Patent Application
20080276925
Baking ovens are generally known in the art and provide an enclosed volume for placement of a food product to be baked therein and a heat source to bake the food product in the presence of heated air. The enclosed volume of a baking oven normally includes a frame with a plurality of walls that enclose a substantial portion of the enclosed cooking volume. The frame is usually formed from insulated materials that provide a relatively low thermal conductivity, or a high resistance path for heat to leave the enclosed volume of the oven to the atmosphere.
One or more doors are normally provided on an oven to allow the enclosed volume to be selectively opened for placement or removal of a food product within the enclosed volume. Doors are typically closed as much as possible to limit the heat that escapes the oven through the opening in the enclosed volume formed when the doors are opened. Further, because the enclosed volume of the oven is maintained at an elevated temperature to bake the food product, an oven door that is susceptible to be spuriously or inadvertently opened would provide a safety hazard for restaurant employees that work in close proximity to a heated oven.
Because it is desired to reliably maintain the doors closed (i.e. the internal surface of the door contacting the frame and substantially sealing the enclosed volume of the oven), a number of methods of maintaining the oven doors closed are known in the art.
Other designs that hold oven doors closed are known in the art such as complex locks or latches that provide mechanical contact between the door and the frame. These complex mechanisms are useful at retaining a door in a closing position with respect to the oven frame, but are often undesirable because they often include a complex opening and/or shutting procedure that reduces the efficiency of a restaurant employee that must use the oven. Accordingly, it is desired to provide an oven with an openable door that can be reliably maintained in a closed position to enclose the cooking volume, while including a convenient and simple opening and closing mechanism.
A first representative embodiment of the disclosure provides a latch mechanism for an oven door. The latch mechanism includes a bar defined within a frame of the oven, a door rotatably mounted to the frame, and a latch arm pivotably mounted to the door. A handle is pivotably mounted to the door a pin is constrained with the handle and extends through the slot in the latch arm. The latch arm engages the bar in a first position of the handle and the latch arm rotates free of the bar in a second position of the handle, and the contact between the pin and the slot defines a range of travel of the latch arm with respect to the handle.
A second representative embodiment of the disclosure provides an oven. The oven includes a partially enclosed cooking compartment defined by a frame with an inlet opening, the periphery of the cooking compartment includes a bar. A pivotable door is engaged with the housing to fully enclose the cooking compartment. The door includes a pivotable latch arm. A first pin is pivotably connected to the latch arm and a handle and a second pin extends in parallel to the first pin and through a slot in the latch arm. The latch arm and the handle are pivotably connected by the first pin and the latch arm is pivotable by pivoting the handle with respect to the door.
a is the view of
Turning now to the figures, a baking oven 10 is provided. The baking oven 10 includes a frame 20 that encloses a substantial portion of a cooking volume 13 of the oven 10. The frame 20 additionally encloses a heat source 24 that is disposed within the cooking volume 13. The heat source 24 may be provided from burners that combust natural gas or other types of fuel to produce heat, or from electric heaters that produce heat with current flow therethrough due to their high internal resistance. The frame 20 may further enclose and support a fan 25 that provides air circulation within the cooking volume 13 to evenly bake a food product disposed within the cooking volume 13.
The cooking volume 13 is normally fully enclosed by at least one door 30 that is pivotably mounted to the frame 20. In some embodiments, two or more doors 30 may be pivotably mounted to the frame 20 to enclose the cooking volume 13. The two or more doors 30 may each be independently openable, or in some embodiments, the two or more doors 30 may be only operated in a specific sequence due to the physical geometry of the doors 30 and their location with respect to each other on the oven frame 20.
The door 30 is pivotably mounted to the frame 20 and movable between an open position where the user can access the cooking volume 13 of the oven 10 and a closed position (
The door 30 is removeably retained in the closed position with respect to the frame 20 with a latch mechanism 40. The latch mechanism 40 is mounted to the door 30 to selectively provide and remove a connection between a pivotable latch arm 50 and a bar 28 on the frame 20. In some embodiments, the latch mechanism 40 is a single assembly that can be readily mounted or removed from the door 30 using only one or two screws or other fasteners (not shown). The latch arm 50 is mounted to an operator 44 that extends outwardly (i.e. from the outer surface 31 of the door 30) from one of the top or bottom surface 33, 34 of the door 30. The operator 44 is connected to a handle 90 that may be disposed parallel to the door 30. The operator 44 (and the handle 90 connected thereto) is pivotably connected to the door 30 and constrained by two shoulders 86a, 86b provided on a plate 86 that is disposed on the specific top or bottom 33, 34 surface of the door 30. In some embodiments, contact between the first and second shoulders 86a, 86b and the operator 44 defines the range of motion of the operator 44 and the handle 90 with respect to the door 30. For example, the first side 45a of the operator 44 normally contacts the first shoulder 86a to limit the pivoting of the operator 44 due to the biasing force of the spring 76 (discussed below). The operator 44 and the handle may be pivoted until the second side 45b contacts the second shoulder 86, which limits the potential rotation of the latch arm 50 in the direction Y (as shown on
The operator 44 receives a first pin 60 that extends through an aperture in the plate 86 and the latch arm 50 and is pivotably mounted to a bracket 80 that is rigidly mounted to the door 30. In some embodiments, the first pin 60 is rigidly mounted to the operator 44 with a spline, a keyed connection, a weld joint, or another suitable connection between the two members to prevent relative pivoting. The bracket 80 is shaped and disposed within the door to define and partially enclose an internal volume 80a that receives and provides space for pivotal movement of the latch arm 50, a constraining bracket 70, a second pin 64, and a spring 76, each of which are discussed below.
The first pin 60 extends through a first aperture 71 in the constraining bracket 70, which is disposed below the plate 86. Each of the first pin 60 and the constraining bracket 70 include holes 62, 73, respectively, that receive a dowel 74 when the two holes 62, 73 are coaxially aligned. The dowel 74 provides a removable connection between the first pin 60 and the constraining bracket 70 to rigidly connect the two members together. The first pin 60 further extends through an aperture 52 in the latch arm 50 and finally through an aperture (not shown) in the bracket 80.
In some embodiments, each of the apertures 52 of the latch arm 50 and the bracket 80 may be formed with a larger diameter than the first pin 60. Ball bearing assemblies 75a and 76a may be received within the latch arm 50 and the bracket 80, respectively, to provide pivotable and relatively friction free contact between the first pin 60 and each of the latch arm 50 and bracket 80.
As best shown in
The constraining bracket 70 includes a second aperture 72 spaced from and parallel to the first aperture 71. The second aperture 72 receives a second pin 64 that is aligned parallel to the first pin 60 and extends from the bottom surface 70b (i.e. the surface pointing toward the latch arm 50) of the constraining bracket 70. The second pin 64 is rigidly mounted to the constraining bracket 70 with a spline, a keyed connection, a weld joint, or another suitable connection method to prevent relative movement between the two components. The second pin 64 extends through an arcuate slot 54 defined in the latch arm 50, which defines the potential range of relative pivoting between the latch arm 50 and the constraining bracket 70 and operator 44.
A spring 76 (or another suitable biasing member) is disposed within the internal volume 80a of the bracket 80 with a first end connected to the latch arm 50 and a second opposite end connected to the bracket 80 or another fixed portion of the door 30. The spring 76 is aligned with respect to the latch arm 50 to bias the latch arm 50 into the normal position (
The latch arm 50 includes a leg 55 that extends outwardly from the body of the latch arm 50 and out of the internal volume 80a of the bracket 80. The leg 55 normally extends generally perpendicularly from the internal surface 32 of the door 30 in the closed position. The leg 55 includes a foot 56 that extends from the leg 55 in a generally perpendicular manner. The foot 56 includes a chamfered edge 57 and a locking edge 58 that faces the body of the latch arm 50. The chamfered edge 57 faces generally away from the body of the latch arm 50 and forms an acute angle β with the locking edge 58 (as best shown in
As discussed above, the frame 20 includes an outer forward surface 22 that receives the hinged connection with the door 30 and provides a relatively hermetic and relatively low thermal conductive connection between the door 30 and the frame 20. The forward surface 22 of the frame 20 includes at least one cavity 26 which supports a vertically extending bar 28. The cavity 26 provides room for the foot 56 to enter therein and the locking edge 58 of the foot 56 to engage the back side of the bar 28 to prevent the door 30 from pivoting from the closed to the open position.
In some embodiments, the door 30 may include two latch mechanisms 40, with a first latch mechanism 40 positioned proximate the top edge 33 of the door 30 and the second latch mechanism 40 positioned proximate the bottom edge 34 of the door 30. In embodiments with two latch mechanisms 40 on a single door 30, the handle 90 is connected to the operator 44 of each latch mechanism 40, such that pivoting of the handle 90 with respect to the door 30 causes both latch mechanisms 40 to move consistently. The frame 20 includes a similar number of cavities 26 and bars 28 that are positioned to receive the foot 56 from each latch mechanism 40. In some embodiments, two or more doors 30 are pivotably mounted to the frame 20, wherein the frame 20 includes a suitable number of cavities 26 and bars 28 to engage the number of latch mechanisms 40 provided on the two or more doors 30.
In operation, the door 30 may operated in the following manner. When the operator desires to close the door 30 and substantially enclose the cooking volume 13, the operator pushes or pulls the handle 90 as necessary to pivot the door 30 toward contact with the frame 20. As the door 30 reaches the closed position, the chamfered edge 57 of the foot 56 of the latch arm 50 contacts the front surface of the bar 28. The contact between the chamfered edge 57 and the bar 28 causes the latch arm 50 to pivot in the direction Y due to the sliding contact established between the chamfered edge 57 (
As the latch arm 50 pivots with contact between the chamfered edge 57 and the bar 28, the slot 54 of the latch arm 50 translates with respect to the second pin 64 that is maintained stationary. Specifically, when the latch mechanism 40 is in its normal position, the second pin 64 contacts the forward end 54a of the slot 54 as urged by the spring 76. Because the latch arm 50 pivots in the direction Y independently of the handle 90, operator 44, and constraining bracket 70 (upon which the second pin 64 is fixed), the slot 54 moves with respect to the second pin 64 until the second pin 64 contacts the rear end 54b of the slot 54. At this position, the latch arm 50 is prevented from further pivoting in the direction Y unless the handle 90 is pivoted as well. The length of the slot 54 is sized to allow the latch arm 50 and the foot 56 to pivot sufficiently to clear the bar 28 upon contact between the chamfered edge 57 and the bar 28.
With sufficient sliding contact between the chamfered edge 57 and the bar 28 (which causes similar pivoting of the latch arm 50 in the direction Y) the foot 56 of the latch arm 50 moves free of the bar 28, allowing the inner surface 32 of the door 30 to contact the frame 20. After the foot 56 clears the bar 28, the biasing spring 76 urges the latch arm 50 to pivot in the opposite direction W until the foot 56 is positioned behind the bar 28. Specifically, the locking edge 58 of the foot 56 contacts the inner surface of the bar 28 (i.e. the surface facing the interior of the cavity 26) and prevents the door 30 from opening or pivoting away from the frame 20 by simply pulling outward on the door 30 or the handle 90.
When the user desires to pivot the door 30 to the open position, the user holds and pivots the handle 90 with respect to the door 30 in the direction W while pulling the handle 90 in the direction away from the door 30 (
With rotation of the constraining bracket 70, the second pin 64 pivots through a similar arc and urges the latch arm 50 to similarly pivot in the direction Y due to the contact between the second pin 64 and the forward end 54a of the slot 54. As the latch arm 50 pivots in the direction Y, the locking edge 58 of the foot 56 slides past the bar 28 until the foot 56 no longer contacts the bar 28. When the foot 56 clears the bar 28, the door 30 becomes free to be pulled from the frame 20 by the handle 90. After the door 30 is pivoted away from the frame 20, the handle 90 may be released, which allows the latch bar 50 to pivot in the direction W under the biasing force of the spring 76. The leg 55 of the latch arm 50 is retained substantially perpendicular to and extending from the door 30 due to the contact between the first surface 45a of the operator 44 and the first shoulder 86a.
While the preferred embodiments have been described, it should be understood that the disclosure is not so limited and modifications may be made without departing from the scope of the disclosure. The scope of the invention is defined by the appended claims, and all devices that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.
