Crimp-Type Clamp

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject invention is directed to hose clamps and, more particularly, hose clamps that are secured by means of a crimping device.

2. Description of the Prior Art

For may years, clamps and bands have been made for a broad range of purposes. Many types and styles of such clamps have been developed with particular regard to securing flexible hose. Examples are shown in U.S. Pat. Nos. Re. 9,041 and U.S. Pat. No. 2,163,048. Among these types are crimp-type clamps which are secured to the hose by crimping an extended portion or "hat" of the clamp with a crimping tool. Examples of such clamps are shown in U.S. Pat. Nos. 4,222,155; 3,295,176; 3,286,314; 3,082,498; 3,602,954; 3,020,631; Re. 25,769; 3,523,337; and 3,402,436.

Crimp-type clamps are best suited for light duty applications that do not require the performance afforded by more elaborate types of clamps such as screw-type clamps. Some types of crimp-type clamps developed in the prior art are relatively complex and, therefore, somewhat difficult and expensive to manufacture. Generally, to limit manufacturing costs, crimp-type clamps are usually formed from a strip of flat stock with the ends of the stock being welded or mechanically coupled in an overlapped arrangement at some point along the sealing surface. However, such arrangements incorporate discontinuities in the sealing surface and provide irregular and low sealing pressure along the sealing surface at a location remote from the crimped portion. Thus, such prior art clamps establish a potential for fluid leakage within a zone of the sealing surface that is remote from the crimped portion. Accordingly, there was a need for a crimp-type sealing clamp that avoided such low-pressure zones along the sealing surface where there was a higher potential for leakage.

Prior art crimp-type clamps also had a zone of relatively low sealing pressure adjacent the ends of the sealing surface that were connected to the hat portion. This zone of low pressure was due to the relatively weak tangential force applied to the ends of the sealing surface by the crimped extended portion. In attempting to overcome this problem, a special crimping tool was developed that would support the top portion of the crimping section so that the top portion would not buckle during the crimping process. However, the crimp-type clamps requiring this special type of crimping tool could not be used with the standard crimping tool. This required users of crimp-type clamps to have both types of crimping tools or, alternatively, to limit themselves to the use of only one type of clamp. Preferably, therefore, the crimp-type clamp having the continuous sealing surface between the hat portion should be compatible with either type of crimping tool.

In accordance with the subject invention, a crimp-type hose clamp provides a continuous seal between the ends of a hat section. To provide the continuous sealing surface, the ends of the strip that forms the clamp are connected to form the top portion of the hat section. Preferably, the ends of the strip are overlapped by and butted against each other such that they are compatible with either style of crimping tool. Also preferably, the ends are connected together by a cooperating tab and slot arrangement. Alternatively, they can be welded or fastened together with a suitable bonding agent.

Other details, objects and advantages of the invention will become apparent as the following description of a presently preferred embodiment thereof proceeds.

The accompanying drawings show a presently preferred embodiment of the invention wherein:

FIG. 1 is a perspective view of a hose clamp embodying the present invention;

FIG. 2 is a partial elevational view of the clamp shown in FIG. 1 taken along the lines II--II of FIG. 1.

FIG. 3 is a partial cross-sectional view of the clamp shown in FIG. 1 taken along the lines III--III in FIG. 1.

FIG. 4 is a plan view of the unassembled strip that forms the hose clamp herein disclosed.

FIG. 5 is a partial elevational view of the assembled strip of FIG. 4 showing the hat portion in its assembled, unpressed state.

FIG. 6 is a partial cross-section of the assembled strip of FIG. 4 showing the hat portion in its assembled, unpressed state.

FIGS. 7, 8 and 9 are elevational views of the hat portions of three alternative embodiments of the clamp shown in FIGS. 1-3.

FIGS. 1-14 3 show a hose clamp according to the subject invention wherein a metal strip is formed in a continuous c-shaped clamping surface 10 and the ends of the metal strip are interlocked in a double-layered hat section 12. Double-layered hat section 12 includes offset sections 14 and 16 that are connected to the ends of clamping surface 10. Also included in hat section 12 is a double-layered top section 18 having opposite ends connected to one of the offset sections 14 or 16.

As shown more particularly in FIGS. 2 and 3, double-layered top section 18 includes a first layer 20 provided with obliquely aligned slots 22 and 24, and a second layer 26 provided with tabs 28 and 30 located in registry with slots 22 and 24 and detented so that first and second layers 20 and 26 are interleaved in a double layer structure with tabs 28 and 30 interfacing with first layer 20 on one side and the remaining portion of layer 26 interfacing with first layer 20 on the opposite side.

To provide increased rigidity in the corners of hat section 12, first and second layers 20 and 26 are sized such that end portions 32 and 34 of tabs 28 and 30 are in contact with or closely adjacent the internal face of offset section 14 and the end portion 36 of layer 20 is in contact with or closely adjacent the face of offset section 16. The increased rigidity of the double-layered hat section 12 makes the presently disclosed crimp-type hose clamp compatible with any commonly available style of crimping tool.

The diagonal angle oc of slots 22 and 24 and tabs 28 and 30 in top section 18 is such that end portions 32 and 34 and end portion 36 extend over a substantial portion of the width of the clamp. Thus, during the crimping operation, end portions 32, 34 and 36 distribute the compression load of the crimping force over substantially the entire width of the clamp.

The manufacture of the crimp-type clamp herein disclosed is explained with particular reference to FIGS. 4-6. Preferably, the clamp is cold-formed from a metal strip having shaped ends such as shown, for example, in FIG. 4. The first end of the metal strip of FIG. 4 is provided with obliquely arranged slots 22 and 24 at one end. The second end of the strip is provided with lateral cuts 38 and 40 that are recessed from ends 32 and 34 in correspondence with the distal ends of slots 22 and 24 from end 36. Preferably, the second end of the strip is joggled adjacent lateral cuts 38 and 40. The metal strip is then cold-formed to provide the continuous c-shaped sealing section 10 and the hat section 12. Specifically, the first and second ends of the strip are joined to form double-layered top section 18 of hat section 12 by bending the corner portions of the second end of the strip to form tabs 28 and 30 and inserting tabs 28 and 30 through slots 22 and 24 in the first end of the strip. The first and second ends of the strip are then detented by folding tabs 28 and 30 back against the first end of the strip to form a three-layered top section as shown in FIGS. 5 and 6. The three-layered top section is then placed in a press and compressed into two-layered top section 18 shown in FIGS. 1-3 wherein top section 18 has a thickness that is substantially equal to twice the thickness of the metal strip. In addition to the additional strength provided by the interleaved double-layer structure of top section 18, the cold forming processing technique provides double-layered top section 18 with additional metallurgical strength to resist buckling during the crimping operation.

FIGS. 7, 8 and 9 show alternative embodiments of the hat section of the crimp-type clamp herein disclosed. In FIG. 7, top section 18 is provided with a concave curvature such that the top section further resists buckling during the crimping operation. In the hat section shown in FIG. 8, offset sections 14 and 16 are located in non-parallel relation such that they converge toward each other adjacent the junctions between sections 14 and 16 clamping surface 10. It has been found that the arrangement shown in FIG. 8 wherein the respective ends of sections 14 and 16 adjacent clamping surface 10 are closer than the respective ends of sections 14 and 16 adjacent top section 18 also provides further resistance to buckling of top section 18 during crimping. FIG. 9 shows another embodiment of the disclosed hat section that incorporated both the advantages of the concave clamping surface shown in FIG. 7 and the advantages of the converging offset sections shown in FIG. 8.

While a presently preferred embodiment of the invention is shown and described, the invention is not limited thereto, but may be otherwise variously embodied within the scope of the following claims.