Flame simulator for use in an electric heater

Apparatus is provided for projecting light to simulate flames on a screen for use in an electric fireplace with an imitation flame display. The apparatus comprises a hollow cylinder enclosing an interior region, the cylinder being rotatable about an axis of the cylinder and having a sidewall with an exterior surface and a non-reflective interior surface with apertures through the sidewall. A light source in the interior region is operated to cause light to be transmitted through the apertures onto the screen to simulate moving flames when the cylinder is rotated. This arrangement provides an improved imitation flame display on the screen. When incorporated into an electric fireplace, the apparatus provides a pleasing illusion of active, dancing flames adjacent an artificial log set.

FIELD OF THE INVENTION

The present invention relates generally to electric heaters with imitation flame displays, and more particularly, to a flame simulating apparatus for generating the appearance of flames in such an imitation fireplace electric heater.

BACKGROUND OF THE INVENTION

There exist electric fireplaces flame simulators in which light from a light source is projected up through a rotating cylinder, through a coloured filter screen and onto a reflective screen. There also exist flame simulators in which light from a light source is reflected from a metallic strip onto a rotating set of coloured metallic strips and then projected through a flame effect element before being finally reflected from a mirror to an observer.

Our pending Canadian Patent application No. 2,459,788 filed Mar. 5, 2004, the disclosure of which is incorporated herein by reference, discloses a flame simulating apparatus for use in an electric fireplace to project imitation flames onto a screen of the fireplace.

Our pending Canadian application No. 2.459,849 filed Mar. 5, 2004, the disclosure of which is incorporated herein by reference, discloses a flame simulating apparatus with cooling features for use in an electric fireplace to display imitation flames on a screen.

SUMMARY OF THE INVENTION

The present invention provides an improved apparatus for projecting light to simulate flames on a screen, and an electric fireplace incorporating the apparatus to creates an interesting and pleasing imitation flame pattern visible on a screen within the fireplace.

Accordingly, the present invention provides apparatus for projecting light to simulate flames on a screen, the apparatus comprising:a hollow cylinder enclosing an interior region, the cylinder being rotatable about an axis of the cylinder and having a sidewall with an exterior surface and a non-reflective interior surface with apertures through the sidewall; anda light source in the interior region operable to cause light to be transmitted through the apertures onto the screen to simulate moving flames when the cylinder is rotated.

The apparatus is simple in structure for reliable operation and formed using inexpensive parts.

In a further aspect, the present invention provides an electric fireplace with imitation flames comprising:

an enclosure;

an electric heater unit within the enclosure;

a simulated fuel source within the enclosure; and

a flame simulation apparatus for generating the appearance of flames, the flame simulation apparatus comprising:

a light diffusing panel adjacent the simulated fuel source;

a flame effect mask positioned adjacent the light diffusing panel;

a hollow cylinder enclosing an interior region, the cylinder being rotatable about an axis of the cylinder and having a sidewall with an exterior surface and a non-reflective interior surface with apertures through the sidewall; and

a light source in the interior region operable to cause light to be transmitted through the apertures of the cylinder sidewall, past the flame effect mask for projection onto the light diffusing panel for display as simulated moving flames when the cylinder is rotated.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIGS. 1 and 2, there is shown apparatus2for projecting light to simulate flames on a screen according to a preferred embodiment of the present invention. As best shown in its assembled state inFIG. 2, the apparatus includes a hollow cylinder4enclosing an interior region6. The hollow cylinder is rotatable about an axis8of the cylinder. As best shown in the exploded view ofFIG. 1, hollow cylinder4is preferably formed as a modular structure that includes a pair of attached panels122and123which define the sidewall of the cylinder. A mounting frame20holds a motor121at one end that rotatably drives the hollow cylinder4for rotation about axis8. A motor drive rod124is inserted through frame end bracket125to engage with an end plate126of cylinder4. End plate126is connected to another end plate127by an array of retaining rods128,129,130and131. End plate127acts as a support for a light source160,161positioned within the interior region6of the cylinder. Retaining rods128,129130and131form a mounting system extending between end plates126and127for removably securing panels122and123between the end plates. When secured between end plates126and127, panels122and123form the sidewall of cylinder4to establish interior and exterior surfaces of the cylinder. The plurality of retaining rods preferably comprise a top flange retaining rod128, a bottom flange retaining rod129, and a pair of panel backing rods130and131. The cylinder sidewall is assembled by squeezing together the edges of panels122and123such that top flanges140and141on the edges are positioned adjacent a retaining channel143in top flange retaining rod128. Release of the edges results in the flanges being biased apart by the inherent resiliency of the panels to be retained in channel143. Similarly, bottom flanges144and145on the panels are squeezed and then released to fit within a retaining channel146formed in bottom flange retaining rod129. Panels122and123have their interior surfaces positioned over panel backing retaining rods130and131when the flanges are positioned in channels143and146to assist in maintaining the cylindrical shape of the panels.

Panels122and123are preferably formed from a thin resilient sheet material, such as thin sheet metal, that can be shaped into a pliable, semi-cylindrical configuration, and folded along its long edges to form top flanges140,141and bottom flanges144,145.

Still referring toFIGS. 1 and 2, a light source, preferably in the form of bulbs161and162retained in sockets162and163, is mounted to a light source rod150which is inserted through frame end bracket151of frame20along rotation axis8of cylinder4to position the light source within the interior of the cylinder. Bulb sockets162,163are attached to rod150by brackets164and165, respectively. Rod150is fixedly secured to frame20at end bracket151by collar152. Quiet and smooth rotation of cylinder4by motor121about axis8is achieved using a rotator bushing153that rotatably supports end plate127of the cylinder. As shown inFIG. 2, wires155to supply electrical power to bulbs161and162enter the interior6of cylinder4through aligned openings in end plate127, bushing153, end bracket151and collar152. It will be appreciated by a person skilled in the art that other arrangements to position a light source within the interior6of cylinder4are possible.

The above described panel mounting arrangement and the light source mounting scheme permit ready access to the bulbs within interior6of cylinder4to permit changing of bulbs in the event of a bulb failure.

Panels122and123forming the sidewall of cylinder6are formed with apertures91therethrough. Rotation of cylinder4by motor121causes the apertures to rotate about cylinder axis8. Light from light bulbs161and162, which are stationary within interior6of the cylinder, is transmitted through the moving apertures for display on a screen in order to create a simulation of moving and flickering flames.

It has been discovered the imitation flame display is enhanced if the interior surface of panels122and123are non-reflective or light absorbing. For example, in a preferred arrangement, the interior surfaces of panels122and123facing the interior6of cylinder4may be formed with a matte black surface. Such a surface can be created by applying a matte black paint to the interior panel surfaces. It will be apparent to one of skill in the art that other non-reflective or light absorbing surfaces may be used by forming the panels of non-reflective material or by applying other non-reflective coating to the interior surfaces of the panels. For example, the application of any dull, flat finish by painting or otherwise to the interior surface of the drum will create the necessary non-reflective surface as opposed to the use or application of a surface having a smooth, glossy finish with a shine or luster. It is also possible for the exterior panel surfaces to be non-reflective or light absorbing.

As best shown inFIG. 3, the apertures in panels122and123are preferably formed as curved, generally S-shaped perforations91or circular perforations97through the panels. The apertures are preferably stamped or molded in a pattern or array suitable for generating a flame display when projected onto a screen. In the illustrated embodiment ofFIG. 3, generally flattened S-shaped perforations91are arranged in rows93,94and95with the perforations in each row being offset or staggered from the perforations in an adjacent row. Circular perforations97are also formed in offset rows. Other aperture shapes and arrays of apertures are possible. The staggering of the perforations91tends to create a waved flickering effect as the cylinder rotates that better simulates real flames in the flame display.

The central zone100of each panel can be formed with more apertures than the end zones101of the panel to create a brighter central region with more imitation flames in the flame display. Alternatively, having brighter bulbs or a greater concentration of bulbs positioned in the central region of interior6of cylinder4, or a combination of both such arrangements will achieve the same effect of a brighter central region in the imitation flame display.

Referring toFIG. 4, the apparatus2for projecting light of the present invention is shown installed in an electric fireplace10designed to display imitation flames on a screen24.FIG. 4is a cross-sectional elevation view through the electric fireplace unit. Hollow cylinder4is mounted at the rear of an enclosure21behind a simulated fuel source22at the front of the enclosure, which is positioned in front of screen24. Simulated fuel source22comprises an artificial log or charcoal arrangement. Screen24comprises a translucent panel having a rear facing side26onto which moving flames are back-projected from apparatus2for viewing from a front facing side25. Simulated fuel source22and the front facing side25of screen24are viewable through a front window30of the fireplace enclosure21.

The front facing side25of screen24preferably has reflective properties such that a reflection of the simulated fuel source22may be seen on the front facing side25of screen24. A portion of the front facing side25may optionally feature a “brick” pattern of alternating substantially non-reflective portions and substantially reflective portions.

The rear facing side26is optionally coated or provided with a frosted coating or sheet (not shown) that causes the light to diffuse as it passes through screen24. Such a diffusion coating or sheet softens or blurs the edges of the imitation flames in the flare display.

Also mounted within fireplace enclosure21directly behind screen24is a flame effect mask32.FIG. 5provides a front view of the mask which is an opaque surface having a lower edge formed with generally triangular cut outs34. Mask32acts to block some of the light emitted by cylinder4to create a more realistic imitation flame display on screen24.

The arrangement of cylinder4, flame effect mask32and screen24is such that light38transmitted through the rotating apertures91of the hollow cylinder4and past the flame effect mask32is projected onto rear facing side26of screen for display on a front facing side25as simulated moving flames above artificial fuel source22.

Screen24comprises a light diffusing panel that can be made of molded plastic that is translucent but not transparent, in order to soften and diffuse the light that is projected through the perforations of cylinder4producing a variable glow that enhances the simulation of flames while at the same time preventing viewing of cylinder4through the panel.

The electric fireplace of the present invention as shown inFIG. 4can also incorporate a heater unit40comprising a conventional electrical heater44with heater coils46and a blower fan51for directing air past the coils. A second light source48can be positioned below artificial fuel source22to provide a glow of burning embers below the artificial logs or coals of the artificial fuel source.

The fireplace is fitted with other standard components such as an on-off switch, a thermostat, and an overheat control circuit which allow the fireplace to be assembled into a unit that is functional, heat-producing, controllable, and safe.

Although the present invention has been described in some detail by way of example for purposes of clarity and understanding, it will be apparent that certain changes and modifications may be practised within the scope of the appended claims.