Method of shaping a screw type clamping collar

In accordance with the process of the present invention the flexible collar of a screw-type clamping collar is formed of a flexible metal strip of predetermined width, and one end thereof is either hot or cold stamped to force material of the collar outwardly along its edges at predetermined locations where transverse shoulders are desired to serve as stops for the clamp's saddle housing with sufficient rigidity and strength to withstand the pulling force applied to the clamping collar.

Referring now to the drawings in detail, and initially to FIG. 1 thereof, a 
screw-type clamping collar 10 constructed by use of the method of the 
present invention is illustrated which includes a flexible band 11, a 
saddle housing 12, and a screw 13. The latter is mounted in any known 
manner for free rotation inside housing 12, but is held by the housing in 
a fixed axial position. 
The saddle housing, with its screw 13, is mounted adjacent one end 14 of 
flexible band 11. The band has at its other end 16 a number of transverse 
openings 18 formed therein which define a gear rack that engages and 
cooperates with the threads of screw 13, when this end is engaged in the 
housing between the screw and the end 14 of the band. 
The flexible band or collar 11 is preferably formed of a malleable 
material, such as metal, with a uniform width L selected to be the width 
necessary for the use to which the clamp is to be placed. The length of 
the band is cut such that the band will make, after rolling, a collar 
having a specific diameter. 
In accordance with the present invention, the end 14 of the band is placed 
on an anvil or boss 16 which has longitudinal guiding tracks 18 formed in 
raised parts 20 thereon. The band rests on four bosses 22 formed in the 
base of the anvil. Each boss has a rectangular top surface in plan which 
slopes (as seen in FIG. 3) from a point near the median axis of the band 
downwardly and away from the band. Between the bosses, clearings or 
recesses 24 are formed in the anvil to enable the passage of tongs 26 
carried by a reciprocal punch head 28. 
As seen in FIG. 4, when punch head 28 is operated downwardly, in the line 
of arrow F, (as for example by a cam or the like in the conventional 
manner) the tongs or punches 26 penetrate into the anvil recesses 24 and 
the bottom 30 of the punch head engages the flexible band 11. The striking 
of the band in this manner pushes the malleable material of the band 
laterally in the direction of arrows f, to form the pairs of stops or 
shoulders 32 on the band. At the same time, the tongs 26 prevent the band 
material from flowing between these shoulders and thus form recesses 34 
therebetween (see FIG. 6). 
Additional operations may be performed on the band end 14 by cutting a 
central opening 36 therein forming a profiled end 38 as shown in FIG. 6. 
These operations can be performed in any known manner. 
The saddle housing 12, having screw 3 mounted therein is secured to the end 
14 of band 11 by its lugs 40 which are initially straight and placed 
between the respective pairs of shoulders 32 (see FIG. 6) until its own 
shoulders 42 engage the stops 32. The lugs are then turned or bent down 
under the band to complete the assembly (see FIG. 7). 
The flexible band 11 can also be shaped to form shoulders 32 by the 
apparatus illustrated in FIGS. 8 to 13. As seen therein the end 14 of band 
11 is placed and properly guided in guide tracks or the like on an anvil 
or base 44 having an opening 46 therein. A reciprocal punch-carrier 49 
having a punch 50 mounted thereon is guided in a pressure plate 52 above 
anvil 44. The carrier and plate are reciprocated in any known manner to 
cause the punch to cooperate with the anvil and punch or cut a median slot 
54 having bulged-out or rounded ends 56 in the median portions of band 11 
(see FIG. 9). The slotted band end is then placed and guided on a second 
anvil 58 having, underneath the positions at which the band is supported, 
two laterally movable parts 60 biased by springs 62. A second punch 
assembly incluidng a reciprocal punch carrier 64, a punch 66 and a 
pressure plate 68 are located above this second anvil and operation 
thereof against the anvil will cause the second punch 66, which is wider 
than punch 50, to penetrate slot 56 and move the anvil parts 60 apart from 
each other, against the bias of the springs thus forcing the band material 
to move adjacent slot 56 to form protuberances 64, while the conical punch 
66 expands slot 56 (see FIGS. 10 and 11). 
The end 14 of band 11 is then placed and guided on a third anvil 67 where 
it is held in place by a reciprocal pressure plate 68 in which three 
punches 70, 72, 74 are slidable. These punches are carried by a reciprocal 
punch-carrier 76. Upon operation or reciprocation of carrier 76 toward 
anvil 67 (which has complementary openings therein) the punches 72, 74 
form the desired shoulders 32 separated by recesses or spaces 24 (see 
FIGS. 12 and 13) and the punch 72 further widens slot 54. If desired the 
punch may be designed to also cut the end 16 of the band (see FIG. 13) to 
form a profiled end. 
According to another embodiment of the invention (shown in FIGS. 14, 15 and 
16) band 11 is, in a first operation, punched (in a process similar to 
that shown in FIG. 8) to form generally bow-tie shaped openings 80 therein 
in slightly spaced relation to each other (see FIG. 14). These openings 
have inwardly curved sides 81. The band is then punched again, between a 
punch and anvil (in the same manner as described above with respect to 
FIG. 10) in order to move the side edges of the band, forming lateral 
protrusions 82, while enlarging openings 86 (see FIG. 15). The inwardly 
curved sides 81 of the originally formed openings 80 provide the material 
in the band that allows protrusions to be formed without substantial 
reduction in the thickness of the band. The lateral protrusions are then 
punched again (in the same manner as described with respect to FIG. 12) in 
order to form transverse shoulders 84 with recesses 86 therebetween (see 
FIG. 16). 
From the above it is seen that by the present invention the collar or band 
is treated and shaped to form a strong and convenient mount for assembly 
of the saddle housing with the band. Moreover the process allows the 
flexible band to be formed initially only as wide as required for the 
completed collar. This results in a substantial savings of material as 
compared to previously proposed structures with a resulting reduction in 
manufacturing costs. The process is performed by a series of relatively 
simple operations on the band to achieve the desired shape; and the 
resulting transverse shoulders provide substantial strength in the final 
assembly at the critical point in the collar where stresses are 
transmitted from the saddle housing to the flexible band. 
Although illustrative embodiments of the present invention have been 
described herein with reference to the accompanying drawings it is to be 
understood that the invention is not limited to those precise embodiments 
thereof but that various changes and modifications may be effected therein 
by one skilled in the art without departing from the scope or spirit of 
this invention.