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a partial axial elevational view through still another modified embodiment of a hose clamp with an internal strengthening member in accordance with the present invention which is removably connected with the ear-like structure by way of removable pin-like retaining members; Figure 2 is a bottom plan view on the hose clamp of Figure 1; Figure 3 is a cross-sectional view, taken along line 3-3 of Figure 2; Figure 4 is a cross-sectional view, similar to Figure 3 in which the ear-like structure is compressed to permit removal of the pin-like retaining members; and Figure 5 is a bottom plan view on the arrangement of Figure 4, also indicating the removed pin-like retaining members. DETAILED DESCRIPTION OF THE DRAWINGS Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, an embodiment in accordance with the present invention for a hose clamp is illustrated, which has a readily interchangeable spring-like strengthening member in the ear-like structure. The hose clamp of this embodiment, of which only a part of the clamping band is shown and designated by reference numeral 211 includes an ear-like structure generally designated by reference numeral 230 which has a substantially rectilinear main portion 231 adjoined by at least approximately semi-circularly shaped lateral portions 232 terminating by way of end portions 234 in nearly semi-circularly shaped connecting portions 233 having a radius of curvature smaller than the radius of curvature of the lateral portions 232. The rounded-off connecting portions 233 thereby connect the nearly horizontally extending end portions 234 (Figure 1) with the clamping band 211. The end portions 234 as well as the connecting portions 233 are thereby provided each with a central aperture 235 extending also a slight distance into the clamping band so that a strengthening member 240 of suitable spring material and approximately semi-circular shape can be installed through the openings 235 with its leg portions 241a and 241b extending into openings 235 as shown in Figure 3. The strengthening member 240, which is made of appropriate thickness and suitable spring material, thereby exerts by its leg portions 241a and 241b forces on pin-like retaining members 237 and by way of the latter on the connecting portions 233 seeking to close the gap underneath the ear-like structure, i.e., seeking to tighten the hose clamp. The pin-like members 237 thereby extend through the space between the rounded-off connecting portions 233 and the leg portions 241a and 241b. The strengthening member 240 is of such shape that its leg portions 241a and 241b are spread apart from their normal position in the installed position thereof shown in Figure 3, so that the strengthening member 240 will apply an elastic force increasing the strength of the ear-like structure 230 to oppose expansion of the hose clamp by opening of the gap underneath the ear-like structure 230. The strengthening member 240 thereby has a width less than the width of the openings 235 so that it can be easily removed from within the ear-like structure 230 after the pin-like members 237 are withdrawn. This can be easily done by applying oppositely directed force onto the lateral portions 232 as indicated by the arrows in Figure 18 which will effectively increase the space between the leg portions 241a and 241b and the connecting portions 233 so that the pin-like members 237 can drop out, whereby the strengthening member 240 will also drop out as soon as the retaining pin-like members 237 are removed. Thus, the embodiment of Figures 1 to 5 provides a hose clamp in which, in addition to the ear-like structure 230, an increased elastic tightening force can be achieved by the use of the strengthening member 240 made, for example, of appropriate spring steel. By merely compressing the ear-like structure 230, the two pin-like members 237 will drop out and for reassembly it is only necessary to insert the strengthening member 240 and thereafter again compress the ear-like structure 230 so as to be able to then reinsert the pin-like members 237. While I have shown and described several embodiments in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art. For example, the embodiment of Figures 1-5 is not limited to one ear structures, but the features disclosed are equally applicable to two-ear structures or multi-ear structures, possibly made from several parts, which are connected as shown, for example, in Figure 27 of U.S. Patent No. 4,299,012 and which are then suitable for larger diameters and greater clamping ranges as well as greater expansion.

Claims: A hose clamp comprising a clamping band (211) and ear-like means (230) operatively associated with the clamping band (211) to enable elastic changes in the diametric dimensions of the hose clamp, the ear-like means (230) forming a gap in the circumferential direction and being operable to enlarge the gap underneath the ear-like means (230) in the presence of forces seeking to enlarge the diametric dimensions of the hose clamp, further means being operatively associated with the ear-like means (230) and separate from the clamping band for selectively changing the spring characteristics of the ear-like means (230) to adapt the same to existing requirements including spring-like means (240) located inside the ear-like means (230), said further means cooperating with said ear-like means (230) in such a manner that said spring-like means (240) is operable to resist enlargements in the gap underneath the ear-like means (230) brought about by forces seeking to expand the hose clamp to thereby strengthen the holding ability of the ear-like means (230) and at the same time increase the re-tightening forces when the forces seeking to expand the hose clamp subside. The hose clamp of claim 1, wherein said spring-like means (240) is held in place by retaining means (237) provided inside of the ear-like means (230) and having one side supported by said clamping band (211) and the other side engaged by said spring-like means (240). The hose clamp of claim 2, wherein the retaining means are pin-like members (237) adapted to be removed by compression of the ear-like means (230), the pin-like members (237) being held fast between externally open, rounded-off connecting portions (233) which connect the ear-like means (230) with the clamping band (211) and partially surround the pin-like members (237) on one side, said spring-like means (240) engaging the pin-like members (237) on the other side. The hose clamp of claim 3, wherein openings (235) are provided in the connecting portions (233), the width of said spring-like means (240) being smaller than the width of the openings (235), and wherein the spring-like means (240) is of substantially U-shape with its free leg portions (241a, 242b) extending into the openings (235).

Inventors: OETIKER HANS, OETIKER, HANS
Applicants: OETIKER HANS MASCHINEN, HANS OETIKER AG MASCHINEN- UND APPARATEFABRIK
Application year: 1992
Main classification: F16L33
IPC codes: F16L33, F16B2