Balanced flue heating appliances

Abstract

 An opening (14) is formed in a wall of the combustion chamber of a balanced flue heating appliance and a closure member (13) is provided for selectively closing the opening. A lever (19) is provided for moving the closure member (13) out of its closed position and a detent formation (26) is engaged by the lever (19) for maintaining the closure member (13) in an open position in which, during use of the heating appliance, the efficiency of the heating appliance is reduced substantially as compared to the efficiency obtained when the closure member (13) is in its closed position.

Description

Field of the Invention

[0001] This invention relates to balanced flue heating appliances which, typically, include a combustion chamber within which there is a burner to which a fuel is supplied, and a balanced flue system for the supply of air to the combustion chamber and for the discharge of combustion products from the chamber.

[0002] It is an object of the present invention to provide an improved form of balanced flue heating appliance.

Summary of the Invention

[0003] According to the present invention there is provided a balanced flue heating appliance in which an opening is formed in a wall of the combustion chamber and in which a closure member is provided for selectively closing the opening, means being provided for moving the closure member out of its closed position and for maintaining the closure member in an open position in which, during use of the heating appliance, the efficiency of the heating appliance is reduced substantially as compared to the efficiency obtained when the closure member is in its closed position.

[0004] The closure member is preferably pivotally mounted and spring means is preferably provided for urging the closure member into its closed position such that, when in its closed position, the closure member serves as an excess pressure relief member in the event of an explosion within the combustion chamber.

[0005] The closure member is preferably located at or adjacent the base of the combustion chamber adjacent the burner.

[0006] The means for moving the closure member out of its closed position is preferably in the form of a lever located adjacent the base of the heating appliance and projecting forwardly into a position in which the forward end thereof is readily accessible to enable a user of the appliance to effect movement of the closure member out of its closed position.

[0007] The spring means for urging the closure member into its closed position is preferably in the form of a spring that surrounds the lever and acts between a pair of spaced washers mounted on the lever, the washers being slidable relative to the lever and stop means being provided for limiting the maximum spacing of the washers.

[0008] The means for maintaining the closure member in its open position preferably includes a detent formation. The arrangement is preferably such that, when the closure member is in its closed position, one of the pair of spaced washers engages the detent formation whereas, when the closure member is in its open position, the other one of the pair of spaced washers engages the detent formation.

[0009] When the closure member is in its closed position, the balanced flue heating appliance will operate with its design efficiency whereas, when the closure member is in its open position and additional air for combustion enters the combustion chamber, the efficiency of the appliance is reduced and, at the same time, the size of the flame that is obtained is reduced.

[0010] Thus, during cold weather, the appliance can be used at its maximum efficiency whereas, during the summer, the closure member can be moved to its open position so that the thermal output of the appliance is substantially reduced while, at the same time, the size of the flame is increased to enhance the aesthetic appeal of the appliance.

Brief Description of the Drawings

[0011] 

Figure 1 is a perspective view of a balanced flue heating appliance from in front and underneath showing the closure member in its closed position,

Figure 2 is a perspective view of the balanced flue heating appliance of Figure 1 from in front and underneath showing the closure member in its open position,

Figure 3 is an enlarged detail view showing the burner assembly and the closure member in its closed position,

Figure 4 is a view corresponding to Figure 3, but showing the closure member in its open position, and

Figure 5 is an enlarged view of a lever for moving the closure member from its closed to its open position.

Description of the Preferred Embodiment

[0012] The balanced flue heating appliance shown in the drawings is a balanced flue gas stove having a housing 10 within which there is a combustion chamber to which combustion air is supplied and from which combustion products are discharged via a balanced flue system (not shown) connected to an opening 11 A in the top wall of the housing 10. The front of the combustion chamber is closed by a transparent ceramic glass plate (not shown) and a service opening 11 B is formed in the bottom wall of the housing 10 adjacent the burner assembly 12. The provision of the service opening 11B enables a service or installation engineer to obtain access to the interior of the combustion chamber but this opening 11 B is closed by a plate (not shown) fixed in position by threaded fasteners.

[0013] Fuel for combustion is supplied via the burner assembly 12, which has operating elements that are located adjacent the base of the housing 10 and are accessible from the front of the housing 10. The balanced flue appliance of the present invention is thus arranged to operate in the same manner as a standard balanced flue gas stove and to provide the same operating efficiency and thermal output as such a stove.

[0014] The heating appliance of the present invention differs from a standard balanced flue gas stove in that it includes a pivotally mounted closure member or flap 13 that normally closes an opening 14 formed in the bottom wall of the housing 10. The closure member or flap 13 includes a closure plate that is of generally rectangular form, as is the opening 14. A generally U-shaped bracket 15 is attached to the rectangular closure plate and the arms of the U-shaped bracket 15 are connected by a pivot rod 16 to a pair of mounting elements 17 located adjacent the burner assembly 12. The closure member 13 is arranged for pivotal movement about the axis of the pivot road 16 between a closed position, as shown in Figures 1 and 3, and an open position, as shown in Figures 2 and 4.

[0015] A lever assembly 18 is connected to one of the arms of the generally U-shaped bracket 15 and the lever assembly is shown in detail in Figure 5. The lever assembly 18 includes an elongated lever 19 that is provided at its one end with an annular formation 20 to receive the shank of a bolt by which the lever assembly 18 is connected to the arm of the U-shaped bracket 15. A knob 21 is provided at the other end of the elongated lever 19 and is so located that access thereto can readily be obtained to enable the user of the appliance to grasp the knob 21 and pull the lever assembly 18 to effect movement of the closure member 13 from its closed position. As can be seen from the drawings, the lever 19 projects forwardly from a position beneath the burner assembly 12 and to one side of the centre of the front of the housing 10 such that the user can safely effect movement of the closure member 13.

[0016] Two washers 22 and 23 are mounted on the elongated lever 19 and have dimensions such that they are slidable longitudinally of the lever 19. A helical compression spring 24 is mounted on the elongated lever 19 between the two washers 22 and 23 and split pins 25 (of which only one can be seen in the drawings) pass through openings in the elongated lever 19 and act as stops to limit the extent of travel of the washers 22 and 23 towards the ends of the elongated lever 19.

[0017] The lever assembly 18 is arranged to cooperate with a detent formation 26 that is mounted on the bottom wall of the housing 10 adjacent the burner assembly 12. The detent formation 26 includes a plate formed with an L-shaped cut-out 27 so that the elongated lever 19 can be moved into the stem of the cut-out 27 and then, when it reaches the top of the cut-out 27, can be moved horizontally into the foot of the cut-out 27 so as to be retained in position. The plate in which the cut-out 27 is formed has a pair of inclined guide portions 28.

[0018] When the closure member 13 is located in its open position, as shown in Figures 2 and 4, washer 23 is disposed in engagement with the plate in which the cut-out 27 is formed and the washer 23 is urged into engagement with the plate by means of the spring 24. The spring-loaded frictional engagement of the washer 23 with the plate will thus serve to prevent inadvertent movement of the lever assembly 18 out of engagement with the detent formation 26.

[0019] When it is desired to move the closure member 13 from its open position, as shown in Figures 2 and 4, into its closed position, as shown in Figures 1 and 3, the user of the appliance will grasp the knob 21 and will move the lever assembly 18 downwardly out of the cut-out 27 against the increased spring resistance resulting from movement of the washer 23 past the inclined guides 28. Once the user has moved the lever assembly 18 downwardly to a sufficient extent clear of the detent formation 26, the action of the spring 24 will serve to move the closure member 13 into its closed position, as shown in Figures 1 and 3.

[0020] Once the closure member 13 can be moved by the action of the spring 24 into its closed position, the user will move the lever assembly 18 upwardly once more for re-engagement with the detent formation 26. During such upward movement the other washer 22 will engage the inclined guides 28 so that, by the time that the lever assembly 18 has been moved upwardly to its fullest extent and the elongated lever is in the horizontal leg of the L-shaped cut-out 27, the spring 24 has been subjected to a predetermined degree of compression and the closure member 13 is acted upon by the spring 22 so as to be held resiliently in its closed position.

[0021] To move the closure member 13 to its open position from its closed position, the user will grasp the knob 21 and will cause the lever assembly 18 to move downwardly and outwardly out of engagement with the detent formation 26 and then, once the closure member is fully open, the lever assembly 18 will be moved back upwardly into engagement with the detent formation 26.

[0022] During the winter (or during periods of cold weather), the closure member 13 will be in its closed position and the balanced flue gas stove will operate in its normal manner, i.e. with its design efficiency and thermal output. The closure member 13 is spring-loaded into its closed position such that, if there are any sudden, drastic increases in pressure within the combustion chamber, the closure member 13 will open, i.e. the closure member 13 acts as an excess pressure relief member avoiding damage to the heating appliance resulting from any "explosions" that may occur within the combustion chamber.

[0023] When, during warmer weather, the high thermal output of the balanced flue gas stove is not required and the user of the stove is more interested in obtaining a "homely" aesthetic appearance, e.g. he or she wishes to obtain a substantially larger and more visible flame than that which is normally obtained, the closure member 13 will be moved into its open position. When the closure member 13 is in its open position, the air for combustion will enter the combustion chamber through the opening 14, which is in the base of the combustion chamber adjacent the burner assembly 12, and a large flame effect will be obtained. The combustion products may exit from the combustion chamber through both parts of the balanced flue system or the cool excess air may pass through the outer passage of the balanced flue system.

[0024] With the closure member 13 in its open position, the operating efficiency of the gas stove is very significantly reduced while, at the same time, the visual appeal of the gas stove is increased.

Claims

1. A balanced flue heating appliance in which an opening (14) is formed in a wall of the combustion chamber and in which a closure member (13) is provided for selectively closing the opening (14), means (18, 26) being provided for moving the closure member (13) out of its closed position and for maintaining the closure member (13) in an open position in which, during use of the heating appliance, the efficiency of the heating appliance is reduced substantially as compared to the efficiency obtained when the closure member (13) is in its closed position.

2. A heating appliance as claimed in Claim 1, in which the closure member (13) is pivotally mounted.

3. A heating appliance as claimed in Claim 1 or Claim 2, in which spring means (24) is provided for urging the closure member (13) into its closed position such that, when in its closed position, the closure member (13) serves as an excess pressure relief member in the event of an explosion within the combustion chamber.

4. A heating appliance as claimed in any one of the preceding claims, in which the closure member (13) is located at or adjacent the base of the combustion chamber adjacent the burner (12).

5. A heating appliance as claimed in any one of the preceding claims, in which the means for moving the closure member (13) out of its closed position includes a lever (19) located adjacent the base of the heating appliance and projecting forwardly into a position in which the forward end thereof is readily accessible to enable a user of the appliance to effect movement of the closure member (13) out of its closed position.

6. A heating appliance as claimed in Claim 5, as dependant on Claim 3, in which the spring means for urging the closure member (13) into its closed position is in the form of a spring (24) that surrounds the lever (19) and acts between a pair of spaced washers (22 and 23) mounted on the lever (19).

7. A heating appliance as claimed in Claim 6, in which the washers (22 and 23) are slidable relative to the lever (19) and stop means (25) are provided for limiting the maximum spacing of the washers (22 and 23).

8. A heating appliance as claimed in Claim 6 or Claim 7, in which the means for maintaining the closure member (13) in its open position includes a detent formation (26).

9. A heating appliance as claimed in Claim 8, in which the arrangement is such that, when the closure member (13) is in its closed position, one (22) of the pair of spaced washers engages the detent formation (26) whereas, when the closure member (13) is in its open position, the other one (23) of the pair of spaced washers engages the detent formation (26).

10. A heating appliance as claimed in Claim 8 or Claim 9, in which the detent formation (26) includes a plate formed with an L-shaped cut-out (27).

Drawing