Patent Publication Number: US-10309423-B2

Title: Mechanically actuated safety compliant fan finger guard structures and methods

Description:
BACKGROUND 
     The present application relates to guard structures, and more particularly to a guard structure that complies with safety features and guards a fan. 
     Fans are used in conjunction with various electrical equipment that benefit from the movement of heat and/or air from their location. Perforations to cover the fan, thereby preventing a person from having their clothing or a portion of their bodies contact the blades of the fan, are a safety requirement. The specified dimensions for the size of perforations or openings are found in safety standards, such as International Electrotechnical Commission (IEC) 60950. 
     These safety standards include size of opening requirements for fan enclosures, which cover one or more surfaces of a fan. 
     During operation, fan enclosures with larger openings increase airflow and increase the ability of the fan to disperse heat because less material is blocking air flow from the fan. But, there is a limit as to how large the openings can be so as to still satisfy the safety requirements. 
     Thus, a guard structure for a fan that is safety compliant and also allows for increased air flow when the fan is in use is desired. 
     SUMMARY 
     In one embodiment, a fan guard is provided. The fan guard includes a first lattice, the first lattice comprising a first lattice protrusion, a second lattice, the second lattice comprising a second lattice protrusion and an inclined portion, a catch, a tensioning element, a first end of the tensioning element operably attached to the first lattice protrusion, a second end of the tensioning element operably attached to the second lattice protrusion, the tensioning element applying a rotational force to the second lattice in a first direction, and a bezel. The bezel includes a bezel extension that extends substantially perpendicularly from a face of the bezel, wherein the bezel extension is configured to rotate the catch and an inclined plane extending from the face of the bezel, the inclined plane configured to contact the inclined portion of the second lattice and configured to apply a rotational force to the second lattice in a second direction, moving the second lattice from an alternate position to a first position. 
     In another embodiment, a fan guard is provided. The fan guard includes a first lattice, the first lattice comprising a first lattice protrusion, a second lattice, the second lattice comprising a second lattice protrusion and a second lattice projection, a catch, a tensioning element, a first end of the tensioning element operably attached to the first lattice protrusion, a second end of the tensioning element operably attached to the second lattice protrusion, the tensioning element applying a rotational force to the second lattice in a first direction, a scissor arm, a first end of the scissor arm operably attached to the first lattice, a second end of the scissor arm operably attached to the second lattice projection, and a bezel. The bezel includes a first bezel extension that extends substantially perpendicularly from a face of the bezel, wherein the first bezel extension is configured to rotate the catch, and a second bezel extension that extends substantially perpendicularly from the face of the bezel, wherein the second bezel extension is configured to contact and rotate an angled portion of the scissor arm to apply a rotational force to the second lattice in a second direction moving the second lattice from an alternate position to a first position. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a front view of a fan guard of an embodiment of the application, in a first configuration. 
         FIG. 2  is a front view of a fan guard of an embodiment of the application, in a second configuration. 
         FIG. 3  is a rear view of a fan guard of an embodiment of the application, in a second configuration. 
         FIG. 4  is a magnified view of a portion of  FIG. 3 . 
         FIG. 5  is a rear view of a fan guard of an embodiment of the application in a first configuration. 
         FIG. 6  is a magnified view of a portion of  FIG. 5 . 
         FIG. 7  is a magnified view of a rear portion of a bezel. 
         FIG. 8  is a magnified view of a rear portion of a bezel, including a first and second lattice. 
         FIGS. 9A-9C  are comparative side views and magnified views of a rear portion of a bezel, including a first and second lattice. 
         FIG. 10  is a front view of a fan guard of an embodiment of the application, in a first configuration. 
         FIG. 11  is a front view of a fan guard of an embodiment of the application, in a second configuration. 
         FIG. 12  is a rear view of a fan guard of an embodiment of the application, in a second configuration. 
         FIG. 13  is a magnified view of a portion of  FIG. 12 . 
         FIG. 14  is a rear view of a fan guard of an embodiment of the application in a first configuration. 
         FIG. 15  is a magnified view of a portion of  FIG. 14 . 
         FIGS. 16A and 16B  are comparative top views of an embodiment of a bezel, including a first and second lattice. 
         FIG. 17  is a front view of fan assemblies that can be used in conjunction with the fan guards of the present disclosure covered by a bezel. 
         FIG. 18  is a front view of fan assemblies that can be used in conjunction with the fan guards of the present disclosure not covered by a bezel. 
     
    
    
     DETAILED DESCRIPTION 
     The present application will now be described in greater detail by referring to the following discussion and drawings that accompany the present application. It is noted that the drawings of the present application are provided for illustrative purposes only and, as such, the drawings are not drawn to scale. It is also noted that like and corresponding elements are referred to by like reference numerals. 
     In the following description, numerous specific details are set forth, such as particular structures, components, materials, dimensions, processing steps and techniques, in order to provide an understanding of the various embodiments of the present application. However, it will be appreciated by one of ordinary skill in the art that the various embodiments of the present application may be practiced without these specific details. In other instances, well-known structures or processing steps have not been described in detail in order to avoid obscuring the present application. 
     It will be understood that when an element as a layer, region or substrate is referred to as being “on” or “over” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” or “directly over” another element, there are no intervening elements present. It will also be understood that when an element is referred to as being “beneath” or “under” another element, it can be directly beneath or under the other element, or intervening elements may be present. In contrast, when an element is referred to as being “directly beneath” or “directly under” another element, there are no intervening elements present. 
     In the discussion and claims herein, the term “about” indicates that the value listed may be somewhat altered, as long as the alteration does not result in nonconformance of the process or structure to the illustrated embodiment. For example, for some elements the term “about” can refer to a variation of ±0.1%, for other elements, the term “about” can refer to a variation of ±1% or ±10%, or any point therein. 
     As used herein, the term “substantially”, or “substantial”, is equally applicable when used in a negative connotation to refer to the complete or near complete lack of an action, characteristic, property, state, structure, item, or result. For example, a surface that is “substantially” flat would either be completely flat, or so nearly flat that the effect would be the same as if it were completely flat. 
     As used herein terms such as “a”, “an” and “the” are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. 
     As used herein, terms defined in the singular are intended to include those terms defined in the plural and vice versa. 
     Reference herein to any numerical range expressly includes each numerical value (including fractional numbers and whole numbers) encompassed by that range. To illustrate, reference herein to a range of “at least 50” or “at least about 50” includes whole numbers of 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, etc., and fractional numbers 50.1, 50.2 50.3, 50.4, 50.5, 50.6, 50.7, 50.8, 50.9, etc. In a further illustration, reference herein to a range of “less than 50” or “less than about 50” includes whole numbers 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, etc., and fractional numbers 49.9, 49.8, 49.7, 49.6, 49.5, 49.4, 49.3, 49.2, 49.1, 49.0, etc. In yet another illustration, reference herein to a range of from “5 to 10” includes whole numbers of 5, 6, 7, 8, 9, and 10, and fractional numbers 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, etc. 
     As used herein the term “lattice” is used in a broad sense to refer to a mesh-like structure having one or more elements that extend across a frame to form smaller openings, such as in a grate, a grid, a grill or a web of elements. 
     Referring first to  FIG. 1 , there is illustrated a general, perspective, front view of one embodiment of a fan apparatus, the fan apparatus including a fan guard  1 , a circular fan housing  9  and a bezel  11  that separates users from the fan guard  1  and a fan within fan housing  9 . The fan guard  1  includes a first lattice  2  and a second lattice  4 . First lattice  2  includes a number of first crosspieces  3 , in an annular pattern in this embodiment. Second lattice  4  includes a number of second crosspieces  5 , in an annular pattern in this embodiment. In other embodiments, the first crosspieces  3  and second crosspieces  5  can be the same, or different, and can be in any pattern that is suitable for the flow of air therethrough. The fan guard  1  can be placed in any suitable frame or structure to maintain the position of the fan guard  1  between a user and a rotating fan shaft (with blades attached thereto) within the fan housing  9 . 
     In this embodiment, the pattern of first crosspieces  3  and second crosspieces  5  remains substantially the same in the four separate portions containing the crosspieces across the first lattice  2  and second lattice  4 . In other embodiments, the pattern of first crosspieces  3  and second crosspieces  5  can change, such as by having a larger or smaller opening or a thicker or thinner crosspiece, as the distance increases from a center of the fan guard  1 . 
     The first lattice  2  and the second lattice  4  can be formed of the same, or different materials from each other. These materials can be any suitable material that can maintain a structural form, such as plastics, metals, carbon based materials, and mixtures thereof. 
     In this embodiment the bezel  11  is shown as having a honeycomb pattern of openings, but in other embodiments, bezel  11  can include any pattern that is suitable for the flow of air therethrough. Bezel  11  also includes a bezel extension  13  (further discussed and shown in the following figures) that extends substantially perpendicularly from the rear of bezel  11 I and through an opening  7  in the first lattice  2 . 
     When the bezel  11  is removed, the second lattice  4  is in the alternate position, as seen in  FIG. 1 . Openings between both the first crosspieces  3  and openings between the second crosspieces  5  are smaller than or equal to the area proscribed in safety standards, such as IEC 60950, so as to not allow a person&#39;s finger to pass through both the first lattice  2  and the second lattice  4  to contact moving fan blades within fan housing  9 . In other embodiments the area of one or both of the first lattice  2  and the second lattice  4  near the center of fan guard  1  can include a different pattern of crosspieces, resulting in larger openings, or can be substantially covered by a guard or plate to not allow access by a user. 
     Within the fan housing  9 , a fan shaft and fan blades can be contained. This fan housing  9  is shown for illustrative purposes and is not limited to the size, orientation or location it is shown in. Also for illustrative purposes, an arrow is shown indicating the flow of air from the interior of the fan housing  9  towards the first lattice  2  and second lattice  4 . In other embodiments, the flow of air can be in the opposite direction, or at any angle that passes air through the first lattice  2  and the second lattice  4 . 
     Referring to  FIG. 2 , there is illustrated a general, front view of one embodiment of the fan guard  1 . In this view, second lattice  4  has been rotated to a position directly behind the first lattice  2  and hidden from view (a first position of second lattice  4 ). In this view, first crosspieces  3  of the first lattice  2  substantially align with second crosspieces  5  of the second lattice  4 . The bezel  11  is shown as substantially transparent, and with portions removed, for illustrative purposes. In this view, bezel  11  is moved into an operational position (further discussed in reference to figures below) by pressing the bezel  11  in the direction of arrows A. By this pressing of bezel  11 , bezel extension  13  extends through the opening  7  and allows for rotation of the second lattice  4  into the configuration shown in  FIG. 2 . 
     The positional change between  FIGS. 1 and 2 , between the first position of the second lattice  4  and the alternate position, is shown and described as a rotational change along the X-Y axes, but in other embodiments, this positional change can be due to any rotational movement along any plane. 
     Further, when the second lattice  4  is in the first position, as seen in  FIG. 2 , the openings between both the first crosspieces  3  and openings between the second crosspieces  5  are larger than the area proscribed in safety standards such as IEC 60950, so as to allow a larger flow of air to pass through both the first lattice  2  and the second lattice  4 . A user cannot touch moving fan blades in this configuration due to the bezel being installed. 
     Referring to  FIG. 3 , there is illustrated a general, rear view of one embodiment of the fan guard  1 . In this view, the second lattice  4  is in a first position, having rotated according to the direction of arrow C. Also in this view it can be seen that bezel extension  13  has extended through opening  7  and has contacted a catch  15 . In some embodiments, such as that shown in  FIG. 3 , bezel extension  13  can include a tapered face that contacts the catch  15  and causes the catch  15  to rotate according to the direction of arrow B about a pivot (shown in more detail in  FIG. 4  below). In other embodiments, bezel extension  13  can extend a shorter distance, or no distance, from the bezel  11 , and can include a magnetic force that interacts with a magnetic force of the catch  15  to cause a rotation of the catch  15 . 
     A tensioning element  17 , such as a spring, is affixed to a first lattice protrusion  16  on a first end, and a second end of the tensioning element  17  can be affixed to a second lattice protrusion  19 . In  FIG. 3 , tensioning element  17  is under tension and upon removal of bezel extension  13 , will cause the second lattice  4  to rotate opposite of arrow C, into the alternate position shown in  FIG. 1 . Second lattice  4  is operably affixed to first lattice  2  and rotates in comparison to the first lattice  2  about a lattice pivot point  25 . 
     A first lattice extension  21  extends from the first lattice  2 , contacting a second lattice extension  23  upon rotation of second lattice  4  opposite of arrow C to stop the rotation of second lattice  4  upon removal of bezel  11 , as shown in  FIG. 5  below. 
     A detailed view of the catch  15  is shown in  FIG. 4  (in the configuration shown in  FIG. 3 ), with tensioning element  17  removed for illustrative purposes. The catch  15  rotates about the first lattice protrusion  16  in the direction of arrow B (same direction as arrow B of  FIG. 3 ). In this embodiment the first lattice protrusion  16  is shown as a pivot point for catch  15 , but in other embodiments, the first lattice protrusion  16  can be separate from the pivot point for the catch  15  and can be in a different suitable location. 
     Catch  15  is caused to rotate in the direction of arrow B through bezel extension  13  contacting catch receiving protrusion  18 . 
     Referring to  FIG. 5 , there is illustrated a general, rear view of one embodiment of the fan guard  1 , with bezel  11  moved away from fan guard  1  in the direction of arrow D. As bezel  11  moves in the direction of arrow D, the bezel extension  13  withdraws through opening  7 , allowing for the catch  15  to rotate in the direction of arrow F due to the contraction of tensioning element  17 . 
     In this view, with the second lattice  4  in the alternate position, second lattice  4  has rotated in the direction of arrow E (as compared to the view in  FIG. 3 ) about lattice pivot point  25  due to the contraction of tensioning element  17 . In the alternate position the first lattice extension  21  contacts the second lattice extension  23  and restricts further rotation of the second lattice  4 . 
     A detailed view of the catch  15  is shown in  FIG. 6  (in the configuration shown in  FIG. 5 ), with tensioning element  17  removed for illustrative purposes. The catch  15  rotates about the first lattice protrusion  16  in the direction of arrow F (same direction as arrow F of  FIG. 5 ). Catch  15  is caused to rotate in the direction of arrow F due to the contraction of tensioning element  17  (shown in  FIG. 5 ) upon removal of bezel  11 . As the catch  15  rotates in the direction of arrow F, a substantially hook-shaped protrusion  27  of the catch  15  extends around at least a portion of second lattice protrusion  19 . When the substantially hook-shaped protrusion  27  is in the configuration shown in  FIG. 6 , rotation of the second lattice  4  in a direction opposite of arrow E (of  FIG. 5 ) via human interaction with an appendage or tool is restricted or prevented. 
     The operation of causing the second lattice  4  to rotate from the alternate position (shown in  FIGS. 1 and 5 ) to the first position (shown in  FIGS. 2 and 3 ) is discussed below beginning with  FIG. 7 . 
       FIG. 7  is a magnified view of a central area of the bezel  11 , specifically, the face of the bezel  11  that is in contact with the first lattice  2  in  FIG. 3 . In  FIG. 7 , the bezel  11  includes at least one (in this figure two) helical, inclined planes  29  and, optionally, at least one (in this figure two) bezel protrusions  31 . The optional bezel protrusions  31  can aid in placement of the bezel  11  against the lattices (as in the direction of arrow A in  FIG. 2 ), and can also restrict rotation of the second lattice  4 , as desired. 
       FIG. 8  is a magnified view of the central area of bezel  11 , illustrating the interaction of the bezel  11 , first lattice  2  and second lattice  4 . As can be seen in  FIG. 8 , the second lattice  4  includes two inclined portions  33 , but in other embodiments one inclined portion can be included if one inclined plane  29  is included. As bezel  11  is moved (in the direction of arrow A of  FIG. 2 ) the inclined planes  29  impact the inclined portions  33  and cause rotation of the second lattice  4  in a clockwise direction as shown in  FIG. 8 . In this embodiment the rotation is in a clockwise direction, but in other embodiments, the angle of the inclined planes  29  and inclined portions  33  can be modified for an opposite rotation. 
       FIGS. 9A-9C  illustrate a method of applying the bezel  11 , and how that bezel  11  interacts with the first lattice  2  and the second lattice  4 . 
     In  FIG. 9A , the second lattice  4  is in the alternate position. As seen in the upper portion of  FIG. 9A , the bezel  11  is not in place, but is now moving in the lateral direction of the arrow G towards the fan guard  1 . Bezel  11  can be moved physically by a user and/or bezel  11  can be moved through a solenoid or other suitable actuator that is capable of moving bezel  11 . In this configuration, the tensioning element  17  is under little or no tension (as shown in more detail in  FIG. 5 ). 
     As can be seen in  FIG. 9A , the bezel extension  13  extends a further distance from the bezel  11  than inclined planes  29 . This difference in distance allows for the bezel extension  13  to contact the catch  15 , thus disengaging the catch from the second lattice protrusion  19  prior to the inclined planes  29  contacting the inclined portions  33  of the second lattice  4 . 
     In  FIG. 9B , the second lattice  4  is transitioning between the alternate position and the first position. In this transition, the bezel extension  13  has contacted and released the catch  15 , and the inclined portions  33  of the second lattice  4  begin to contact the inclined planes  29  of bezel  11 . As the bezel extension  13  contacts the catch  15 , specifically the catch receiving protrusion  18 , the catch  15  begins to rotate in the direction of arrow B in  FIG. 4 . As the bezel  11  moves further in the direction of arrow G, the inclined portions  33  further contact the inclined planes  29 , causing the second lattice  4  to rotate in a clockwise direction. This linear motion of bezel  11 , in the direction of the arrow, is translated to a rotational movement of the second lattice  4  through contact of the inclined portions  33  and the inclined planes  29 . 
     In this configuration, the tensioning element  17  begins to receive tension by the rotation of the second lattice  4 . 
     In  FIG. 9C , the second lattice  4  has been moved to the first position. In this configuration, the tensioning element  17  is under tension (as shown in more detail in  FIG. 3 ) and the bezel  11  is contacting (or is in close proximity to) the first lattice  2 . In this configuration portions of the second lattice  4  can come into rotational contact with the bezel protrusions  31 , which can provide a further mechanism to stop the rotation of the second lattice  4  at the first position. 
     Referring first to  FIG. 10 , there is illustrated a general, perspective, front view of another embodiment of a fan apparatus, the fan apparatus including a fan guard  201 , a circular fan housing  9  and a bezel  211  that separates users from the fan guard  201  and a fan within fan housing  9 . The fan guard  201  includes a first lattice  202  and a second lattice  204 . First lattice  202  includes a number or first crosspieces  203 , in an annular pattern in this embodiment. Second lattice  204  includes a number of second crosspieces  205 , in an annular pattern in this embodiment. In other embodiments, the first crosspieces  203  and second crosspieces  205  can be the same, or different, and can be in any pattern that is suitable for the flow of air therethrough. The fan guard  201  can be placed in any suitable frame or structure to maintain the position of the fan guard  201  between a user and a rotating fan shaft (with blades attached thereto) within the fan housing  9 . 
     In this embodiment, the pattern of first crosspieces  203  and second crosspieces  205  remains substantially the same in the four separate portions containing the crosspieces across the first lattice  202  and second lattice  204 . In other embodiments, the pattern of first crosspieces  203  and second crosspieces  205  can change, such as by having a larger or smaller opening or a thicker or thinner crosspiece, as the distance increases from a center of the fan guard  201 . 
     In this embodiment a scissor arm  215  extends from a first lattice extension  223  to operably connect to the second lattice  204 , which is shown more fully below. The scissor arm  215  is comprised of a plurality of operably connected links  216  that can rotate in reference to one another and in reference to the fan guard  201 . When the second lattice  204  is in an alternate position (as shown in  FIG. 10 ), the scissor arm  215  is extended, as shown in  FIG. 10 . When the second lattice  204  is in a first position (as shown in  FIG. 11 ), the scissor arm  215  is retracted. 
     The first lattice  202  and the second lattice  204  can be formed of the same, or different materials from each other. These materials can be any suitable material that can maintain a structural form, such as plastics, metals, carbon based materials, and mixtures thereof. 
     In this embodiment the bezel  211  is shown as having a honeycomb pattern of openings, but in other embodiments, bezel  211  can include any pattern that is suitable for the flow of air therethrough. Bezel  211  also includes a first bezel extension  213  (further discussed and shown in the following figures) that extends substantially perpendicularly from the rear of bezel  211  and through a first opening  207  in the first lattice  202 . Bezel  211  also includes a second bezel extension  214  (further discussed and shown in the following figures) that extends substantially perpendicularly from the rear of bezel  211  and through a second opening  209  in the first lattice  202 . 
     When the bezel  211  is removed, the second lattice  204  is in the alternate position, as seen in  FIG. 10 . Openings between both the first crosspieces  203  and openings between the second crosspieces  205  are smaller than or equal to the area proscribed in safety standards, such as IEC 60950, so as to not allow a person&#39;s finger to pass through both the first lattice  202  and the second lattice  204  to contact moving fan blades within fan housing  9 . In other embodiments the area of one or both of the first lattice  202  and the second lattice  204  near the center of fan guard  201  can include a different pattern of crosspieces, resulting in larger openings, or can be substantially covered by a guard or plate to not allow access by a user. 
     Within the fan housing  9 , a fan shaft and fan blades can be contained. This fan housing  9  is shown for illustrative purposes and is not limited to the size, orientation or location it is shown in. Also for illustrative purposes an arrow indicating the flow of air from the interior of the fan housing  9  towards the first lattice  202  and second lattice  204 . In other embodiments, the flow of air can be in the opposite direction, or at any angle that passes air through the first lattice  202  and the second lattice  204 . 
     Referring to  FIG. 11 , there is illustrated a general, front view of one embodiment of the fan guard  201 . In this view, second lattice  204  has been rotated to a position directly behind the first lattice  202  and hidden from view (a first position of the second lattice  204 ). In this view, first crosspieces  203  of the first lattice  202  substantially align with second crosspieces  205  of the second lattice  204 . The bezel  211  is shown as substantially transparent, and with portions removed, for illustrative purposes. In this view, bezel  211  is moved into an operational position (further discussed in reference to figures below) by pressing the bezel  211  in the direction of arrows C. This pressing of bezel  211  causes first bezel extension  213  to extend through the first opening  207  and allows for rotation of the second lattice  204  into the configuration shown in  FIG. 11 . This pressing of bezel  211  also causes the second bezel extension  214  to extend through the second opening  209  and contact a portion of scissor arm  215 , rotating the second lattice  204  into the configuration shown in  FIG. 11 . 
     The positional change between  FIGS. 10 and 11 , between the first position and the alternate position, is shown and described as a rotational change along the X-Y axes, but in other embodiments, this positional change can be due to any rotational movement along any plane. 
     Further, when the second lattice  204  is in the first position, as seen in  FIG. 11 , the openings between both the first crosspieces  203  and openings between the second crosspieces  205  are larger than the area proscribed in safety standards such as IEC 60950, so as to allow a larger flow of air to pass through both the first lattice  202  and the second lattice  204 . A user cannot touch moving fan blades in this configuration due to the bezel being installed. 
     Referring to  FIG. 12 , there is illustrated a general, rear view of one embodiment of the fan guard  201 . In this view, the second lattice  204  is in a first position, having rotated according to the direction of arrow D. Also in this view it can be seen that first bezel extension  213  has extended through the first opening  207  and has contacted a catch  15 . In some embodiments, such as that shown in  FIG. 12 , first bezel extension  213  can include a tapered face that contacts the catch  15  and causes the catch  15  to rotate according to the direction of arrow A about a pivot (shown in more detail in  FIG. 13  below). 
     Also in this view, it can be seen that the second bezel extension  214  has extended through the second opening  209  and has contacted a portion of the scissor arm  215 . In some embodiments, such as that shown in  FIG. 12 , the second bezel extension  214  can include a tapered face that contacts an angled portion  217  of the scissor arm  215  and causes the scissor arm  215  to retract in the direction of arrow B. The scissor arm is operably connected on a first end to the first lattice extension  223  and operably connected on a second end to a second lattice projection  221 . 
     A tensioning element  17 , such as a spring, is affixed to a first lattice protrusion  16  on a first end, and a second end of the tensioning element  17  can be affixed to a second lattice protrusion  219 . In  FIG. 12 , tensioning element  17  is under tension, and upon removal of first bezel extension  213 , will cause the second lattice  204  to rotate opposite of arrow D, into the alternate position shown in  FIG. 10 . Second lattice  204  is operably affixed to first lattice  202  and rotates in comparison to the first lattice  202  about a lattice pivot point  225 . 
     A detailed view of the catch  15  is shown in  FIG. 13  (in the configuration shown in  FIG. 12 ), with tensioning element  17  removed for illustrative purposes. The catch  15  rotates about first lattice protrusion  16  in the direction of arrow A (same direction as arrow A of  FIG. 12 ). In this embodiment the first lattice protrusion  16  is shown as a pivot point for catch  15 , but in other embodiments, the first lattice protrusion  16  can be separate from the pivot point for the catch  15  and can be in a different suitable location. Catch  15  is caused to rotate in the direction of arrow A through first bezel extension  213  contacting catch receiving protrusion  18 . 
     Referring to  FIG. 14 , there is illustrated a general, rear view of one embodiment of the fan guard  1 , with bezel  211  moved away from fan guard  201  in the direction of arrows E. As bezel  211  moves in the direction of arrows E, the second bezel extension  214  withdraws through the second opening  209 , allowing for the scissor arm  215  to extend in the direction of arrow G due to the contraction of tensioning element  17 . Subsequently, as bezel  211  continues moving in the direction of arrows E, the first bezel extension  213  withdraws through the first opening  207 , allowing for the catch  15  to rotate in the direction of arrow H due to the contraction of tensioning element  17 . 
     In this view, with the second lattice  204  in the alternate position, second lattice  204  has rotated in the direction of arrow F (as compared to the view in  FIG. 12 ) about lattice pivot point  225 . The second lattice  204  has rotated due to the contraction of tensioning element  17 . 
     A detailed view of the catch  15  is shown in  FIG. 15  (in the configuration shown in  FIG. 14 ), with tensioning element  17  removed for illustrative purposes. The catch  15  rotates about the first lattice protrusion  16  in the direction of arrow H (same direction as arrow H of  FIG. 14 ). Catch  15  is caused to rotate in the direction of arrow H due to the withdrawal of first bezel extension  213 . As the catch  15  rotates in the direction of arrow H, a substantially hook shaped protrusion  27  of the catch  15  extends around at least a portion of second lattice protrusion  219 . When the substantially hook shaped protrusion  27  is in the configuration shown in  FIG. 15 , rotation of the second lattice  204  in a direction opposite of arrow F (of  FIG. 14 ) via human interaction with an appendage or tool is restricted or prevented. 
     The operation of causing the second lattice  204  to rotate from the alternate position (shown in  FIGS. 10 and 14 ) to the first position (shown in  FIGS. 11 and 12 ) is discussed below in conjunction with  FIGS. 16A and 16B . 
       FIG. 16A  is a top view of the fan guard  201  when the second lattice  204  is in the alternate position. As can be seen in  FIG. 16A , in this embodiment, the angled portion  217  of scissor arm  215  is further recessed inside fan guard  201  as compared to the catch  15 . Thus, first bezel extension  213  contacts and rotates catch  15  before second bezel extension  214  contacts angled portion  217  of scissor arm  215  when the bezel  211  is moving in the direction of the arrows in  FIG. 16A . Also, after the bezel  211  is moved fully towards the fan guard  201  and withdrawn (opposite of arrows in  FIG. 16A ) the second bezel extension  214  withdraws from contacting the angled portion  217  of the scissor arm  215  prior to the first bezel extension  213  withdrawing from contacting the catch  15  (so that the substantially hook-shaped protrusion  27  engages the second lattice protrusion  219  as shown in  FIG. 15 ). 
     In other embodiments the second bezel extension  214  and the first bezel extension  213  can be substantially the same length. 
     In this embodiment, scissor arm  215  is operably connected to the second lattice projection  221  through a connector  222 . Connector  222  can be any suitable shape that can substantially translate the rotation of links  216  to a substantially tangential motion of the second lattice projection  221 . 
       FIG. 16B  is a top view of the fan guard  201  when the second lattice  204  is in the first position. In this configuration the second lattice extension  214  has contacted the angled portion  217  of the scissor arm  215  and caused the angled portion  217  of the scissor arm  215  to rotate counter-clockwise, and retract scissor arm  215  in the direction of the arrow of  FIG. 16B . This retraction of scissor arm  215  also causes the tensioning element  17  to expand. 
     The methods and devices of the present disclosure will be better understood by reference to the following examples, which are provided as exemplary of the disclosure and not by way of limitation. 
     Example 1 
     When fan guard  1  is in the alternate position, as shown in  FIG. 1 , the radial areas formed by the openings of both the first lattice  2  and the second lattice  4  (white areas between the crosspieces of both the first lattice  2  and the second lattice  4 ) combine to an open area of about 3,141 mm 2 . 
     When fan guard  1  is in the first position, as shown in  FIG. 3 , the radial areas formed by the openings of both the first lattice  2  and the second lattice  4  (white areas between the crosspieces of the first lattice  2  and the second lattice  4 ) combine to an open area of about 3,747 mm 2 . Although  FIG. 3  is shown as including a bezel  11 , the following calculations are made without the inclusion of a bezel. 
     To determine the difference in pressure drop between the two second lattice positions, the following formula was used: 
     
       
         
           
             
               Δ 
               ⁢ 
               
                   
               
               ⁢ 
               p 
             
             = 
             
               
                 
                   k 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   ρ 
                 
                 2 
               
               ⁢ 
               
                 v 
                 2 
               
             
           
         
       
     
     Wherein p is pressure, k is the minor loss coefficient, ρ is the air density and ν is air velocity. 
     Next, the following equations were solved to determine the difference in pressure drop of air passing through the open area shown in  FIG. 1  (A 2 ) as compared to the air passing through the open area shown in  FIG. 3  (A 1 ). 
     
       
         
           
             
               
                 
                   v 
                   = 
                   
                     
                       
                         A 
                       
                       ⇒ 
                       
                         Δ 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         p 
                       
                     
                     = 
                     
                       
                         
                           k 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           ρ 
                         
                         2 
                       
                       ⁢ 
                       
                         
                           ( 
                           
                             A 
                           
                           ) 
                         
                         2 
                       
                     
                   
                 
               
             
             
               
                 
                   
                     ( 
                     
                       
                         Δ 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           p 
                           1 
                         
                       
                       
                         Δ 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           p 
                           2 
                         
                       
                     
                     ) 
                   
                   = 
                   
                     
                       A 
                       2 
                       2 
                     
                     
                       A 
                       1 
                       2 
                     
                   
                 
               
             
             
               
                 
                   
                     
                       Δ 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         p 
                         1 
                       
                     
                     
                       Δ 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         p 
                         2 
                       
                     
                   
                   = 
                   
                     
                       
                         
                           ( 
                           
                             3141 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               mm 
                               2 
                             
                           
                           ) 
                         
                         2 
                       
                       
                         
                           ( 
                           
                             3747 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               mm 
                               2 
                             
                           
                           ) 
                         
                         2 
                       
                     
                     = 
                     0.703 
                   
                 
               
             
           
         
       
     
     Wherein   is constant volume flow and A is area. 
     As can be seen, the pressure drop of air passing through the open area shown in  FIG. 1  (A 1 ) as compared to the air passing through the open area shown in  FIG. 3  (A 2 ) is about 70.3%. This pressure drop is indicative of an increased airflow when the second lattice  4  of fan guard  1  is in the first position shown in  FIG. 3 . Due to a decrease in pressure, fan speeds can be decreased to achieve a similar air flow to the flow when the second lattice  4  is in the alternate position. This reduction in fan speed can reduce overall noise of a fan, reduce energy consumption of the fan, and prolong the life of the fan. 
     Example 2 
     A front view of five individual fan assemblies, which can be used in conjunction with the fan guards described above, is shown in  FIG. 17 . In  FIG. 17 , a bezel  120  (honeycomb structure) is shown as covering five fan assemblies and separates the fan blades of each fan assembly from where the user can access the covered fan blades. With the bezel  120  installed, the fan guard would be in the state shown in  FIGS. 3 and 12 . This bezel  120  can be composed of features shown on bezels  11  and/or  211  as discussed above, including one or more bezel extensions and/or central areas to interact with each of the five individual fan assemblies. The bezel prevents a user from reaching through the larger fan openings to touch moving fan blades in this configuration. 
     A front view of the five individual fan assemblies of  FIG. 17  are shown again in  FIG. 18 , with the bezel  120  removed, resulting in the fan guard being placed in the state shown in  FIGS. 1 and 10 . 
     In this view each fan assembly includes a barrier  122 , which is between where the user can access and the fan blades  124 . In embodiments of the present disclosure, each of these barriers  122  can be removed and replaced with the fan guard  1  or fan guard  201  as described above. 
     While the present application has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details may be made without departing from the spirit and scope of the present application. It is therefore intended that the present application not be limited to the exact forms and details described and illustrated, but fall within the scope of the appended claims.