Patent Publication Number: US-2023149963-A1

Title: Fire Protection Sprinkler Guard

Description:
PRIORITY CLAIM &amp; INCORPORATION BY REFERENCE 
     This application is a continuation application of U.S. patent application Ser. No. 17/615,656, filed Dec. 1, 2021, which is a 35 U.S.C. § 371 application of International Application No. PCT/US2020/037775, filed Jun. 15, 2020, which claims the benefit of U.S. Provisional Application No. 62/862,502 filed Jun. 17, 2019 each of which is incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to protection devices for fire protection sprinklers. More particularly, the present invention is directed to a sprinkler guard for protecting a sprinkler in its installed and operative position. 
     BACKGROUND OF THE INVENTION 
     Generally, automatic fire protection sprinklers include a frame for connection to a supply pipe of firefighting fluid and a deflection member coupled to the frame for distribution of the fluid to address a fire. The frame includes a formed body having an internal passageway with a fluid inlet for receipt of the fluid and a fluid outlet defining a discharge orifice from which the fluid is discharged. Externally formed about the sprinkler body proximate the outlet is a boss or enlarged formation for engagement by an installation tool such as a wrench to facilitate sprinkler installation. In an automatic sprinkler, the fluid discharge is automatically controlled by operation of a thermally responsive trigger or actuator that maintains a fluid tight seal at the discharge orifice by, for example, exertion of pressure on a sealing assembly disposed within the outlet. When the temperature surrounding the sprinkler is elevated within a range of the nominal temperature rating of the trigger, the trigger operates thereby permitting ejection and release of the sealing assembly and the discharge of fluid through the discharge orifice. The discharged fluid impacts the fluid deflection member and is distributed in a designed spray pattern and density in order to effectively address a fire and wet the surrounding area. Several factors can influence the water distribution patterns of a sprinkler including, for example, the installation orientation and the geometry of the fluid deflection member, the distance between the deflection member and the discharge orifice, and/or the shape of the sprinkler frame to which the deflection member is coupled. Accordingly, the fluid control, distribution and performance of an automatic sprinkler is dependent upon the integrity of the sprinkler assembly and its individual components. 
     Automatic sprinklers are installed in a variety of environments which can expose the sprinkler to accidental impact. For example, storage type automatic sprinklers can be installed in a storage warehouse beneath the warehouse ceiling and above the storage area and commodities to be protected. In the storage environment, stored commodities are stacked and moved by operating personnel or material handling equipment such as forklifts. The movement of material or mechanical equipment proximate to an installed automatic sprinkler exposes the sprinkler to possible accidental impact and damage. If the trigger of the sprinkler is damaged, water may discharge from the sprinkler; or if the deflector or frame is damaged, the sprinkler may not distribute fluid in the proper pattern. 
     It is well known to use a sprinkler guard to protect an installed sprinkler. Generally, the sprinkler guard includes a caged enclosure with one open-ended base. The guard is installed by sliding the guard over the sprinkler through the base so that the sprinkler is coaxially centered within the cage. The guard is affixed to the sprinkler by securing the open-ended base about the sprinkler body against the enlarged boss of the sprinkler body. Sprinkler guards are configured for protecting sprinklers installed in an upright orientation, in which fluid is discharged from the sprinkler body toward the ceiling and then redirected downward by the fluid deflection member toward the protection area or a pendent orientation. Sprinkler guards are also configured for protecting sprinklers installed in a pendent orientation, in which fluid is discharged downward to impact the fluid deflection member for distribution below the sprinkler over the protection area. In the case of suppression type sprinklers such as, for example, Early Suppression Fast Response (ESFR) fire protection sprinklers, a portion of the spray pattern is directed or thrusted axially downward below the sprinkler toward the area being protected. Illustrative examples of these known sprinkler guards are shown and described in U.S. Pat. Nos. 3,797,746; 5,632,339; and 5,893,418. Examples of commercially available sprinkler guards are shown and described in technical data publication  TFP 784:  Model EG -25  Sprinkler Guard For Model ESFR -25  Pendent Sprinkler  (December 2017) from Tyco Fire Products, LP and technical data publication Form F_012798: Sprinkler Guards (Oct. 11, 2018, Rev. 16.1) from Viking Corp. 
     Although these caged enclosures can protect a sprinkler, a design concern remains in ensuring that the cage structure itself does not interfere with or inhibit the fluid distribution performance of the sprinkler. This can be of particular concern where the cage structure or portion thereof is in the spray path directly below or proximate the sprinkler fluid deflection member. Accordingly, there remains a need for sprinkler guard structures that provide sufficient protection to a sprinkler while minimizing or eliminating interference with the spray pattern of the sprinkler. In addition, some of these known sprinkler guards present an installation complexity. More specifically, due to the single open end of the guard through which the sprinkler is inserted, there is limited flexibility when installing the guard about the sprinkler. This can be difficult when working around the surrounding pipe. In addition, some of these known guards use a sliding clip or ring to secure the guard about the sprinkler and require a specific installation tool which can add to the complexity in affixing the sprinkler guard to the sprinkler. Other known sprinkler guards, as seen for example in U.S. Pat. No. 1,469,336 use a hinged base at the open end of a wire sprinkler guard to secure the guard to the sprinkler body. Although the hinged base can swing open and closed about the sprinkler body, locating the sprinkler centrally within the guard still requires insertion of the sprinkler through the open end of the wire guard. Accordingly, there remains a need for a sprinkler guard that provides for a simplified and flexible manner of installation. 
     SUMMARY OF THE INVENTION 
     Preferred devices and methods to protect fire protection sprinklers are provided. Preferred embodiments of a fire protection sprinkler guard include a cylindrical structure with two guard portions in a hinged arrangement. The preferred hinge configuration of the sprinkler guard operates to flexibly receive a fire protection sprinkler. The hinged sprinkler guard defines an open state for receipt of the fire protection sprinkler and a closed state for surrounding and guarding the fire protection sprinkler. One preferred embodiment of the sprinkler guard includes a first guard portion having a first end and a second end axially spaced from one another with a first end plate disposed at the first end and a first grid of wire members affixed to the first end plate. A preferred second guard portion of the preferred sprinkler guard has a first end and a second end axially spaced from one another with a second end plate disposed at the first end of the second guard portion and a second grid of wire members affixed to the second end plate. The preferred sprinkler guard includes a hinged connection between the first guard portion and the second guard portion to pivot the first and second guard portions with respect to one another and define an open state of the sprinkler guard for receipt of the fire protection sprinkler and a closed state of the sprinkler guard to form a cage structure with a central guard axis for surrounding and guarding the fire protection sprinkler. 
     Preferred embodiments of the sprinkler guard include a latched configuration that operates in combination with the hinge of the guard to form a rigid cage structure to shield and protect the sprinkler from lateral impact. Additionally, preferred embodiments of the guard are configured for pendent-type fire protection sprinklers. The preferred sprinkler guard includes an open end that circumscribes the sprinkler proximate its fluid deflection member leaving the path below the sprinkler unimpeded so as to minimize or eliminate interference with the fluid distribution spray pattern of the protected sprinkler. 
     A preferred embodiment of a sprinkler guard having a central guard axis includes a first guard portion having a first end, a second end axially spaced from one another and a first end plate disposed at the first end. A second guard portion has a first end, a second end axially spaced from one another and a second end plate disposed at the first end. A preferred plurality of hinged connections between the first and second guard portions are axially aligned with one another, radially spaced from and extending parallel to the central guard axis. The plurality of hinged connections defines an open state of the sprinkler guard for receipt of a fire protection sprinkler and a closed state of the sprinkler guard for surrounding and guarding the fire protection sprinkler. In a closed state of the sprinkler guard, the first ends of the first and second guard portions circumscribe the central guard axis to define a first end of the sprinkler guard with the first and second end plates disposed for cooperatively engaging a body of the fire protection sprinkler. The second ends of the first and second guard portions circumscribe the central guard axis in the closed state of the guard to define a second end of the guard axially spaced from the first end of the guard portions. 
     Another preferred embodiment of a sprinkler guard includes a first guard portion having a first end, a second end axially spaced from one another and a plurality of eyelets axially aligned with one another between the first and second ends of the first guard portion. The preferred guard also includes a second guard portion having a first end, a second end axially spaced from one another and a plurality of pins axially aligned with one another between the first and second ends of the second guard portion. In the preferred guard a plurality of hinged connections between the first and second guard portions are defined by each of the plurality of eyelets being engaged by one of the plurality of pins. The plurality of hinged connections are preferably axially aligned with one another, radially spaced from and extending parallel to the central guard axis, the plurality of hinged connections defining an open state of the sprinkler guard for receipt of a fire protection sprinkler and a closed state of the sprinkler guard for surrounding and guarding the fire protection sprinkler. In the closed state of the sprinkler guard, the first ends of the first and second guard portions circumscribe the central guard axis to define a first end of the sprinkler guard, and the second ends of the first and second guard portions circumscribing the central guard axis to define a second end of the guard axially spaced from the first end of the guard. Other preferred embodiments of the sprinkler guard include a plurality of latch connections in which another plurality of eyelets is engaged by a plurality of latch pins. The latch connections preferably form a frictional engagement such that the closed state of the sprinkler guard forms a rigid structure. 
     Preferred methods of protecting a fire protection sprinkler include obtaining or providing a sprinkler guard having a first guard portion and a second guard portion with each guard portion having a first end with an end plate and grid of wire members affixed to the end plate. The preferred methods include pivoting the first and second guard portions with respect to one another between an open state of the sprinkler guard for receipt of the fire protection sprinkler and a closed state of the sprinkler guard for forming a cage structure with a central guard axis for surrounding and guarding the fire protection sprinkler. A preferred method of protecting a fire protection sprinkler includes obtaining a sprinkler guard that includes a first end, a second end and a plurality of hinge connections axially aligned with one another between the first and second ends that operate to define an open state of the sprinkler guard and a closed state of the sprinkler guard. The preferred method also includes providing the sprinkler guard to protect an installed fire protection sprinkler. 
     Preferred embodiments of the sprinkler guard provide for a simplified and flexible structure for installation about a fire protection sprinkler. Preferred embodiments of the sprinkler guard include a first end and a second end axially spaced from one another along a central guard axis. The preferred guard defines an internal space between the first and second end for housing the fire protection sprinkler; and a hinged connection between the first and second ends for operation along a pivot axis radially spaced and parallel to the central guard axis such that each of the first and second ends of the guard hinge open about the pivot axis to receive the fire protection sprinkler. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate exemplary embodiments of the invention, and together, with the general description given above and the detailed description given below, serve to explain the features of the invention. It should be understood that the preferred embodiments are some examples of the invention as provided by the appended claims. 
         FIG.  1    is a schematic exploded perspective view of a preferred embodiment of a sprinkler guard to protect an installed fire protection sprinkler. 
         FIG.  2    is an exploded view of the sprinkler guard of  FIG.  1   . 
         FIG.  3 A  is one guard portion for use in the sprinkler guard of  FIG.  1   . 
         FIG.  3 B  is another guard portion for use with the guard portion of  FIG.  3 A  and the sprinkler guard of  FIG.  1   . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Shown in  FIG.  1    is a preferred embodiment of a sprinkler guard  10  for the protection of a fire protection sprinkler, such as for example, sprinkler  100 . The sprinkler guard  10  has a first end  12  and a second end  14  axially spaced from the first end  12  along a central guard axis X-X. Preferred embodiments of the guard  10  define an internal space between the first and second ends  12 ,  14  for housing the fire protection sprinkler; and a hinged arrangement between the first and second ends  12 ,  14  such that each of the first and second ends  12 ,  14  of the guard hinge open to receive the fire protection sprinkler into the internal space and hinge close to enclose the sprinkler. The guard  10  is preferably a cylindrical structure and more preferably a substantially circular cylindrical structure with two or more guard portions  10   a ,  10   b  in a hinged arrangement. More preferably, the guard  10  includes two guard portions  10   a ,  10   b  in the hinged arrangement that pivot with respect to one another about a pivot axis H-H that extends parallel to the central guard axis X-X. As shown, the preferred guard  10  is hinged axially from the first end  12  to the second end  14  with a hinged connection  16 , and more preferably a group of hinge connections  16 , operating about the hinge axis H-H to pivot the two guard portions with respect to one another. The preferred hinge configuration operates to flexibly receive the sprinkler  100  which may be installed in an operative condition affixed to a fluid supply pipe FP, as schematically shown, that is filled with a firefighting fluid under fluid pressure. The hinged connections  16  individually and collectively define an open state of the guard  10  for receipt of the fire protection sprinkler  100  and a closed state for surrounding and guarding the fire protection sprinkler  100 . In addition, the preferred sprinkler guard  10  includes a latched configuration in which a latch  18 , more preferably a group of latches  18 , operate in combination with the preferred hinge connections  16  to surround and enclose the sprinkler  100  within the guard  10  and form a preferably rigid cage structure to shield and protect the sprinkler  100  from lateral impact. The guard  10  can define an alternate geometry such as, for example conical, provided the conical guard can provide for the hinged operation to define the closed and open states of the sprinkler. 
     In the closed configuration of the sprinkler guard  10  about the sprinkler  100 , the first end  12  of the sprinkler guard  10  is preferably configured to engage the sprinkler frame  110  in a manner that centers the sprinkler  100  within the guard  10  and substantially coaxially aligns the sprinkler axis S-S with the guard axis X-X. The second end  14  of the guard  10  is preferably open ended with the second end  14  preferably configured to circumscribe the fluid deflection member  120  of the sprinkler  100  thereby minimizing or eliminating interference with the spray coming off the deflection member  120  upon actuation of the sprinkler  100 . 
     Generally, the hinge connection  16  between the guard portions  10   a,    10   b  are provided by respective interlocking elements of the guard portions  10   a,    10   b.  Shown in  FIG.  2    is an exploded view of the preferred sprinkler guard  10  and its two portions  10   a,    10   b.  The first guard portion  10   a  has a first end  12   a  and a second end  14   a  axially spaced from the first end  12   a.  A group of closed loop formations or eyelets  20  are preferably axially aligned with one another between the first and second ends  12   a,    14   a  of the first guard portion  10   a.  The second guard portion  10   b  has a first end  12   b  and a second end  14   b  axially spaced from one another. The second guard portion  10   b  preferably includes a group of peg formations or pins  22  that are axially aligned with one another between the first and second ends  12   b,    14   b  of the second guard portion  10   b.  In the preferred embodiment of the sprinkler guard assembly  10  shown, each of the eyelets  20  is engaged by one of the plurality of pins  22  to form the preferred hinged connections  16  of the guard  10 . The hinged connections  16  are radially spaced from and extend parallel to the central guard axis X-X. 
     A preferred embodiment of the pin  22  is preferably elongated and oriented to extend along the hinge axis H-H parallel to the guard central axis X-X. In a preferred aspect, each of the pins  22  includes a base  22   a  that is affixed and more preferably integrally formed with the rest of the second guard portion  10   b.  Each pin  22  preferably includes a free end  22   b  opposite the base  22   a  to engage a corresponding eyelet  20  of the first guard portion  10   a.  In addition, the pins  22  are preferably oriented with the free end  22   b  above the base  22   a.  The eyelets  20  of the first guard portion  10   a  are preferably formed and oriented such that the geometric opening and center of the eyelets  20  are aligned to circumscribe the hinge axis H-H for coaxial receipt of the elongate pins. The interlocking elements  20 ,  22  can define alternative configurations provided the interlocking elements can provide a hinge connection as described herein. The pin  22  can include one or more bends, for example as shown in phantom in the hinge connection  16  of  FIG.  1   , with the free end  22   b  bent perpendicular to the remainder of the pin  22 . Further in the alternative, instead of the linear pin received in an eyelet, the interlocking elements can include two non-linear elements engaged with one another to form hinged rotation about a hinge axis H-H. 
     Dimensionally, the preferred pins  22  are preferably narrower than the openings defined by the respective eyelets  20 . Moreover, the pins  22  define a preferred axial length between the base  22   a  and free end  22   b  that is greater than the axial height or thickness of the eyelets  20 . The dimensional differences between the preferred pins  22  and the eyelets  20  and their respective orientations provide for flexibility in assembly and operation of the guard  10 . Each of the first and second guard portions  10   a,    10   b  are formed and fabricated from wire and more preferably from cold drawn steel wire. A preferred gauge (A.S.W) of the wire ranges from 7-10 of which the wire diameter can range from 0.125 inch to 0.177 inch. Accordingly, the pins  22  have a preferred diameter that ranges from 0.125 inch to 0.177 inch and the pins  22  are preferably formed to axial length of about ½ inch, preferably ranging from 0.45 inch to 0.5 inch. The wire is preferably looped to form the eyelets  20  with an eyelet width or internal diameter that preferably ranges from 0.15 inch to 0.18 inch with the axial thickness equivalent to that of the wire ranging from 0.125 inch to 0.177 inch. In preferred embodiments of the guard  10 , the ratio of external diameter-to-internal diameter ranging from 1.03:1 to 1.5:1. In another preferred aspect, the ratio of pin length-to-eyelet axial thickness ranges from 4:1 to 3:1. 
     In assembling the preferred sprinkler guard  10 , the eyelets  20  slide over the pins  22  in a downward direction under the force of gravity and are vertically restrained by the base  22   a.  With the pins  22  of the second guard portion  10   b  being of a diameter that is less than that of the receiving eyelets  20  of the first guard portion  10   a,  the two guard portions  10   a,    10   b  can freely rotate with respect to one another about the hinge axis H-H with minimal to no binding. This flexibility in the hinge operation can facilitate installation of the guard  10  about an installed sprinkler as described herein. 
     The preferred wire construction of each of the first and second guard portions  10   a ,  10   b  form one half of the cage sprinkler guard  10 . In preferred embodiments, each of the first and second guard portions  10   a,    10   b  include a grid of wire members including at least two vertical members  24   a,    24   b  extending parallel to the guard axis X-X and a group of arcuate members  26   a,    26   b  interconnecting the at least two vertical members  24   a,    24   b.  The wire members  24 ,  26  are preferably affixed to one another by appropriate means including, for example, spot welding. The arcuate members  26  are preferably disposed perpendicular to the adjoining vertical members so that each arcuate member  26  partially circumscribes the sprinkler guard axis X-X and more preferably spans 180 degrees about the guard axis. In each of the first and second guard portions  10   a,    10   b,  the arcuate members  26   a,    26   b  preferably define a common radius of curvature so that in the closed state of the guard  10 , the arcuate members  26   a,    26   b  define the preferred cylindrical bounds of the guard  10 . In the preferred formation of the hinge connections  16 , one or more of the arcuate members  26   a  of the first guard portion  10   a  have one end configured with the preferred eyelet  20 . In one or more of the arcuate members  26   b  of the second guard portion  10   b,  one end is configured with the preferred pin  22  for engagement with an eyelet  20  of the first guard portion  10   a  to form the preferred hinged connections  16 . 
     With the hinge connections  16  formed, the sprinkler guard  10  can operate between its open and closed states. In a preferred aspect of the guard  10 , the first and second guard portions  10   a,    10   b  form a preferred frictional engagement that renders the first guard portion  10   a  rigidly affixed with respect to the second portion  10   b  in the closed state of the guard  10 . With reference to  FIG.  1   , preferred embodiments of the sprinkler guard  10  include a latch and more preferably a group of latch connections  18  diametrically opposed to the hinge connections  16  to join the first and second guard portion  10   a,    10   b  and provide a rigidity to the guard structure. The plurality of latch connections  18  of the guard  10  are preferably axially aligned with one another parallel to the guard axis X-X diametrically opposite the hinged connections  16 . Preferably, the latch connections  18  are formed by an engagement between a second set of pin members  30  and eyelets  32 . Referring again to  FIG.  2   , two or more of the arcuate members  26   a  of the first guard portion  10   a  are configured with a preferred latch pin  30  at the end opposite the eyelet  20 . In two or more of the arcuate members  26   b  of the second guard portion  10   b,  the end opposite the pin  22  is configured with an eyelet  32  for engagement with one of the latch pins  30  of the first guard portion  10   a  to form the latch connections  18 . Alternatively, the parts can be reversed with the eyelets  32  formed on the arcuate members of the first guard portion  10   a  and the latch pins formed on the second guard portion  10   b.  Moreover, the latch connections  18  can be formed by differently configured interlocking members provided the resulting latch connection joins the two guard portions  10   a,    10   b  together so at to securely maintain the sprinkler guard  10  in the closed state. 
     With reference to  FIG.  3 B , in the first guard portion  10   a,  each latch pin  30  is preferably elongated and oriented to be skewed and more preferably orthogonal with respect to the hinge axis H-H and the central guard axis X-X. In a preferred aspect, each of the latch pins  30  includes a base  30   a  that is affixed and more preferably integrally formed with the rest of the preferred arcuate member  26   a.  Each latch pin  30  includes a free end  30   b  opposite the base  30   a  to engage a corresponding eyelet  32  of the second guard portion  10   a.  In addition, the latch pins  30  are preferably radially located at a radial distance RR from the hinge axis H-H so that the latch pins  30  form a frictional engagement with the eyelets  32 . The eyelets  32  of the second guard portion  10   b,  shown in  FIG.  3 A , are preferably formed and oriented such that the geometric opening of the eyelet  32  is sufficiently exposed to the free end  30   b  of the latch pin  30  to receive the latch pins  30  and form the preferred frictional engagement. Dimensionally, the latch pins  30  are preferably narrower than the openings defined by the respective eyelets  32  to form the latch connections  18 . Upon receipt within the eyelet  32 , the latch pin is preferably axially offset so as to contact the inner surface of the eyelet and form the preferred frictional engagement. Alternatively or additionally, the latch pin  30  can contact or rest against the bottom or lowest point along the inner surface of the eyelet. In one preferred embodiment, the radial distance RRR of the latch eyelet  32  from the hinge axis H-H, shown in  FIG.  3 A , is greater that the radial distance RR between the latch pin  30  and the hinge axis H-H, shown in  FIG.  3 B . By forming a frictional engagement, the first and second guard portions  10   a,    10   b  become rigidly engaged with respect to one another in the closed configuration of the sprinkler guard  10 . The preferred latch connections  18  can be used with alternate hinge configurations  16 . For example, the preferred latch connections  18  can be used with a single hinge connection  16  located diametrically opposed to the latch connections  18  to provide a rigid closed configuration of the sprinkler guard  10 . 
     With reference to  FIG.  1   , the first and second guard portions  10   a,    10   b  respectively include a first end plate  36   a  and a second end plate  36   b  at their respective first ends  12  for cooperatively engaging the sprinkler frame  110  in the closed state of the sprinkler guard  10 . Generally, the end plates  36   a,    36   b  together circumscribe the central guard axis X-X to form a centralized opening through which the sprinkler body protrudes for connection to a fluid supply pipe. The end plates  36   a,    36   b  are preferably affixed to respective vertical members  24  of the first and second guard portions so that the substantially planar end plates are disposed generally perpendicular to the central axis X-X. 
     The end plates  36   a,    36   b  cooperate with one another to form one or more of a hinged connection  38  or a latch connection  40 . In a preferred embodiment, the end plates include a hinged connection  38  axially aligned with the hinge axis H-H and a latch connection  40  that is aligned with the latch connections  18  joining the first guard portion  10   a  to the second guard portion  10   b.  Each of the connections  38 ,  40  can be formed by joining axially aligned through holes formed in the end plates  36   a,    36   b  with an appropriate mechanical fastener such as, for example, a rivet, a threaded fastener or a bolt and nut assembly. The inclusion of a hinge connection  38  and a latch connection  40  adds stability to the overall guard assembly  10 . In particular, the hinge connection  38  adds another hinge connection at the first end  12  of the sprinkler guard  10  to stabilize the assembly during opening and closing operation of the guard. Moreover, in forming the preferred hinge connection  38 , a portion of the first end plate  36   a  and a portion of the second end plate  36   b  overlap one another to form a preferred sliding engagement between the end plates  36   a,    36   b.  In the preferred embodiments shown in  FIGS.  1  and  2   , the first end plate  36   a  includes a semi-circular shelf  39   a  that overlaps a correspondingly formed quarter circle formation  39   b  to engage the shelf  39   a  in a rotational surface engagement about the hinge axis H-H. In a preferred aspect, the amount of overlap between the end plates  36   a,    36   b  is preferably about 15%-20% of the surface area of any one of the end plates  36   a ,  36   b.    
     The latch connection  40  reinforces and adds rigidity to the closed state of the sprinkler guard  10 . In the preferred embodiment of the guard  10  shown in  FIGS.  1  and  2   , each of the end plates  36   a,    36   b  include an angled formation  41   a,    41   b  that mate and cooperate with one another to form the latch connection  40 . Each of the mating surfaces of the angled formations  41   a,    41   b  are defined by a length L extending radially to the guard axis X-X and a depth dd extending parallel to the guard axis X-X. The length L of the mating surface can be constant over the depth dd of the mating surface or alternately vary over the depth dd of the mating surface. When the mating surfaces of the angled formations  41   a,    41   b  join one another, the preferably cylindrical guard  10  defines a preferably substantially consistent internal diameter D over the height of the guard  10 . In a preferred aspect, the length L of the mating surfaces define a preferred ratio with respect to the internal diameter D in which the ratio of the internal diameter D-to-length L of the mating surface (D:L) preferably ranges 5:1 to 6:1. 
     Each of the end plates  36   a,    36   b  include surfaces between the hinge connection  38  and the latch connection  40  that define the central opening in the closed state of the sprinkler guard  10  through which the sprinkler protrudes for connection to a fluid supply pipe. In the closed state of the guard  10 , the end plate surfaces contact the sprinkler frame to securely support and coaxially center the sprinkler within the guard and prevent its rotation therein. The supporting surfaces of the end plates  36   a,    36   b  can include a combination of linear edges, arcuate edges and planar surfaces that contact complimentary surfaces of the sprinkler frame to form a supporting surface engagement. In the closed state of the sprinkler guard  10 , each of the end plates  36   a,    36   b  preferably have central arcuate edges that contact curved surfaces of the sprinkler body. Moreover, each of the end plates  36   a,    36   b  each preferably include planar tabs disposed about the arcuate edge that extend parallel to the guard axis X-X to contact flat surfaces of the sprinkler frame, for example, located at the wrench flat. 
     The second end  14  of the sprinkler guard  10  is preferably open ended with no guard structure crossing or traversing the circumscribed area of the second end  14 . In preferred embodiments of the sprinkler  100 , the second end  14  of the guard  10  consists of two cooperating arcuate members  26   a,    26   b  having one hinged connection  16  and a latch connection  18  joining the arcuate members  26   a,    26   b  to one another in the closed state of the guard  10 . By providing an open end at the second end  14  of the guard  10 , the guard structure avoids or minimizes disruption to the spray pattern from the protected sprinkler. 
     The sprinkler guard  10  is preferably configured for protection of a pendent-type sprinkler and preferably an installed suppression pendent-type sprinkler. With reference to  FIG.  1   , the pendent sprinkler  100  and its frame  110  includes a body  102  with a fluid inlet and discharge outlet. Fluid discharged from the body  102  impacts the fluid deflection member  120  to address a fire and/or wet the surrounding area. The sprinkler body  102  is configured for coupling to the supply pipe FP of firefighting fluid such as, for example, water in which the supply pipe is suspended below a ceiling of an area to be protected by the sprinkler  100 . The body  102  can include an external thread for connection to a pipe fitting P such as, for example, a tee-fitting or pipe nipple. The body  102  can alternatively be externally configured for connection to a pipe coupling, for example, a grooved coupling. The frame  110  shown includes a pair of frame arms  104  that extends from the body  102  to support the fluid deflection member  120  at a coaxial distance from the sprinkler body  102 . The sprinkler  100  can be configured as an automatic sprinkler with a thermally responsive trigger  106  disposed between the frame arms  104  and axially aligned along the sprinkler axis S-S. The trigger can be configured as a thermally responsive soldered mechanical assembly  106  or a frangible thermally responsive glass bulb. Upon thermal actuation of the trigger, a seal is ejected from the sprinkler outlet and firefighting fluid is discharged from the body  102  to impact the fluid deflection member  120  for distribution. The fluid deflection member  120  includes an arrangement of slots about the sprinkler axis S-S to define an angular arrangement of tines about the sprinkler axis S-S. Firefighting fluid delivered to the sprinkler body  102  at an operating pressure of the sprinkler  100  is distributed by the fluid deflection member to provide a sprinkler performance such as, for example, fire suppression or control. In the case of suppression fluid distribution, the firefighting fluid is thrust coaxially downward below the sprinkler from the fluid deflection member  120 . 
     To protect an installed pendent sprinkler  100 , the guard  10  is placed in an open state by operation of the hinge connections  16  and wrapped about the sprinkler  100 . The guard  10  is preferably oriented, as schematically shown in  FIG.  1   , about the sprinkler  100  so that the hinge connection  16  and latch connections  18  are aligned in a common plane with the frame arms  104 . To enclose the sprinkler  100 , the hinge connections  16  are operated to bring the first and second guard portions  10   a,    10   b  together about the sprinkler  100 . The end plates  36   a,    36   b  are preferably located between the sprinkler body  102  and frame arms  104  to coaxially align the central guard axis X-X with the sprinkler axis S-S leaving the sprinkler body  102  protruding outside the guard  10 . The first and second guard portions  10   a,    10   b  are drawn together to engage the preferred latch pins  30  with the eyelets  32  to form the latch connections  18  and provide a rigid guard assembly  10  about the sprinkler  100 . 
     With the sprinkler  100  enclosed, the preferably cage structure of the guard  10  protects the sprinkler frame  110 , the thermally responsive trigger and the fluid deflection member  120  while sufficiently exposing the trigger to the ambient environment to appropriately thermally respond to a fire and/or rise in temperature. The preferably cylindrical guard  10  had an internal diameter D that defines a preferred ratio with respect to the maximum width W of the sprinkler  100  in which the ratio of guard diameter D-to-maximum sprinkler width W (D:W) ranges from 1.4:1 to 1.5:1. The internal space of the guard  10  between the first end  12  and the second end  14  provides sufficient space for housing the operational components of the sprinkler such as, for example, as its thermal trigger to operate and clear the fluid discharge path from the body to the fluid deflection member. In a preferred embodiment, the internal diameter of the closed configuration of the sprinkler guard  10  preferably ranges from 2⅞ inch to 3 inches. The maximum sprinkler width W can be defined by the outer surfaces of the frame arms  104 , as illustrated in  FIG.  1   , or alternatively, the maximum sprinkler diameter W can be defined by the fluid deflection member  120 . 
     In addition, the preferably open second end  14  of the guard  10  defines a preferably unobstructed area axially below the fluid deflection member  120  of the pendent sprinkler  100 . With no guard structure in the fluid deflection path of the sprinkler  100 , the spray pattern of the sprinkler  100  is unimpeded. Accordingly, for a suppression type pendent sprinkler, in which a component of the fluid spray is thrust axially downward, the preferred open end  14  of the sprinkler guard  10  is desirable. Moreover, to maximize the efficiency of fluid distribution of the protected sprinkler, the guard  10  can be configured so as to locate the fluid deflection member  120  with respect to the wire members forming the guard  10 . In a preferred aspect of the guard  10 , the engagement with the sprinkler  100  preferably axially locates the fluid deflection member between the axially spaced arcuate members  26 . With reference to  FIG.  3   , either one or both of the height YY 1  of the guard  10 , as defined by the vertical members  24 , and the axial spacing YY 2  between the arcuate members  26 , is preferably configured so as to locate the fluid deflection member  120  between the axially spaced arcuate members  26 . In one preferred embodiment, the height of the guard YY 1  is preferably greater than the axial distance Y in the sprinkler  100  defined between the end of the external threads of the body  102  and the fluid deflection member  120  as seen in  FIG.  1    so as to locate the fluid deflection member  120  between the axially spaced arcuate members  26 . 
     Embodiments of the sprinkler guard  10  provide preferred methods of protecting a fire protection sprinkler. For example, a preferred method includes obtaining a sprinkler guard  10 , as described herein, in which the guard  10  has a first end, a second end and a plurality of hinge connections axially aligned with one another between the first and second ends that operate to define an open state of the sprinkler guard and a closed state of the sprinkler guard. The preferred method further includes providing the sprinkler guard to protect an installed fire protection sprinkler. Obtaining the preferred sprinkler guard  10  can include manufacturing, fabricating or purchasing the guard  10  and preferably providing the guard  10  can include supplying and/or selling the guard  10 . 
     While the present invention has been disclosed with reference to certain embodiments, numerous modifications, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the present invention, as defined in the appended claims. Accordingly, it is intended that the present invention not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof.