Hose clamp

A hose clamp is disclosed comprising a clamping band having open ends for lapping one end over the other end in a lapping direction and presenting a lapped portion and a lapping portion. The open ends of the band are mechanically interconnected by several outwardly extending hooks in the lapped portion. The hooks are operable to engage in corresponding apertures in the lapping portion. The clamp structure has an ear for tightening the clamping band about an object to be fastened, characterized in that at least one hook extends out of the plane in the lapping direction presenting a hook aperture and at least one corresponding aperture has a tab extending from an edge of the aperture in a direction opposite the lapping direction for abutting the hook, whereupon deformation of the ear the tab deforms towards the lapped portion forming an abutment surface for absorbing the circumferentially directed clamping forces and projects into the hook aperture for interlocking the lapped portion with the lapping portion.

FIELD OF INVENTION 
This invention relates to a hose clamp, more particularly to an open hose 
clamp having free ends adapted to be mechanically interconnected and 
having an ear to be deformed for reducing the circumference of the clamp 
to produce a clamping force. 
BACKGROUND OF INVENTION 
Various types of hose clamps are known in the prior art in which a clamping 
band made of flat strip material was adapted to be mechanically 
interconnected at the free ends thereof to form a ring-like clamping 
structure that can be tightened by contraction of so-called "Oetiker" ear 
as described in U.S. Pat. No. 3,789,463. 
In particular, U.S. Pat. No. 4,299,012 discloses a clamping band having 
open ends adapted to be mechanically interconnected by outwardly extending 
hooks in an inner band portion operable to engage in corresponding 
apertures provided in an outer band portion. The band is provided with a 
plastically deformable ear which is provided for tightening the clamping 
band about an object to be fastened by plastic deformation of the ear. 
This clamp provides a substantially gap-free transition in the 
circumferential direction from the inner band portion to the ring like 
configuration of the clamp structured defined by the clamping band by the 
use of a tongue like extension at the free end of the inner band portion 
which is operable to engage into a tongue receiving aperture or channel 
provided in the outer band portion. 
In order to provide the hooks of this type of clamp with sufficient 
strength to resist the tensional forces upon contracting the ear, the 
clamp is provided with at least one support hook which is realised by 
cold-deforming the band material to present a force engaging abutment 
surface to absorb the circumferentially directed forces. Although the cold 
deformed support hooks resist the circumferentially directed forces 
adequately, such support hooks do not adequately engage the aperture in 
the outer band member to maintain engagement therewith during crimping of 
the ear. As a result, the outer band member may dislodge from the inner 
band member during contraction of the ear resulting in the misclamping of 
the clamp about the objects to be clamped. This results in waste as the 
clamps cannot be reused after the ear has been deformed. 
A person installing a clamp could deform the ear in a manner known in the 
art until the outer band member on opposite sides of the ear contact each 
other for maximum clamping force. Other than maximum clamping where the 
ear is fully deformed, there is no way to determine accurately the degree 
of clamping force which has been applied to the hose. There is no reliable 
method for determining whether the clamp has been crimped to a sufficient 
degree. Quality control of the installation of such clamps is difficult, 
time consuming and requires a special skill to evaluate the crimp of the 
clamp. 
OBJECTS OF THE INVENTION 
It is an object of the invention to provide a clamp structure of the open 
type, which can be installed circumferentially about an object to be 
fastened and in which the open ends can be thereafter interconnected 
mechanically by the use of hooks and tabs which will deform upon crimping 
of the ear to positively engage the ends of the clamp structure. 
It is a further object of this invention to provide a clamping structure 
having a non load-bearing hook which extends from the lapped band to the 
lapping band through an aperture therein when the clamp has been crimped 
to a sufficient degree thereby limiting the degree of crimping. 
It is still a further object of this invention to provide the lapped end 
with an aperture extending circumferentially thereof for receiving a 
circumferentially extending projection extending towards the lapped end 
for maintaining the lapped end seated under the lapping end upon crimping 
of the ear. 
These and other objects may be accomplished by providing a clamping 
structure comprising a clamping band having open ends for lapping one end 
over the other end in a lapping direction and presenting a lapped portion 
and a lapping portion. The open ends of the band are mechanically 
interconnected by several outwardly extending hooks in the lapped portion. 
The hooks are operable to engage in corresponding apertures in the lapping 
portion. The clamp structure has an ear for tightening the clamping band 
about an object to be fastened, characterized in that at least one hook 
extends out of the plane in the lapping direction presenting a hook 
aperture and at least one corresponding aperture has a tab extending from 
an edge of the aperture in a direction opposite the lapping direction for 
abutting the hook, whereupon deformation of the ear the tab deforms 
towards the lapped portion forming an abutment surface for absorbing the 
circumferentially directed clamping forces and projects into the hook 
aperture for interlocking the lapped portion with the lapping portion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The clamp of the present invention is generally illustrated as 10 on FIG. 
1. Clamp 10 generally comprises a thin band of sheet metal, preferably 
stainless steel. 
Clamp 10 comprises a lapped end 12 and a lapping end 14. The direction 
moving from the lapped end 12 to the lapping end 14 defines a lapping 
direction as illustrated by the arrow on FIG. 1. 
Lapped end 12 is provided with an aperture 16 which extends 
circumferentially of the clamp 10. Next along the circumferential extent 
of the clamp 10 are hooks 18. Hooks 18 are lanced by cutting a 
substantially U-shaped cut through the clamp 10. The hooks are bent 
outwardly from the surface of the clamp 10 in a lapping direction to 
present hook apertures 19. 
Next along the clamp 10 there is provided a step 20 defining the limit 
between the lapped end 1 and the lapping end 14. 
Next along the clamp 10 is a dimple 22 formed by lansing two 
circumferentially extending slots and punching the metal between the two 
slots inwardly to form dimple 22. The distance between adjacent slots to 
form dimple 22 is less than the distance between the longitudinal edges of 
slot 16. Dimple 22 will extend into aperture 16, but is adapted not to 
extend beyond the thickness of the band. 
Next along the clamp 10 there is an ear 24 which includes generally 
outwardly extending leg portions 3 and 32 and interconnected by a bridging 
portion 36. Bridging portion 36 has an inwardly formed emboss 38. 
Next along clamp 10 there is provided a plurality of like apertures 26, in 
substantially circumferential alignment. Preferably, apertures 26 have a 
substantially square outline having a tab 28 extending from one edge 
thereof. Tabs 28 extend in a direction opposite the lapping direction. 
Hooks 18 are adapted to extend through aperture 26 and will abut tab 28 as 
illustrated in FIGS. 2 and 4. Alternatively, apertures 26 and tab 28 could 
have a U-shaped or circular outline as illustrated in FIG. 3a. 
In operation, the clamp is placed about an object to be clamped. For 
instance, the clamps of the present invention are commonly used to retain 
a flexible boot about a constant velocity joint which is commonly used for 
front wheel drive automobiles. 
The clamp 10 is placed about the object and the lapping end 14 is 
overlapped over the lapped end 12. In this position, hooks 18 will extend 
through two of apertures 26 and dimple formation 22 will extend into 
aperture 16. Ear 24 is contracted by applying a force at the base of legs 
30 and 32 until the opposite leg members contact each other. 
As ear 24 is deformed, dimple 22 will slide relative within aperture 16. 
The dimple 22 will retain the lapped 12 beneath the lapping end 14. 
As the ear 24 is contracted, the circumference of the clamp 10 is 
diminished causing tab 28 to abut firmly with hook 18. Upon further 
contraction of ear 24, tab 28 will deform inwardly as hook 18 deforms 
outwardly increasing the engagement between the lapped end and the lapping 
end. Upon completion of the crimping process, tab 28 will be fully 
registered within hook aperture 19 and hook 18 will overlap tab 28 to 
securely connect the open ends of clamp 10 together providing clamping 
forces to retaining the object about the object. 
In a second embodiment as illustrated in FIGS. 5, 6 and 7, the clamp 110 is 
identical to the clamp 10 except that clamp 110 has a single pair of hooks 
18 and corresponding apertures 26. Between ear 24 and dimple 22 there is 
provided an aperture 126 which has the same outline as aperture 26. On the 
lapped end 112 between the hooks 18 and aperture 16, hook 118 extends 
towards the lapping end 114, in a lapping direction. The base of hook 118 
and aperture 126 will be separated in a lapping direction by the final 
circumferential distance required for final clamping. 
In operation, the clamp 118 operates in the same fashion as the first 
embodiment. As clamp 118 is being crimped, hook 118 will abut with surface 
150 of the lapping end 114. Upon further crimping, the hook 118 will be 
deflected under the lapping end 114. Upon further crimping, hook 118 will 
travel past surface 150 until hook 118 springs through aperture 126. When 
hook 118 springs through aperture 126 the clamp has been crimped 
sufficiently within predetermined limits. 
Even after plastic deformation of the ear, there will still be a certain 
amount of elastic deformation. Therefore upon release of the crimping 
device from the ear, the clamp 110 will expand elastically due to the 
resiliency of the article being clamped. As the clamp 110 expands, hook 
118 will abut with tab 128 of aperture 126 and tab 128 will deform 
inwardly as hook 118 deforms outwardly increasing the engagement between 
the lapped end and the lapping end. 
As is apparent, the engagement of the lapped and lapping end by hook 118 
and aperture 126 provides the clamp with an additional means of 
securement. If the ear is severed, the hook 118 and aperture 126 will 
maintain the clamp about the object being clamped and maintaining a 
clamping force. For a boot being clamped to about a CV rod on an 
automobile, this increases the likelihood that a failed clamp will be 
detected upon routine inspection and maintenance of the automobile. 
It is also apparent to a worker skilled in the art that with a plurality of 
like hooks 118 or a plurality of like apertures 126 together with a 
plurality of apertures 26 the clamp could be adapted to have a plurality 
of fixed circumferential distances. Each aperture 126 could be coded or 
marked to indicate the final circumferential distance. 
Although the disclosure describes and illustrates preferred embodiments of 
the invention, it is to be understood that the invention is not limited to 
the particular embodiments. Many variations and modifications will now 
occur to those skilled in the art.