Residential concealed sprinkler

An automatic fire protection sprinkler includes a sprinkler body having a passage with an inlet end and a discharge opening. A pair of sprinkler arms extend from the sprinkler body. The pair of sprinkler arms each include a radially inwardly extending leg including a threaded bore for receiving a compression screw. The pair of sprinkler arms each include a radially outwardly extending leg each defining an aperture therein. An outlet closure assembly includes a closure element that selectively blocks the discharge opening of the sprinkler body and a trigger assembly including a yoke that engages the compression screws and a glass bulb that extends between the yoke and the closure element. A deflector is coupled to the sprinkler arms by a pair of support pins that are received in the apertures in the radially outwardly extending legs of the at least two sprinkler arms.

FIELD

The present disclosure relates to fire protection sprinklers and more particularly to a residential concealed sprinkler.

BACKGROUND

Sprinklers have long been used in automatic fire extinguishing systems in order to controllably disburse a fluid to suppress or extinguish a fire in a designated area. Typically, the fluid utilized in automatic fire extinguishing systems is water, however systems have also been developed to disburse other fire extinguishing fluids. In one common design, sprinklers include a solid metal base with an inlet connected to a pressurized supply of water or other fire extinguishing fluid, and a deflector which alters the trajectory of the water in an optimum pattern when discharged from the base outlet orifice. In many conventional sprinklers the deflector is fixedly spaced from the outlet by a pair of rigid arms and mounted on a boss joining the arms. A trigger element is positioned between the deflector boss and the outlet orifice closure seal.

In another common recessed, pendant version of the sprinkler, the deflector is movable and stored proximate to the base. A housing extends around the deflector and sprinkler body and forms a recess up into the ceiling in which the sprinkler is located. A fluid seal, also positioned within the interior of the sprinkler, is maintained in the closed position by a pair of levers or actuators depending below the bottom of the sprinkler body. The levers are held in an inwardly biased or closed position by a trigger mechanism which is thermally responsive in the temperature range indicative of a fire. The trigger mechanism is commonly a thermally sensitive fusible link. Thus, under normal temperatures, the presence of the thermally sensitive fusible link prohibits fluid flow from the sprinkler. When the temperature within the designated area rises to a preselected value due to a fire, the fusible link separates, causing the levers to move in an outward direction and thus permits downward movement of the deflector plate from the interior of the sprinkler to a preselected distance within the interior of the designated area. The separation of the fusible link also opens the fluid seal, thereby enabling pressurized water to travel through the sprinkler and into the designated area in order to suppress or extinguish a fire.

The prior art has advanced fusible link trigger mechanisms which also function to conceal the bottom outlet of the sprinkler. For example, U.S. Pat. No. 4,596,289 issued to Johnson discloses a combined trigger element and concealing mechanism having two complementary strut retaining members which maintain the fluid seal in a closed position. The outer surfaces of these strut retaining members are joined by a heat fusible material which is covered by a heat conductive cover. In this design, the bottom outlet of the sprinkler is entirely enclosed by the combined trigger and concealing mechanism.

The cover mechanism entirely encloses the bottom of the sprinkler, with the heat fusible material being located on the interior surface of the cover. When the temperature is elevated due to the presence of a fire in the designated area, the thermal energy issued from the fire is constrained to pass in an upward direction from the outer surface of the cover member towards the heat sensitive compound. Since the cover member completely encloses the bottom region of the sprinkler, the inner surface of the cover member and the heat sensitive agent remains at ambient or near ambient conditions until thermal energy penetrates the cover member and reaches the heat sensitive agent.

Consequently, there exists a need for a responsive and reliable combined trigger and concealing device which overcomes the difficulties encountered by the prior art.

SUMMARY

The present disclosure provides an automatic fire protection sprinkler including a sprinkler body having a passage with an inlet end and a discharge opening. A pair of sprinkler arms extend from the sprinkler body on opposite sides of the discharge opening. The pair of sprinkler arms each include a radially inwardly extending leg extending toward one another and spaced from one another. The radially inwardly extending legs each include a threaded bore for receiving a compression screw. The pair of sprinkler arms each including a radially outwardly extending leg each defining an aperture therein. An outlet closure assembly includes a closure element that selectively blocks the discharge opening of the sprinkler body and a trigger assembly including a yoke that engages the compression screws and a glass bulb that extends between the yoke and the closure element. A deflector is coupled to the sprinkler arms by a pair of support pins that are received in the apertures in the radially outwardly extending legs of the at least two sprinkler arms.

According to a further aspect of the present disclosure, the yoke includes a crossbar having a U-shaped midsection with a first recess in a first side and a pair of ends each including a second recess therein on a second side opposite the first side. An ejection structure extends from the crossbar. The yoke is made from a stamped flat blank that is stamped from sheet metal. The stamped blank can be generally “D”-shaped and includes a straight section and an arc shaped extension extending from opposite ends of the straight section. The arc shaped extension can be bent so as to be generally perpendicular to the straight section. The straight section can be stamped to include a recess at each end facing in a direction away from the bent arc shaped extension. The additional central recess can be formed in a center of the straight section facing in a direction toward the bent arc shaped extension. A midsection of the straight section is bent in a U-shape so as to extend away from the bent arc shaped extension.

DETAILED DESCRIPTION

With reference toFIG. 1, a residential concealed sprinkler10according to the principles of the present disclosure will not be described. The residential concealed sprinkler10includes a sprinkler body12includes a fluid passage14defining an inlet opening16and a discharge opening18. The body12includes an upper section having external threads20. The body12further includes a pair of frame arms22spaced from one another on opposite sides of the discharge opening18.

The pair of frame arms22each include a radially inwardly extending leg portion24and a radially outwardly extending leg portion26. Each of the radially inwardly extending leg portions24includes a threaded bore28that receives a compression screw30. The compression screws30each engage a yoke32that extends between the compression screws30. The yoke32engages a glass bulb34at a distal end and a proximal end of the glass bulb34engages a seal assembly36. The seal assembly36can include an annular spring washer38and pip cap assembly40.

As shown inFIG. 8, the yoke32includes a bent crossbar42having a U-shaped mid-section44with a center recess46for receiving the distal end of the glass bulb34. The ends48of the crossbar42extend from the U-shaped mid-section and each include a recess50on an opposite side of the crossbar42from the recess46. The yoke32can further include an upwardly extending ejection structure52disposed on one side of the crossbar42. The ejection structure52provides a pivot point for causing the yoke32to pivot and eject outwardly from the sprinkler when the glass bulb34shatters due to the heat of a fire. The ejection structure52can be in the form of a continuous structure extending from opposite ends48of the crossbar42.

The yoke is made from a flat blank100that is stamped from sheet metal, as shown inFIG. 11. The stamped blank100can be generally “D”-shaped and includes a straight section102and an arc shaped extension104extending from opposite ends of the straight section102. The arc shaped extension104can be bent so as to be generally perpendicular to the straight section102, as shown by the bent extension portion52inFIGS. 8 and 10. The straight section102can be stamped to include the recess50at each end facing in a direction away from the bent arc shaped extension52. The additional central recess46can be formed in a center of the straight section102facing in a direction toward the bent arc shaped extension52. The midsection of the straight section102is bent in a U-shape44so that the base of the U extends away from the bent arc shaped extension52.

A deflector assembly60is supported to the pair of radially outwardly extending legs26of the sprinkler body12by a pair of support pins62that are received in apertures64. The support pins62are engaged with apertures66provided in a deflector plate68. The deflector plate68can be oval shaped and include a plurality of slots70extending inward from an outer periphery of the plate68to define a plurality of tines72so as to provide a desired spray pattern. The size and shape of the slots70can be selected to provide a desired flow pattern in order to distribute water being discharged from the discharge opening18so as to meet the necessary distribution pattern for suppressing a fire in a desired coverage area. A deflector button74can be secured to a center of the deflector plate68. The deflector button74can be sized and shaped to distribute the flow of water through the discharge opening18radially outward across the surface of the deflector plate68. The deflector button74can have a cone shaped face76and a cylindrical base78that is staked to the deflector plate68.

A can-shaped housing80can be mounted to the sprinkler body12. As is well known in the art, a cover assembly (not shown) can be mounted to the can-shaped housing80for concealing the sprinkler10in an installed condition.