AN IMPROVED HOSE CLAMP

Abstract: An improved hose clamp of the kind comprising a steel strip (1) bent to annular shape with the end portions (1', 1'') overlapping. The radially outer one (1'') of the end portions is formed with a threaded passageway (5) having transverse grooves in which engage the threads (4) of a screw worm (3) which is rotatably journalled in a sleeve (2) but axially non-slidable therein. The sleeve encloses the screw worm and comprises a space allowing the outer strip end portion (1'') to be displaced through the sleeve (2) between the inner strip end portion (1') and the screw worm (3) by rotating the latter. The part of the inner strip end portion (1') which is positioned closest to the longitudinal axis of the screw worm is provided with a punched portion (12) and with an upset portion provided at the side of the punched portion positioned closest to the free end of the inner strip end portion (1'). The upset portion (11) is positioned in a notch (10) formed in the radially inner one of the screw worm sleeve walls so that an edge face (10') formed by the notch in the screw worm sleeve (2) forms an abutment face against the edge face (11') of the upset portion (11).

Description: An Improved Hose Clamp The subject invention relates to an improved hose clamp of the kind comprising a steel strip which is bent to annular shape with the ends of the strip overlapping, the radially outer end portion of the strip being formed with a threaded passageway having transverse grooves in which engage the threads of a screw worm, the latter being rotatably journalled in a sleeve but axially non-slidable therein, said sleeve enclosing the screw worm and comprising a space allowing the outer strip end portion to be displaced through the sleeve between the inner strip end portion and the worm by rotating the latter. In hose clamps of the kind outlined above the radially inner strip end portion must be secured relative to the screw worm sleeve. Usually, interlocking of these components is effected by cooperation between a notch punched in the inner strip end portion and an upset portion of the worm sleeve in engagement with said notch. The upset portion extending towards the interior of the sleeve must be given a well-defined vertical edge face in order to bring about the desired secure engagement thereof in the notch. Consequently, the tools used to form the interlocking means must meet very strict demands on exactness as the manufacture is fully automated and performed at very high speeds. For the purpose of providing the interlocking effect between the inner strip end portion and the worm sleeve in a simpler manner it has been suggested to provide the inner strip end portion with stamped sections at each end of the worm sleeve and with downwardly bent sections which form a back-up face to the worm sleeve when the punched edge face abuts against the latter. However, this solution has proved disadvantageous because when the hose clamp is tightened about a hose of an elastic material the latter has a tendency to force the locking parts of the inner strip end portion outwards out of their engagement with the end edges of the worm sleeve. This is due to the possibility of vertical strap play at the end edges of the sleeve, which is partly due to the necessity of OftiPI allowing space to permit simple insertion of the outer strip end portion into the worm sleeve. The purpose of the subject invention is to provide interlocking means which allow safe securement of the worm sleeve relative to the inner strip end portion and which may be manufactured at a high rate of production and in a considerably more convenient manner than is the case of prior-art locking means devised for the purpose. The invention is character zed therein that the part of the inner strip end portion which is closest to the lengthwise axis of the screw worm is provided in a section across the width with a punched portion and with an upset portion positioned on the side of the punched portion which is closest to the free end of the inner strap end portion, said upset portion being positioned in a notch formed in the radially inner one of the walls of the worm sleeve, whereby an edge formed by said notch in said worm sleeve wall forms an abutment face against the edge face of said upset portion. One embodiment of the invention will be described in closer detail in the following with reference to the accompanying drawings, wherein Fig. 1 is a lateral view of a hose clamp in accordance with the invention, said figure also including a vertical sectional view through the clamp worm sleeve, Fig. 2 is a sectional view along line II—II of Fig. ' l, Fig. 3 is a sectional view along line III—III in Fig. 1 and Fig. 4 is an enl argement of a part of the inner str p end porti on. The hose cl amp consi sts of a steel stri p 1 which is bent to annul ar shape and the two end portions 1 ' , 1 " of whi ch are arranged in overl apping position insi de a worm sleeve 2. A screw worm 3 is rotati onally jourπal l ed but axial ly non-sl i dabl e i nsi de the sleeve 2. The threads 4 of the screw worm engage transverse grooves 5 formed in the strip. The worm is provi ded wi th a hexagonal head 6 OMPI having a groove 7 formed therein for engagement with a screw driver. The screw worm 3 also is formed with a peripherally extending channel 8 adjacent the head 6 and a marginal portion 9 of the sleeve 2 is inserted into said channel 8 through upsetting. Owing to the upset portion inside the channel 8 the worm is prevented from moving axially relative to the sleeve 2. The radially inner wall of the screw worm sleeve 2 is formed with a notch 10 which is positioned in the proximity of the longitudinal axis of the screw worm 3. The notch 10 preferably is rectangular with one of its edge faces 10' extending at right angles to the lengthwise extension of the strip 1 through the sleeve 2. The inner strip end portion 1' is formed with a portion 11 which is upset to project radially inwards in engagement with the notch 10. The upset portion 11 is shown on an enlarged scale in Fig. 4. As appears from this drawing figure the upset portion 11 is formed so as to connect with a punched portion 12 in the inner strip end portion I 1 . The punched portion 12 is slightly arcuate and its ends are rounded. Owing to the arcuate configuration of the punched portion 12 in the manner appearing from Fig. 4 an edge face 11' is produced in the upsetting operation, which face projects essentially at right angles from the plane of the strip, which provides secure abutment against the edge face 10* of the notch. The rounded configuration of the ends of the. punched portion prevents the formation of sharp fillets or indications of fractions in the course of the simultaneous or subsequent upsetting operation. Because the notch 10 formed in the wall of the screw worm sleeve 2 is comparatively small the sleeve wall is not " weakened to any significant extent. Nor does the punched portion 12 of the inner strip end portion 1' result in any significant weakening effect. The opposite si e wall of the upset portion 11 may be made comparatively -steep since the upset portion provides a secure abutment grip of the strip end portion relative to the worm sleeve in the opposite direction as.well. The stress exerted in this opposite direction is however, as a rule, comparatively small. The operational steps required to effect the interlocking of the strip end portion rel tive to the worm sleeve as described above may be effected by means of simple and automated, tools operating at a very high speed. Since the details cooperating to provide the interlocking effect are positioned in immediate proximity to the lengthwise axis of the screw worm the radially outer strip end portion I 11 together with the screw worm 3 and the radially outer part of the worm sleeve 2 form efficient hoiding-up means preventing the upset portion 11 from disengagement from its position inside the notch 10. Because the back-up face of the upset portion 11 is formed by one of the edges faces 11' of the punched portion this face may easily be given optimum configuration. The deformation of the inner strip end portion 1' that the rest of the upset portion 11 involves is favourable from the point of view of strength and increases the resistance of the material to stress exerted in the axial direction of the strip 1. The invention is not limited to the embodiment described in the aforegoing but several . variations and modifications are possible within the scope of the appended claims. The design of the notch 10, the punched portion 12 and the upset portion 11 could be different from the one shown. The inner strip end portion 1' can be provided at the two end edges of the worm sleeve 12 with bent portions in a manner known per se to provide smooth transitional areas between the inner face of the strip and the sleeve. OMPΪ

Claims: C L A I M S 1. An improved hose clamp of the kind comprising a steel strip (1) which is bent to annular shape with the end portions (1', 1'') of the strip overlapping, the radially outer end portion (1 ) of the strip being formed with a threaded passageway (5) having transverse grooves in which engage the threads (4) of a screw worm (3), the latter being rotatably journal led in a sleeve (2) but axially non-slidable therein, said sleeve (2) enclosing said screw worm and comprising a space allowing the outer strip end portion (l 11 ) to be displaced through the sleeve (2) between the inner strip end portion (l 1 ) and the screw worm (3) by rotating the latter, said inner strip end portion (l 1 ) being provided in a section across the width at the part positioned closest to the longitudinal axis of the screw worm (3) with a punched portion (12), c h a r a c t e r i z e d therein that the inner strip end portion (1') additionally is provided on the side of the punched portion (12) which is closest to the free end of the inner strip end portion (1') with an upset portion (11) which is so positioned, in a. notch (10) formed in the radially inner one of the walls of the screw worm sleeve (2) that an edge formed by. said notch (10) in sa d screw worm sleeve wall serves as an abutment face against the edge face (11') of said upset portion (11). 2. An improved hose clamp as claimed in claim 1, c h a- r a c t e r i z e d therein that the punched portion (12) in addition to * extending in a section across the width of the inner strip end portion (1') likewise extends in the lengthwise direction of the strip end portion and is formed by two circular parts and one straight or arcuate part interconnecting the circular parts. -gU EA OMPI

Inventors: FINCK KLAUS, RIBRANT SVEN, FINCK, KLAUS, RIBRANT, SVEN
Applicants: ALLMAENNA BRANDREDSKAPSAFFAERE, ALLMAENNA BRANDREDSKAPSAFFAEREN AB
Application year: 1984
Main classification: F16L33
IPC codes: A63H18, A63H19, A63H29, F16L33