Method Of Making Hose Clamps

Abstract

A metal strip having a width equal to the length of each hose clamp that is to be cut from it is fed forward intermittently. While the strip is stationary parallel slots are punched in it in parallel rows extending transversely of it, with the ends of the rows spaced from the edges of the strip. Strip material between each edge of the strip and the adjacent ends of alternate rows of the slots is stamped out to leave a row of heads along each edge of the strip staggered relative to those along the opposite edge. The head are provided with lugs extending in opposite directions lengthwise of the strip. The lugs are then bent up and an open-bottom screw housing is placed on each head. The screw housings have wide flanges provided with openings receiving the lugs, which are then bent down against the flanges to lock the housings on the heads. After this last operation the strip is fed ahead and severed transversely midway between the leading row of slots and the next succeeding row to form a hose clamp band with a screw housing secured to one end.

Description

The conventional way of making hose clamps is to cut the clamp bands from a narrow strip of metal that is no wider than the bands. The bands therefore have a uniform width from end to end. Then, either a one-piece or a two-piece screw housing is attached to one end of the band. When a two-piece housing is used, the lower part engages the bottom or inside of the band. When a one-piece housing is applied it is provided with inwardly projecting portions that likewise engage the bottom of the band. In either case, the portion of the screw housing beneath the band is added to the thickness of the band above it so that a considerable gap may be left between the object being clamped and the free end portion of the band where it enters the screw housing. Also, the construction and application of the known two-piece and one-piece housings to the clamping bands have been relatively expensive.

It is among the objects of this invention to provide a hose clamp of simpler construction than heretofore, which is less expensive to make, and which provides more complete engagement with the object being clamped. Other objects of the invention are to provide a method of making hose clamps which is rapid and less expensive than heretofore.

The invention is illustrated in the accompanying drawings, in which

FIG. 1 is a fragmentary schematic side view of a metal strip being formed into hose clamps;

FIG. 2 is a plan view thereof with some of the dies indicated by cross hatching;

FIG. 3 is an enlarged fragmentary side view of a completed clamp; and

FIG. 4 is a cross section taken on the line IV--IV of FIG. 3.

Referring to FIGS. 1 and 2 of the drawings, a flat strip 1 of metal of the correct gauge for making hose clamp bands is fed forward intermittently over a supporting plate 2 in any suitable manner, such as by intermittently driven rolls (not shown). The strip passes through apparatus by which hose clamps are formed from the strip. The metal strip that is selected has a width equal to the length of the bands that are to be cut from it because, contrary to the usual practice, the bands extend transversely of the strip as they are cut from it and not lengthwise of the strip. One edge of the strip engages a fixed guide 3 while the opposite edge engages an adjustable guide 4 so that strips of different widths can be used to provide clamping bands of any desired length.

The apparatus includes means for punching, stamping, bending and cutting the strip. This is done by vertically reciprocable members above and below the strip. Some are attached to a lower ram 6 and the rest are attached to an upper ram 7. All are adjustable on the rams and removable from them. There are two sets of most of these members on each ram, one for each edge portion of the strip. The strip is punched by dies 8 and 9 to form a row of longitudinally spaced rectangular openings 10 near each edge. The openings in one row are staggered relative to those in the other row. Other dies 11 and 12 punch groups of parallel slots 13 in the strip in parallel rows that extend transversely of it. Each row of slots is in a position to align with one of the rectangular openings 10, so alternate rows are aligned with the openings along one side of the strip and the rest of the rows are aligned with the openings along the opposite side.

Between openings 10 along each side of the strip the material is stamped out to form notches 15 of special shape by means of dies 16 and 17. The result is that heads 18 are left between the notches, with one of the rectangular openings 10 at the center of each head. The notches are so shaped that each head is provided with a pair of integral lugs 19 extending in opposite directions lengthwise of the strip.

After any given head is formed, its lugs are bent upwardly between upper and lower dies 21-22 and 23-24. Following this, an open-bottom one-piece screw housing 25 is placed on the head. As shown in FIGS. 3 and 4, this housing has side flanges 26 provided with vertical openings 27 that receive the upstanding lugs 19. The flanges rest on shoulders 28 near the bottom of the lugs. The housing is placed on the head by any suitable mechanism that can pick it up and transfer it to the head, or even by hand. After the strip moves ahead again the lugs are bent down on the flanges to lock the housing in place. This is done by staking tools 30 and 31 carried by the upper ram 7. The purpose of the housing is to contain the usual tightening screw 33. Such a screw can be inserted in the housing after the housing has been applied to the head, but it is preferred to insert the screw in the housing first and then place both of them on the head at the same time.

With a screw and housing in place, the strip is moved ahead again and then it is severed transversely midway between the leading row of slots 13 and the next succeeding row, whereby a hose clamp band 35 is produced that has a screw housing and tightening screw attached to one end. The band can be sold flat as it is, or the free end of the band can be curved around and inserted in the screw housing with the screw thread projecting through the band slots and into the underlying rectangular opening 10 as shown in FIG. 4.

For efficient operation, the distance the metal strip is fed ahead each time should equal the width of the two bands 35. With such a feed, two bands can be cut from the strip simultaneously by severing the strip between the second and third rows of slots 13 at the same time that it is severed between the first and second rows. The severing can be done by upper and lower shear blades 36 and 37.

It will be seen that with this hose clamp no part of the screw housing extends beneath the band, so the band can form a more nearly perfect circle because where the free end portion of the band enters the housing it will be spaced from the clamped object by only the thickness of the band and not by any part of the housing. Also, the form of the housing is simplified. Its manner of attachment to the band is very simple and inexpensive. If such a band were formed in the old manner, the metal strip from which it was cut would have to be as wide as the head of the band plus its laterally projecting lugs before they are bent up. This would mean that there would be considerable waste of material as the opposite sides of the strip were cut away to form the head and lugs. On the other hand, with the method disclosed herein, in which the bands extend crosswise of the strip, the only waste material is in the small pieces punched out of the strip. Bands of greater length than those illustrated can be made conveniently by simply using wider metal strips and making the necessary adjustments of the dies and other tools that operate upon the strip.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

Claims

I claim:

1. A method of making hose clamps, comprising intermittently feeding forward a metal strip having a width equal to the length of each hose clamp band to be cut from it, punching groups of parallel slots in the strip in parallel rows extending transversely of the strip, the ends of said rows being spaced from the edges of the strip, stamping out the strip material between each edge of the strip and the adjacent ends of alternate rows of said slots to form a row of notches along each edge of the strip staggered relative to those along the opposite edge, the notches in each row being shaped to leave heads between them provided with lugs extending in opposite directions lengthwise of the strip, bending up said lugs, placing on each head an open-bottom screw housing having side flanges provided with openings receiving the head's lugs, bending the lugs down against said flanges to lock the housing on the head, feeding the strip ahead, and severing the strip transversely midway between the leading row of slots and the next succeeding row to form a hose clamp band with a screw housing at one end.

2. A method according to claim 1, in which each time the strip is fed forward it is moved a distance equal to the width of two hose clamp bands, and the strip also is severed midway between said next succeeding row of slots and the following row, whereby two hose clamp bands are cut from the strip simultaneously.

3. A method according to claim 1, including placing a tightening screw in each screw housing before the housing is applied to the underlying head.

4. A method according to claim 1, including punching rectangular openings in the strip in positions that will locate them in the centers of the heads.

5. A method according to claim 1, including first punching rectangular openings in the strip in positions that will locate them in the centers of the subsequently formed heads, placing a tightening screw in each screw housing before the housing is applied to the underlying head, the diameter of the screw being such that its thread will project down into the head opening, moving the strip forward a distance equal to twice the width of said band each time the strip is fed forward, and also severing the strip midway between said next succeeding row of slots and the following row, whereby to simultaneously cut two hose clamp bands from the strip.