Coiler spool with built-in gripper slot

A coiler spool comprises an elongated, hollow cylinder made of resilient spring steel and having a slot extending longitudinally of the cylinder, and means, such as an expandable mandrel, to radially expand the coiler spool to open the normally closed slot for reception in the open slot of a leading edge of a strip to be coiled. On release of the coiler spool expansion pressure, the coiler spool contracts due to its inherent resiliency and closes the slot, thereby gripping in the slot the leading edge of the strip to be coiled.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to the coiling of sheets and strip such as steel or 
other metal, and particularly to an elongated hollow, cylindrical coiler 
spool made of elastic material and having a longitudinally extending slot 
for reception and holding of the leading edge of a head end of a sheet or 
strip to be coiled. 
2. Description of the Prior Art 
In the coiling of metal sheet and strip (hereinafter called "strip"), it is 
common practice to use a belt wrapper, for example as shown and described 
in U.S. Pat. No. 3,315,510, to confine the strip as it is fed to a coiling 
mandrel to form a uniform coil. 
It also is known to provide a cylindrical drum or mandrel on which strip 
can be coiled and to provide such equipment with a longitudinal slot into 
which the leading edge of a strip to be coiled can be inserted to hold the 
head end of the strip while coiling. For example, U.S. Pat. Nos. 4,455,848 
and 4,485,651 disclose a rigid slotted, elongated cylindrical drum having 
a strip entry slot extending along the length of the drum for reception of 
a leading edge of the strip and which drum has an internal stop extending 
radially inwardly of the drum at a position opposite the slot and adapted 
to provide a tortuous path for the strip and providing frictional 
retaining engagement with the head end of the strip. U.S. Pat. No. 
3,122,337 discloses a rigid, cylindrical coiler drum provided with a 
longitudinal slot for reception of the leading edge of the strip to be 
coiled and having internal strengthening ribs to reinforce the rigidity of 
the drum, lugs to guide the advancing edge of the strip, and stops to 
terminate passage of the strip end inside the drum. 
U.S. Pat. No. 5,009,092 discloses a coiling apparatus including a rigid 
cylindrical coiling mandrel having a slotted opening for reception of the 
leading edge of a strip to be coiled. 
Each such apparatus is expensive and generally has the further drawback of 
inefficiently holding the leading edge of the strip in the rigid slot 
during the initial formation of the coil with the first few wraps. 
U.S. Pat. No. 3,433,355 relates to the production of rolls of adhesive tape 
wherein the tape is wound on an expanded core comprising radial segments 
separated by slots and which, on release of support for the core, collapse 
to form a unitary core supporting a coil of tape. 
SUMMARY OF THE INVENTION 
The coiler spool of the invention comprises an elongated hollow cylinder 
made of an elastic material, such as a suitable spring steel, and having a 
slot extending along the length of the spool and having a maximum width 
suitable for reception of the leading edge of a head end of an elongated 
strip, e.g. of steel or other metal, to be coiled. The elasticity 
properties of the coiler spool are such that, on expansion of the coiler 
spool under internal pressure, the slot is opened to receive the leading 
edge of the strip and, on release of the internal pressure on the spool, 
is automatically closed, thus tightly gripping the leading edge of the 
strip during coiling. The coiler spool is provided with an internal 
expandable mandrel of known type and construction, for example, either 
full face, stub or other type and either mechanically or hydraulically 
actuated, and adapted, on actuation, to expand into contact with the 
interior surface of the coiler spool, forcing open the slot and, on 
deactuation, to collapse, allowing the coiler spool automatically to 
contract, by its springlike action, to close the slot and grip the strip 
for coiling.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring to FIG. 1, the coiler spool 1 of the invention comprises an 
elongated, hollow cylinder provided with a longitudinally extending slot 2 
and may have a notch 3 in one end of the wall of the coiler spool. Coiler 
spool 1 is made of a resilient material, such as a suitable steel, for 
example, a high carbon, high strength spring steel, so that, on radial 
expansion of the cylinder, slot 2 is opened and, on release of the 
expansion pressure, the cylinder contracts to close slot 2. The coiler 
spool 1 is of sufficient length to accommodate the widest strip to be 
coiled, and has a suitable thickness, for example 1 inch, to efficiently 
utilize the resiliency of the spring steel and effectively to support the 
wraps of a coil wound thereon. 
As shown in FIGS. 2 and 3, an expandable mandrel 4 may be disposed inside 
coiler spool 1, the mandrel being fixed in location. and the coiler spool 
fitted thereover. Mandrel 4 is of conventional, full face, stub or other 
usual type and construction and, in the case of an hydraulically actuated 
mandrel, is connected to a source of pressurized fluid (not shown) for 
expanding the mandrel into contact with the interior wall of the coiler 
spool 1, as indicated by the arrows in FIGS. 2 and 3, and thereby 
expanding coiler spool 1 so that the slot 2 is opened for reception 
therein of a leading edge of a head end of a strip 6, as shown in FIG. 4. 
On release of pressure, mandrel 4 collapses, allowing coiler spool 1 
automatically to contract due to its inherent resiliency, and slot 2 to 
close, thus gripping the leading edge of the strip 6, as shown in FIG. 5. 
Thereafter strip 6, so held in position by the gripping action of coiler 
spool 1, can be coiled, as shown in FIG. 6. 
As above described, the coiler spool 1 may be provided with a notch 3 for 
interlocking with the mandrel 4 so that the mandrel will rotate with the 
coiler spool 1 during coiling. It it to be understood that notch 3 may be 
replaced with a protuberance or any other means which will provide the 
necessary interlocking relationship with the mandrel 4 for the purpose 
aforesaid. 
The improved coiler spool, as herein shown and described, provides an 
effective and low cost means to facilitate coiling of strip, replacing 
complicated and expensive coiling devices, such as belt wrappers.