Fire Suppression Sprinkler and Deflector

Abstract

A sprinkler for a fire suppression system includes a deflector plate having five different types of slots extending from a periphery of the plate toward a center of the plate along radially extending lines. The slots are arrow shaped, club shaped and key hole shaped. Arrow head slots which align with frame arms supporting the deflector plate are wider than the thickness of the frame arms. Club shaped and arrow shaped slots proximate the plane of the frame arms are asymmetrical with respect to radial lines extending from the center of the plate, while arrow shaped and key hole shaped slots distal to the plane of the frame arms are symmetrical with respect to radial lines extending from the center of the plate.

Claims

1. A fire suppression sprinkler, said sprinkler comprising: a body surrounding a bore, said bore defining a flow axis arranged coaxially with said bore; first and second frame arms mounted on opposite sides of said body and extending therefrom in a direction along said flow axis, said frame arms defining a plane; a nose mounted on the ends of said frame arms, said nose being positioned coaxially with said flow axis; a deflector plate mounted on said nose and oriented transversely to said flow axis, said deflector plate having a periphery surrounding a center located on said flow axis, said deflector plate comprising: a plurality of slots of a first configuration extending from said periphery radially toward said center, at least two of said slots of said first configuration being disposed in said plane; at least four slots of a second configuration extending from said periphery radially toward said center and being located about said periphery such that one of said slots of said second configuration is positioned adjacent to each side of each of said slots of said first configuration which are disposed in said plane; a plurality of slots of a third configuration extending from said periphery radially toward said center; wherein said slots of said second configuration have a greater area than said slots of said first configuration.

2. The fire suppression sprinkler according to claim 1, wherein said slots of said second configuration have the greatest area of any of said slots of said first and said third configurations.

3. The fire suppression sprinkler according to claim 1, wherein said bore defines a k factor of k=14.0 or greater and wherein said fire suppression sprinkler is adapted to be installed in a pendent orientation.

4. The fire suppression sprinkler according to claim 1, wherein said slots of said second configuration have a club shape comprising a handle extending from said periphery and a club head terminating at a distance from said center, wherein a width of said club head proximate to said handle is less than a width of said club head proximate to said center.

5. The fire suppression sprinkler according to claim 4, wherein a widest width of said club head is wider than a widest width of said handle.

6. The fire suppression sprinkler according to claim 5, wherein said club head has a curved tip at said distance from said center.

7. The fire suppression sprinkler according to claim 4, wherein said club head is asymmetric with respect to a line extending radially from said center.

8. The fire suppression sprinkler according to claim 7, wherein said club head is defined by a first edge oriented at a first angle with respect to said line, and a second edge, opposite to said first edge, said second edge oriented at a second angle with respect to said line, said second angle being different from said first angle.

9. The fire suppression sprinkler according to claim 4, wherein each of said slots of said second configuration are symmetric with respect to a line extending radially from said center.

10. The fire suppression sprinkler of claim 1, where said slots of said second configuration have a keyhole shape comprising a waist extending from said periphery and a key head terminating at a distance from said center.

11. The fire suppression sprinkler according to claim 10, wherein a widest width of said key head is wider than a widest width of said waist.

12. The fire suppression sprinkler according to claim 10, wherein a width of said key head proximate to said waist is equal to a width of said key head proximate to said center.

13. The fire suppression sprinkler according to claim 10, wherein said key head has a curved tip at said distance from said center.

14. The fire suppression sprinkler according to claim 10, wherein said key head is symmetric with respect to a line extending radially from said center.

15. The fire suppression sprinkler of claim 1, where said slots of said first configuration have an arrowhead shape comprising a shaft extending from said periphery and an arrowhead terminating at a first distance from said center, wherein said arrowhead is asymmetric with respect to a line extending radially from said center.

16. The fire suppression sprinkler according to claim 15, wherein said arrowhead is defined by a first edge oriented at a first angle with respect to said line, and a second edge, opposite to said first edge, said second edge oriented at a second angle with respect to said line, said second angle being different from said first angle.

17. The fire suppression sprinkler according to claim 15, wherein a widest width of said arrowhead is wider than a widest width of said shaft.

18. The fire suppression sprinkler according to claim 15, wherein a width of said arrowhead proximate to said shaft is greater than a width of said arrowhead proximate to said center.

19. The fire suppression sprinkler according to claim 15, wherein said arrowhead has a curved tip at said distance from said center.

20. The fire suppression sprinkler according to claim 15, wherein said shaft has a width at said periphery which is greater than a width of said shaft proximate to said arrowhead.

21. The fire suppression sprinkler according to claim 15, wherein said shaft is defined by first and second oppositely disposed edges, each said edge being angularly oriented with respect to a line extending radially from said center such that said shaft has a width at said periphery which is greater than a width of said shaft proximate to said arrowhead

22. The fire suppression sprinkler of claim 1, wherein said deflector plate further comprises a plurality of slots of a fourth configuration.

23. The fire suppression sprinkler of claim 22, wherein said deflector plate further comprises a plurality of slots of a fifth configuration.

24. A fire suppression sprinkler, said sprinkler comprising: a body surrounding a bore, said bore defining a flow axis arranged coaxially with said bore; first and second frame arms mounted on opposite sides of said body and extending therefrom in a direction along said flow axis, said frame arms defining a plane; a nose mounted on the ends of said frame arms, said nose being positioned coaxially with said flow axis; a deflector plate mounted on said nose and oriented transversely to said flow axis, said deflector plate having a periphery surrounding a center located on said flow axis, said deflector plate comprising: a plurality of slots of a first configuration extending from said periphery radially toward said center and terminating at a first distance from said center, at least two of said slots of said first configuration being disposed in said plane; at least four slots of a second configuration extending from said periphery radially toward said center and terminating at a second distance from said center, said slots of said second configuration being located about said periphery such that one of said slots of said second configuration is positioned adjacent to each side of each of said slots of said first configuration which are disposed in said plane; a plurality of slots of a third configuration extending from said periphery radially toward said center and terminating at a third distance from said center; wherein said second distance is less than any of said first or third distances.

25. The fire suppression sprinkler of claim 24, where said nose has a maximum radius measured from said flow axis, said first, second, and third distances being greater than said maximum radius.

26. The fire suppression sprinkler according to claim 24, wherein said bore defines a k factor of k=14.0 or greater and wherein said fire suppression sprinkler is adapted to be installed in a pendent orientation.

27. The fire suppression sprinkler according to claim 24, wherein said slots of said second configuration have a club shape comprising a handle extending from said periphery and a club head terminating at a distance from said center, wherein a width of said club head proximate to said handle is less than a width of said club head proximate to said center.

28. The fire suppression sprinkler according to claim 27, wherein a widest width of said club head is wider than a widest width of said handle.

29. The fire suppression sprinkler according to claim 28, wherein said club head has a curved tip at said distance from said center.

30. The fire suppression sprinkler according to claim 27, wherein said club head is asymmetric with respect to a line extending radially from said center.

31. The fire suppression sprinkler according to claim 30, wherein said club head is defined by a first edge oriented at a first angle with respect to said line, and a second edge, opposite to said first edge, said second edge oriented at a second angle with respect to said line, said second angle being different from said first angle.

32. The fire suppression sprinkler according to claim 27, wherein each of said slots of said second configuration are symmetric with respect to a line extending radially from said center.

33. The fire suppression sprinkler of claim 24, where said slots of said second configuration have a keyhole shape comprising a waist extending from said periphery and a key head terminating at a distance from said center.

34. The fire suppression sprinkler according to claim 33, wherein a widest width of said key head is wider than a widest width of said waist.

35. The fire suppression sprinkler according to claim 33, wherein a width of said key head proximate to said waist is equal to a width of said key head proximate to said center.

36. The fire suppression sprinkler according to claim 33, wherein said key head has a curved tip at said distance from said center.

37. The fire suppression sprinkler according to claim 33, wherein said key head is symmetric with respect to a line extending radially from said center.

38. The fire suppression sprinkler of claim 24, where said slots of said first configuration have an arrowhead shape comprising a shaft extending from said periphery and an arrowhead terminating at a first distance from said center, wherein said arrowhead is asymmetric with respect to a line extending radially from said center.

39. The fire suppression sprinkler according to claim 38, wherein said arrowhead is defined by a first edge oriented at a first angle with respect to said line, and a second edge, opposite to said first edge, said second edge oriented at a second angle with respect to said line, said second angle being different from said first angle.

40. The fire suppression sprinkler according to claim 38, wherein a widest width of said arrowhead is wider than a widest width of said shaft.

41. The fire suppression sprinkler according to claim 38, wherein a width of said arrowhead proximate to said shaft is greater than a width of said arrowhead proximate to said center.

42. The fire suppression sprinkler according to claim 38, wherein said arrowhead has a curved tip at said distance from said center.

43. The fire suppression sprinkler according to claim 38, wherein said shaft has a width at said periphery which is greater than a width of said shaft proximate to said arrowhead.

44. The fire suppression sprinkler according to claim 38, wherein said shaft is defined by first and second oppositely disposed edges, each said edge being angularly oriented with respect to a line extending radially from said center such that said shaft has a width at said periphery which is greater than a width of said shaft proximate to said arrowhead.

45. The fire suppression sprinkler of claim 24, wherein said deflector plate further comprises a plurality of slots of a fourth configuration.

46. The fire suppression sprinkler of claim 45, wherein said deflector plate further comprises a plurality of slots of a fifth configuration.

47. An early suppression fast response fire suppression sprinkler, said sprinkler comprising: a body adapted for use in a pendent orientation, said body surrounding a bore, said bore defining a flow axis arranged coaxially with said bore, said bore defining a k factor of k=25.2 or greater; first and second frame arms mounted on opposite sides of said body and extending therefrom in a direction along said flow axis, said frame arms defining a plane; a plug removably mounted on said body between said frame arms and overlying said bore; a nose mounted on ends of said frame arms at a distance from said plug less than 1.0 inches, said nose being positioned coaxially with said flow axis; a deflector plate mounted on said nose and oriented transversely to said flow axis, said deflector plate having a periphery surrounding a center located on said flow axis, said deflector plate comprising: a plurality of first slots extending from said periphery radially toward said center and terminating at a first distance from said flow axis, at least two of said first slots being disposed in said plane; a plurality of second slots extending from said periphery radially toward said center and terminating at a second distance from said flow axis, said second slots being located about said periphery such that one of said second slots is positioned adjacent to each side of each of said first slots which are disposed in said plane; wherein said second distance is less than said first distance.

48. The fire suppression sprinkler of claim 47, where said nose has a maximum radius measured from said flow axis, said first and second distances being greater than said maximum radius.

49. A fire suppression sprinkler, said sprinkler comprising: a body surrounding a bore, said bore defining a flow axis arranged coaxially with said bore; first and second frame arms mounted on opposite sides of said body and extending therefrom in a direction along said flow axis; a nose mounted on ends of said frame arms, said nose being positioned coaxially with said flow axis; a deflector plate mounted on said nose and oriented transversely to said flow axis, said deflector plate having a periphery surrounding a center located on said flow axis and comprising: a first slot extending from said periphery radially toward said center, said first slot having an arrow shape comprising a first shaft extending from said periphery and a first arrowhead terminating at a first distance from said center, said first slot being aligned with said first arm, a widest width of said first slot being equal to or greater than a thickness of said first arm.

50. The sprinkler according to claim 49, wherein said shaft is defined by first and second oppositely disposed edges, each said edge being angularly oriented with respect to a first line extending radially from said center such that said first shaft has a width at said periphery which is greater than a width of said first shaft proximate to said first arrowhead.

51. The sprinkler according to claim 49, wherein a widest width of said first arrowhead is wider than a widest width of said first shaft.

52. The sprinkler according to claim 49, wherein a width of said first arrowhead proximate to said first shaft is greater than a width of said first arrowhead proximate to said center.

53. The sprinkler according to claim 49, wherein said first arrowhead has a curved tip at said first distance from said center.

54. The sprinkler according to claim 49, wherein said first slot is symmetric about a first line extending radially from said center.

55. The sprinkler according to claim 49, further comprising a second slot extending from said periphery radially toward said center, said second slot having a club shape comprising a handle extending from said periphery and a club head terminating at a second distance from said center, wherein a width of said club head proximate to said handle is less than a width of said club head proximate to said center.

56. The sprinkler according to claim 55, wherein a widest width of said club head is wider than a widest width of said handle.

57. The sprinkler according to claim 55, wherein said club head has a curved tip at said second distance from said center.

58. The sprinkler according to claim 55, wherein said club head is asymmetric with respect to a second line extending radially from said center.

59. The sprinkler according to claim 58, wherein said club head is defined by a first edge oriented at a first angle with respect to said second line, and a second edge, opposite to said first edge, said second edge oriented at a second angle with respect to said second line, said second angle being different from said first angle.

60. The sprinkler according to claim 49, further comprising a third slot extending from said periphery radially toward said center, said third slot having a second arrow shape comprising a second shaft extending from said periphery and a second arrowhead terminating at a third distance from said center, wherein said third arrowhead is asymmetric with respect to a third line extending radially from said center.

61. The sprinkler according to claim 60, wherein said second arrowhead is defined by a first edge oriented at a first angle with respect to said third line, and a second edge, opposite to said first edge, said second edge oriented at a second angle with respect to said third line, said second angle being different from said first angle.

62. The sprinkler according to claim 60, wherein a widest width of said second arrowhead is wider than a widest width of said second shaft.

63. The sprinkler according to claim 60, wherein a width of said second arrowhead proximate to said second shaft is greater than a width of said second arrowhead proximate to said center.

64. The sprinkler according to claim 60, wherein said second arrowhead has a curved tip at said third distance from said center.

65. The sprinkler according to claim 60, wherein said second shaft has a width at said periphery which is greater than a width of said second shaft proximate to said second arrowhead.

66. The sprinkler according to claim 60, wherein said second shaft is defined by first and second oppositely disposed edges, each said edge being angularly oriented with respect to said third line such that said second shaft has a width at said periphery which is greater than a width of said second shaft proximate to said second arrowhead.

67. The sprinkler according to claim 49, further comprising a fourth slot extending from said periphery radially toward said center, said fourth slot having a keyhole shape comprising a waist extending from said periphery and a key head terminating at a fourth distance from said center.

68. The sprinkler according to claim 67, wherein a widest width of said key head is wider than a widest width of said waist.

69. The sprinkler according to claim 67, wherein a width of said key head proximate to said waist is equal to a width of said key head proximate to said center.

70. The sprinkler according to claim 67, wherein said key head has a curved tip at said fourth distance from said center.

71. The sprinkler according to claim 67, wherein said key head is symmetric with respect to a fourth line extending radially from said center.

72. The sprinkler according to claim 50, further comprising a fifth slot extending from said periphery radially toward said center, said fifth slot having a third arrow shape comprising a third shaft extending from said periphery and a third arrowhead terminating at a fifth distance from said center, wherein said third shaft is defined by third and fourth oppositely disposed edges, each of said third and fourth edges being angularly oriented with respect to a fifth line extending radially from said center such that said third shaft has a width at said periphery which is greater than a width of said third shaft proximate to said arrowhead.

73. The sprinkler according to claim 72, wherein said third shaft has a width at said periphery wider than a width of said first shaft at said periphery.

74. The sprinkler according to claim 72, wherein a widest width of said third arrowhead is wider than a widest width of said third shaft.

75. The sprinkler according to claim 72, wherein a width of said third arrowhead proximate to said third shaft is greater than a width of said third arrowhead proximate to said center.

76. The sprinkler according to claim 72, wherein said third arrowhead has a curved tip at said fifth distance from said center.

77. The sprinkler according to claim 72, wherein said third arrowhead is symmetric with respect to a fifth line extending radially from said center.

78. A fire suppression sprinkler, said sprinkler comprising: a body surrounding a bore, said bore defining a flow axis arranged coaxially with said bore; first and second frame arms mounted on opposite sides of said body and extending therefrom in a direction along said flow axis; a nose mounted on ends of said frame arms, said nose being positioned coaxially with said flow axis; a deflector plate mounted on said nose and oriented transversely to said flow axis, said deflector plate having a periphery surrounding a center located on said flow axis and comprising: a first slot extending from said periphery radially toward said center, said first slot having an arrow shape comprising a first shaft extending from said periphery and a first arrowhead terminating at a first distance from said center, said first shaft being defined by first and second oppositely disposed edges, each of said first and second edges being angularly oriented with respect to a first line extending radially from said center such that said first shaft has a width at said periphery which is greater than a width of said first shaft proximate to said first arrowhead; a second slot extending from said periphery radially toward said center, said second slot having an arrow shape comprising a second shaft extending from said periphery and a second arrowhead terminating at a second distance from said center, said second shaft being defined by first and second oppositely disposed edges, each said edge defining said second shaft being angularly oriented with respect to a second line extending radially from said center such that said second shaft has a width at said periphery which is greater than a width of said second shaft proximate to said second arrowhead, said second line being oriented at an angle with respect to said first line; a third slot extending from said periphery radially toward said center, said third slot having a club shape comprising a handle extending from said periphery and a club head terminating at a third distance from said center, wherein a width of said club head proximate to said handle is less than a width of said club head proximate to said center, said third slot being positioned between said first and second slots; a fourth slot extending from said periphery radially toward said center, said fourth slot having an arrow shape comprising a third shaft extending from said periphery and a third arrowhead terminating at a fourth distance from said center, said fourth slot being positioned between said second and third slots; a fifth slot extending from said periphery radially toward said center, said fifth slot having a keyhole shape comprising a waist extending from said periphery and a key head terminating at a fifth distance from said center, said fifth slot being positioned between said second and fourth slots.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 is a side view of an example fire suppression sprinkler according to the invention;

[0030] FIG. 1A is a side view of an example fire suppression sprinkler according to the invention;

[0031] FIG. 1B is an isometric view of an example fire suppression sprinkler shown in a pendent orientation;

[0032] FIG. 2 is a partial longitudinal sectional view of the fire suppression sprinkler shown in FIG. 1;

[0033] FIG. 3 is an end view of the fire suppression sprinkler shown in FIG. 1 and showing a plan view of an example deflector according to the invention;

[0034] FIG. 3A is an end view of another embodiment of the fire suppression sprinkler according to the invention showing a plan view of an example deflector;

[0035] FIG. 4 is a plan view of a quadrant of the example deflector shown in FIG. 3; and

[0036] FIGS. 4a, 4B and 4C are plan views of sectors of the deflector, on an enlarged scale, as respectively denoted by arc lengths 4A, 4B and 4C in FIG. 3.

DETAILED DESCRIPTION

[0037] FIGS. 1 and 2 show an example fire suppression sprinkler 10 according to the invention. Sprinkler 10 may be, for example, an early suppression fast response (ESFR) sprinkler having a k factor from about 17 to about 34, and specifically 25.2.

[0038] As shown in FIG. 2, sprinkler 10 comprises a body 12 which surrounds a bore 14. Bore 14 defines a flow axis 16 arranged coaxially with the bore. Body 10 has a nipple 18 for connection of the sprinkler 10 to a piping network of a fire suppression system (not shown) and a plurality of flat surfaces 20 (see FIG. 1) which receive a wrench for applying torque to the sprinkler during installation. Nipple 18 may be threaded as shown in FIGS. 1 and 2, or, as shown in FIG. 1A, nipple 18 may have a groove 22 to enable the use of a mechanical coupling to connect the sprinkler to the piping network of a fire suppression system. First and second frame arms 24 and 26 extend from opposite sides of body 12 parallel to flow axis 16 and support a nose 28 mounted on the ends of the arms. Arms 24 and 26 extend along flow axis 16 by a length 30 as measured from the end of the bore 14 to the base of the nose 28 (see FIG. 2). Nose 28 is positioned coaxially with the flow axis 16 and supports a heat sensitive trigger 32. Nose 28 in this example is conical and has a maximum radius 33 (measured from flow axis 16) which transitions into a flow conditioning portion 34. Flow conditioning portion 16 is advantageously cylindrical, and extends beyond the ends of arms 24 and 26 a length 36 (see FIG. 1), thereby permitting a deflector to be mounted on nose 28 in spaced relation to the ends of arms 24 and 26.

[0039] In this example the heat sensitive trigger 32 comprises a frangible glass bulb 38 containing a heat sensitive liquid 40. Bulb 38 extends between nose 28 and a sealing member 42, in this example a plug 44 which overlies and seals the bore 14 through engagement with body 12. As shown in FIG. 2, nose 28 also comprises a set screw 46, threaded within a bore 48 in nose 28 aligned with the bulb 38. The set screw 46 permits assembly of the bulb 38 into the sprinkler 10 and adjustment of the compression force on the bulb. Bulb 38 supports the plug 44 to maintain the sprinkler 10 in its closed configuration (shown). Bulb 38 breaks when the ambient temperature reaches a predetermined value, for example, indicative of a fire. In various embodiments, such predetermined temperature values may be approximately 155? F. or 200? F. When the bulb 38 breaks it no longer supports plug 44 which is then released from engagement with the body 12 to open sprinkler 10 and allow water or other fire suppressing fluid to be discharged. Other heat sensitive triggers are also feasible, such as those having components held together by a solder which melts at a predetermined temperature to allow the sprinkler to open.

[0040] A deflector 50 is mounted on the nose 28. As shown in FIGS. 2 and 3, the example deflector 50 comprises plate 52, advantageously circular and in a plane oriented transversely to the flow axis 16. Plate 52 has a periphery 54 surrounding a center 56, the center being coincident with the flow axis 16. Plate 52 has a thickness 58 (see FIG. 1). The deflector 50 is positioned in spaced relation to the ends of arms 24 and 26 at the distance 36. In an example embodiment, the distance 36 is greater than twice the thickness 58 of plate 52. In another example embodiment, the distance 36 is approximately three times the thickness 58 of the plate 52.

[0041] As shown in FIGS. 3 and 4, plate 52 defines a plurality of slots 62. Slots 62 are designed in conjunction with nose 28, arms 24 and 26 (including the length 30), flow conditioning region 34 (including length 36), and bore 14 to meet standards governing discharge rate, coverage area size and shape, and other performance standards in order to permit installation under NFPA 13, including passage of the testing set forth in standards promulgated by FM Global and UL, such standards including UL 1767 and FM 2008.

[0042] The example sprinkler 10 is further designed to achieve higher performance, including enabling the higher density storage of commodities by being qualified under UL 1767 (and permitted under NFPA 13) to be installed in specific applications where the ceiling height is a maximum of 48 feet, the commodity height is a maximum of 43 feet and where the aisle spacing is a minimum of 4 feet.

[0043] To this end, slots 62 comprise slots of five configurations, slots 64, slots 66, slots 68, slots 70, and slots 72, respectively, all of which extend radially from the periphery 54 of the plate 52 toward the plate center 56, each slot extending along a respective line 74, 76, 78, 80 and 82 which extend radially from the plate center 56.

[0044] As is apparent from FIG. 3, slots 64 are aligned with the first and second arms 24 and 26 which are disposed in a plane 84. As shown in FIGS. 4 and 4C, slots 64 extend from the periphery 54 of the plate 52 and terminate at points 64a which lie at a distance 86 from the plate center 56. Slots 64 are of generally arrow shape, arrow shape meaning that slots 64 have a shaft 64b extending from the periphery 56 and an arrowhead 64c terminating in a curved tip 64d at point 64a. Slots 64 in this example are symmetric about line 74 and the arrowhead 64c has a width 64e proximate to the shaft 64b which is greater than its width 64f proximate the plate center 56. As shown in FIG. 3, width 64e may be advantageously equal to or greater than the thicknesses 24a and 26a of the arms 24 and 26 respectively. With reference again to FIGS. 4 and 4C, width 64e, the widest width of the arrowhead 64c is also wider than the widest width of the shaft 64b in this example.

[0045] Advantageously, the shaft 64b is defined by first and second oppositely disposed edges 64g and 64h which are angularly oriented with respect to line 74 such that shaft 64b has a width 64i at the plate periphery 54 which is greater that a width 64j of the shaft 64b proximate to the arrowhead 64c.

[0046] As shown in FIGS. 3, 4 and 4B, slots 66 are adjacent each side of the two slots 64, and extend from the periphery 54 of plate 52 to terminate at points 66a which lie at a distance 88 from the plate center 56. Slots 66 are generally club shaped, club shape meaning that slots 66 comprise a handle 66b extending from the periphery 54 and a club head 66c terminating at point 66a. The width 66d of the club head 66c proximate to handle 66b is less than the width 66e of the club head proximate to the plate center 56. Club head 66c terminates at point 66a in a curved tip 66f. The widest width 66e of the club head is wider than the widest width 66g of the handle 66b.

[0047] As shown in FIG. 4B, slots 66 are preferably asymmetric about lines 76. Club head 66c is defined by a first edge 66h oriented at a first angle 66i with respect to line 76, and a second edge 66j oriented at a second angle 66k with respect to line 76. Angle 66i is different from angle 66k to produce the asymmetry of slots 66. Slots 66 advantageously have the largest surface area of any of slots 64, 68, 70 and 72.

[0048] As shown in FIGS. 3, 4 and 4B, slots 68 extend from the periphery 54 of the plate 52 and terminate at points 68a which lie at a distance 90 from the plate center 56. Slots 68 are of generally arrow shape, arrow shape meaning that slots 68 have a shaft 68b extending from the periphery 56 and an arrowhead 68c terminating in a curved tip 68d at point 68a. The arrowhead 68c has a width 68e proximate to the shaft 68b which is greater than its width 68f proximate the plate center 56. Width 68e, the widest width of the arrowhead 68c is also wider than the widest width of the shaft 68b in this example.

[0049] Advantageously, the shaft 68b is defined by first and second oppositely disposed edges 68g and 68h which are angularly oriented with respect to line 78 such that shaft 68b has a width 68i at the plate periphery 54 which is greater that a width 68j of the shaft 68b proximate to the arrowhead 68c.

[0050] As shown in 4B, slots 68 in this example are asymmetric about line 78. Arrowhead 68c is defined by a first edge 68k oriented at a first angle 68m with respect to line 78, and a second edge 68n oriented at a second angle 68p with respect to line 78. Angle 68m is different from angle 68p to produce the asymmetry of slots 68.

[0051] As shown in FIGS. 3, 4 and 4A, slots 70 lie between slots 68 and 72 and extend along line 80 from the plate periphery 54 to terminate at a point 70a at a distance 92 from the plate center 56. Slots 70 are generally elongate keyhole shaped, elongate keyhole shaped meaning that slots 70 comprise a waist 70b extending from periphery 54 and a key head 70c terminating at point 70a in a curved tip 70d. Slots 70 are symmetric about lines 80 in this example. The width 70e of the key head 70c proximate the waist 70b is equal to the width 70f of the key head proximate the plate center 56. The widest width 70e or 70f is wider than the widest width 70g of the waist 70b.

[0052] FIG. 3A shows another embodiment wherein slots 70, having the keyhole shape, are positioned adjacent each side of the two slots 64, and extend from the periphery 54 of plate 52, effectively replacing slots 66.

[0053] As shown in FIGS. 3, 4 and 4A, slots 72 extend from the periphery 54 of the plate 52 and terminate at points 72a which lie at a distance 94 from the plate center 56. Slots 72 are of generally arrow shape, arrow shape meaning that slots 72 have a shaft 72b extending from the periphery 56 and an arrowhead 72c terminating in a curved tip 72d at point 72a. Slots 72 in this example are symmetric about lines 82 and the arrowhead 72c has a width 72e proximate to the shaft 72b which is greater than its width 72f proximate the plate center 56. Width 72e, the widest width of the arrowhead 72c is also wider than the widest width of the shaft 72b in this example.

[0054] Advantageously, the shaft 72b is defined by first and second oppositely disposed edges 72g and 72h which are angularly oriented with respect to line 82 such that shaft 72b has a width 72i at the plate periphery 54 which is greater that a width 72j of the shaft 72b proximate to the arrowhead 72c. It is also advantageous when width 72i is greater than the width 64i of the shaft 64b at the periphery. It is also advantageous for line 82 to be oriented at 90? to line 74, resulting in slot 72 being oriented at 90? to slot 64. Additionally, with respect to the distances 86, 88, 90, 92 and 94, it is advantageous if distance 88 is less than distances 86, 90, 92 and 94. It is further advantageous if the distance 92 is less than distances 86, 90 and 94. Moreover, it is advantageous if distances 86, 90 and 94 are equal to one another.

[0055] The example arrangement of the slots 62 shown in FIG. 3 is expected to be advantageous. In this arrangement there are five different types of slots 62. Slots 64 may be regarded as a pair of first slots (first configuration) positioned in plate 52 at 180? from one another. Slots 72 may be considered a pair of second slots (second configuration) positioned in plate 52 at 90? and 270? from either one of the first slots 64. Slots 66 may be considered as third slots (third configuration). In the example arrangement, there are four of the third configuration slots 66 positioned in plate 52 at 22.5?, 157.5?, 202.5? and 337.5? from one of the first slots 64. Slots 68 may be considered to be fourth slots (fourth configuration). In the example arrangement there are four fourth configuration slots positioned in plate 52 respectively at 45?, 135?, 225? and 315? from one of the first slots 64. Slots 70 may be considered to be fifth slots (configuration type). In the example arrangement there are four fifth configuration slots positioned in plate 52 respectively at 67.5?, 112.5?, 247.5? and 292.5? from one of the first slots 64. It is understood that the angular separation of the slots are exemplary nominal angles subject to manufacturing tolerances and thus may vary from those as specified herein.

[0056] The arrangement of slots 62 as shown in FIG. 3 may also be characterized based upon the distance at which the slots terminate from the flow axis 16. In the example embodiment shown, a plurality of first slots, including, for example, slots 64, 68 and 72, and a plurality of second slots, including, for example, slots 66 and 70, extend radially from the periphery 54 toward the flow axis 16. In particular, two of the first slots 64 are disposed in the plane 84 (aligned with the arms 24 and 26) and one of the second slots 66 are positioned adjacent to each side of each of the first slots 64 which are disposed in plane 84. With reference to FIG. 4, it is thought advantageous for the termination distance 88 of second slots 66 from the flow axis 16 be less than the termination distance 86 from the flow axis of the first slots 64. Further advantage is believed possible if the termination distances 88 and 86 from the flow axis 16 are greater than the maximum radius 33 (see FIG. 1) of the nose 28. For a pendent ESFR sprinkler 10 (see FIGS. 1 and 1B) with the arrangement of first and second slots described above, it is desirable that the nose 28 be mounted on ends of the frame arms 24 and 26 at a distance 96 of less than 1.0 inches from the plug 44 as shown in FIG. 1. As shown in FIG. 1A, pendent sprinklers are mounted in a pipeline 98 with the flow axis 16 oriented vertically so that the discharge of fire suppressing fluid is in a downward direction.

[0057] The arrangement of slots 62, meaning their angular separation, shape, sizing as well as their orientation and spacing with respect to arms 24 and 26 according to the invention is believed to promote improved performance of fire sprinklers, especially of ESFR sprinklers, by advantageously compensating for the effect known as frame shadowing, whereby arms 24 and 26 represent a discontinuity in the flow of fluid exiting bore 14 to impinge upon deflector 50. In particular, it is believed that the location of slots with the largest surface area or which extend the deepest toward the axis 16 (such as slots 66) adjacent to the slots located above the frame arms (such as slots 64) helps to compensate for frame shadowing. It is further believed that the location of symmetric slots remote from the location of the frame arms (such as slots 70 and 72) where the effect of frame shadowing is at a minimum promotes uniform distribution of fluid where the flow is at its most uniform due to the limited effects of frame shadowing. This arrangement may also be viewed as one where any of slot length, area, and asymmetry is generally reduced from a localized maximum above or adjacent to the frame arms to a localized minimum equidistant from the frame arms, and that such reduction takes place independently on the first and second slots having different termination distances from the flow axis. The advantageous arrangements of the invention, which offer improved compensation for the effects of frame shadowing, result in a more uniform distribution of water discharged from sprinkler 10 is promoted that is believed to result in improved performance.

[0058] Fire suppression sprinklers according to the invention are expected to meet or exceed the standards for ESFR sprinklers including by meeting the requirements of UL1767 and resulting in approvals at reduced aisle widths, and better, more uniform performance under all listed conditions.