Fire protection sprinkler head with spaced zones for mounting a protective guard and for connecting the sprinkler head to a water supply line

A sprinkler head comprises a tubular body having a first threaded end to be connected to a water line and having a second end that defines an outlet enclosed by a cap. A thermally responsive element, such as a glass bulb or heat fusible element, is engaged with the cap to maintain the cap in a closed position. The body is provided with a pair of generally parallel circumferential grooves. The bottom of one of the grooves adjacent the threaded end has a polygonal cross section to receive a wrench to enable the sprinkler head to be threadedly attached to a water line, while the other of the grooves receives the base portion of a wire-form protective guard that encloses the thermally responsive element.

BACKGROUND OF THE INVENTION 
Sprinkler heads that depend from low ceilings or those mounted in storage 
racks in industrial or commercial establishments frequently include a 
wire-form protective guard, which prevents accidental damage to the 
thermally responsive element, such as a glass bulb or fusible element. 
In a typical installation, each sprinkler head is connected to the water 
system by threading the sprinkler head to the water line through use of a 
special wrench or tool that engages a polygonal-shaped ridge or groove on 
the body of the sprinkler head. After installation of the sprinkler head, 
the wire guard is then installed on the sprinkler head. The wire guard is 
typically connected to the sprinkler head by engaging the base of the 
guard with the wrench groove, and the guard is then locked to the body by 
fasteners such as screws, or other fastening means. 
The installation of the protective guards is very time consuming and labor 
intensive. Such labor intensity and time consumption may be amplified by 
the common practice of installing all of the sprinkler heads first and 
then returning later to each sprinkler location to install the wire form 
guard in a second operation. Each wire guard is composed of two or more 
components, and the workman is normally working in an awkward overhead 
position, or in the case of storage racks, in relatively inaccessible 
locations. As a storage rack in an industrial or commercial establishment 
may contain thousands of sprinkler heads, the installation of the 
protective guards constitutes a time consuming process which comprises a 
substantial portion of the overall cost of the sprinkler system. 
SUMMARY OF THE INVENTION 
The invention is directed to a sprinkler head having a pre-assembled wire 
guard which will not interfere with the normal installation of the 
sprinkler head with the water line. 
The sprinkler head includes a tubular body, one end of which is threaded to 
a water line, while the opposite end defines an outlet that is normally 
enclosed by a cap or closure. 
In the preferred form of the sprinkler head, the body also includes a pair 
of arms which are joined together at a junction, and a thermally 
responsive member, such as a glass bulb or fusible element, is connected 
between the junction and the cap, thus retaining the cap in a closed 
position. When the thermally responsive member is exposed to an elevated 
temperature, it will release, enabling the pressure of the water in the 
water line to dislodge the cap and the water will then be discharged into 
the building or other establishment in a conventional manner. 
In accordance with the invention, the body of the sprinkler head is 
provided with a pair of circumferentially extending zones which preferably 
take the form of external grooves. The bottom of the groove which is 
located adjacent the threaded end of the body is provided with a polygonal 
configuration, preferably hexagonal, and is adapted to receive a wrench or 
tool. Engagement of the tool with the groove enables the sprinkler head to 
be rotated to thread the sprinkler head to the water line. 
The base of a wire-form protective guard is secured within the second of 
the two grooves. The guard itself can be of conventional construction and 
includes a mechanism for locking the base portion within the second 
groove. 
With the invention, the guard is preassembled with the sprinkler head at 
the factory, and as the wire guard does not restrict access to the wrench 
groove, the guard can be retained in place while the sprinkler head is 
attached to the water line. This results in a substantial savings in time 
and labor, due to the fact that it is not necessary to install the 
protective guard after installation of the sprinkler head to the water 
line. This provides a substantial overall cost saving in the sprinkler 
system. 
Moreover, as the guard is attached to the sprinkler head at the factory, it 
will protect the thermally responsive element during shipment and handling 
of the sprinkler head. 
Other objects and advantages will appear during the course of the following 
description.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
FIG. 1 illustrates a sprinkler head including a body or frame 1 having an 
external thread 2 that is adapted to be connected to a water line. The 
opposite end of the tubular body 1 defines an outlet 3 which is normally 
sealed by a cap or closure 4. 
Body 1 also includes a pair of depending arms 5 and the outer ends of the 
arms are joined at a junction 6. As shown in FIG. 1, a thermally 
responsive member 7 interconnects the cap 4 and an adjusting screw 8 which 
is threaded within an opening in the junction 6. 
The thermally responsive member can take the form of a conventional glass 
bulb or alternately a fusible element. When the thermally responsive 
member is exposed to an elevated temperature, it will release, enabling 
the water pressure within the water line to dislodge cap 4. The water will 
then flow outwardly through outlet 3 and be deflected radially outward in 
a spray pattern by a deflector 9, which is carried by the junction 6. 
A wrench boss or groove 10 is formed in body 1 outward of the thread 2, and 
the bottom 11 of groove 10 has a non-circular, polygonal shape, preferably 
hexagonal. In addition to groove 10, a second circumferential groove 12 is 
formed outwardly of groove 10 and the bottom of groove 12 also can have a 
non-circular or polygonal configuration, such as hexagonal. 
Groove 10 serves to receive a conventional wrench or tool through which the 
sprinkler head can be threaded onto the water line, while groove 12 
receives a water permeable wire form protective guard 14. 
As shown in FIG. 2, guard 14 includes a pair of generally parallel base 
members 15, each of which is formed with a recess 16 which is adapted to 
engage opposite sides of the bottom of groove 12. 
A series of wire arms 17 are each provided with a bent foot 18, and each 
foot is attached to the respective base members 15. The outer ends of arms 
17 are bent radially inward as indicated by 19, and are joined together at 
a junction 20. 
To lock the guard to the body 1, a locking ring 21 is employed. By sliding 
the ring 21 inwardly over the arms 17, the arms will be deflected inwardly 
to bring the base members 15 into tight engagement with groove 12. Locking 
ring 21 is secured in position by engagement with detents or notches 22 
formed in the arms 17. 
When locked in position, guard 14 surrounds the thermally responsive member 
7 and serves to protect that member during shipment, storage, and usage. 
With the use of the double parallel grooves, the guard 14 can be installed 
at the factory by engaging the base members 15 with the groove 12. The 
second wrench groove 10 is accessible when the guard 14 is in place so 
that the sprinkler head can be threaded to the water line without removal 
of the guard. 
The invention thus eliminates the conventional task of having to install 
the guard 14 after the sprinkler head is attached to the water line. 
As previously noted, the task of connecting the protective guard, as 
required in the past, was time consuming, because the guard is normally 
composed of multiple components and the operator is required to work in an 
awkward overhead position, or in a relatively inaccessible location when 
dealing with storage racks, in order to install the guard. 
As the guard, as associated with the sprinkler head of the invention, is 
installed at the factory, it also serves to protect the thermally 
responsive member from damage during shipment and handling.