Heavy-Duty Plastic Picture Hanger Having Dual-Hooks And Hook-Above-Nail Arrangements

Abstract

Present invention discloses a heavy-duty plastic hanger that has both dual-hooks and hook-above-nail arrangements, and offers a 50 lb. or 70 lb. weight load capacity with two or three 3d penny size finish nails anchoring the hanger onto drywall at 15 degree incline angle.

Description

BACKGROUND OF THE INVENTION

Now day, user commonly uses a pair of metal hangers to hang a large picture frame on wall. Before hanging the picture frame, user needs to adopt a leveling tool (i.e. spirit level) to mark a horizontal line on wall, and then anchor the metal hangers along the horizontal line. After hanging the picture frame, user needs to take time and effort to adjust picture frame to a level and balance position. This is because picture frame can't be hung in level and balance if its weight center (i.e. center line) is not positioned nearby the center location between hangers.

There is one major drawback of metal hanger of prior art. It typically has a nail-above-hook arrangement, in which, a lateral projectile is provided directly above hook for guiding nail into wall in incline position. When user is holding picture frame above hanger in an attempt to hang the picture frame, he needs to maneuver the metal wire of picture frame to bypass the lateral projectile while sliding picture frame against wall in downward direction. Afterward, he needs to maneuver the metal wire into the hook that is immediately below the lateral projectile. Many users consider such maneuver task troublesome and user-unfriendly.

Using metal hanger in lieu of plastic hanger also has two obvious disadvantages: (1). Metal hanger has higher material and manufacturing costs. (2). Metal hanger is vulnerable to corrosion, particularly, metal-to-metal contact corrosion between the metal body of hanger and the metal wire of picture frame. Unfortunately, plastic hangers of prior art characteristically have limited load capacity due to the inherent low-shear/bending-strength plastic material characteristics.

The motivated concept of present invention is to improve structural design of plastic hanger, and provide a plastic hanger that not only has dual-hooks and hook-above-nail arrangements, but also has a load capacity equivalent to that of metal hangers. The above hanger becomes more user friendly because:

(1). There is no need to adopt a leveling tool (i.e. spirit level). (2). There is no need to mark a horizontal line on wall for installing hangers. (3). Troublesome maneuver task for engaging metal wire of picture frame into hook is eliminated. (4). Adjusting picture frame in a level and balance position takes less effort and time. This is because hanger is provided with a marking along the vertical centerline of hanger, and user can visualize it as a target while aligning the weight center (i.e. center line) of picture frame to the center location between hangers (i.e. dual-hooks). In prior art, when a pair of hangers are installed and separated at a distance on wall, user can't visualize the center location between hangers unless he takes time and effort to take measurement and mark it on wall.

By conducting extensive mechanics analyses and load testing of prototypes, author of present invention is able to achieve the structural design of hanger of present invention that has both dual-hooks and hook-above-nail arrangements, and offers a 50 lb. (or 70 lb.) weight load capacity with two (or three) nails anchoring hanger onto drywall, that is equivalent to the load capacity of a single-hook-dual-nails metal hanger of prior art, or the load capacity of a pair of single-hook-single-nail metal hangers of prior art. Some important design features of hanger of present invention are discussed in detail in later section.

In U.S. Pat. No. 5,178,355, Herzig discloses a hanger with hook-above-nail arrangement. Herzig's hanger has a vertical lower body, an inclined upper body, and an inclined nail hole penetrating upper body along the longitudinal center line of upper body. Top surface of upper body is divided into a rear inclined top surface for hanging a metal wire of picture frame, and a front horizontal top surface for supporting a small L-shaped metal frame of picture frame.

Herzig's hanger has a major drawback that metal wire of picture can easily fall off from top surface of upper body. Herzig's hanger is lack of all the design features of hanger of present invention as discussed in later section. An ordinary designer may modify Herzig's hanger to eliminate the above drawback, but he can't possible modify Herzig's hanger to achieve a load capacity equivalent to that of hanger of present invention. This is due to the fact that, in order to achieve load capacity of hanger of present invention, ratio of “the height of nail exit above bottom edge of lower body” to “the lateral width of open top surface” needs to be equal to or greater than 530%. This design feature of hanger of present invention is based on mechanical analyses and load testing, and can't possibly be comprehended or suggested by an ordinary designer without conducting mechanics analyses and load testing.

We may argue that load capacity of Herzig's hanger can be increased by proportionally enlarging its size without modifying its structural design. In this case (without implementing all the design features of hanger of present invention), the enlarged Herzig's hanger can't possibly achieve a structural strength equivalent to that of hanger of present invention, so that the enlarged Herzig's hanger can't possibly achieve a load capacity equivalent to that of hanger of present invention. Also in this case, overall width of Herzig's hanger will increase proportionally, and thus create a large gap between wall surface and rear surface of picture frame while hanging the picture frame on wall. This is not acceptable because we all know that overall width of hanger needs to be restricted in order to eliminate or minimize such a gap.

In U.S. Pat. No. 7,216,841, Dodig discloses a hanger with dual-hooks arrangement. In first embodiment, hanger has a nail-above-hook arrangement. In second embodiment, hanger has a hook-above-nail arrangement. Dodig's hanger is inherent with low shear/bending strength plastic material characteristics. Without implementing all the design features of hanger of present invention, Dodig's hanger is deemed to be a light-duty hanger for hanging a small picture frame.

SUMMARY OF THE INVENTION

Objective of present invention is to provide a plastic hanger that has both dual-hooks and hook-above-nail arrangements, and offers a load capacity equivalent to that of a pair of single-hook-single-nail metal hangers, or a single-hook-dual-nails metal hanger.

Another objective of present invention is to provide such a plastic hanger with a minimum overall width that minimizes the gap between wall surface and rear surface of picture frame while hanging picture frame onto wall.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective and exploded view of the first preferred embodiment of hanger of present invention.

FIG. 2 is a cross sectional view of FIG. 1.

FIG. 3 is a perspective view of the second preferred embodiment of hanger of present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective and exploded view of the first preferred embodiment of hanger of present invention, in which, hanger 1 comprises of a base plate 2, and a pair of identical left and right lateral projectile 3 and 4 integrally connected to base plate 2.

In FIG. 1, base plate 2 is divided into a left rectangular section 5, a central rectangular section 6, and a right rectangular section 7, in which, left section 5 has a height, width or surface area identical to that of right section 7, but smaller than that of central section 6. Central section 6 is divided into an upper portion 8 above the height of left or right section, and a lower portion 9 below the height of left or right section.

Left lateral projectile 3 or right lateral projectile 4 is integrally connected to left section 5 or right section 7 of base plate 2 to form a hanger body 10 as shown in FIG. 2. In FIG. 2, hanger body 10 comprises of a lower body 11, a transition body 12 projecting upwardly and forwardly from lower body 11, and an upper body 13 projecting upwardly from the front portion of transition body 12.

Lower body 11 has a bottom surface 14, a vertical rear surface 15 emerging from the bottom edge 16 of lower body 11, and a vertical front surface 17. Rear surface 15 is flush to a vertical rear surface 18 of transition body 12. The combined rear surfaces 15 and 18 have a height, width or surface area identical to that of left or right section of base plate 2.

Transition body 12 has an inclined bottom surface 19 sloping upwardly and forwardly from the adjacent front surface 17 of lower body 11, a substantially vertical front surface 20, and an inclined open top surface 21 sloping upwardly and forwardly from rear surface 18. Inclined open top surface 21 is flush to top surface 22 of left or right section of base plate 2.

Transition body 12 has an inclined nail hole 23 that penetrates across the upper portion of transition body 12 from front surface 20 to rear surface 18. Inclined nail hole 23 has an incline angle identical to that of open top surface 21. Inclined nail hole 23 has a nail hole exit 24 located immediately below open top surface 21.

Upper body 13 has a top surface 25, a rear vertical surface 26 emerging from the open top surface 21 of transition body 12, a rear inclined surface 27 projecting upwardly and outwardly from rear vertical surface 26, and a substantially vertical front surface 28 flush to front surface 20 of transition body 12.

Hanger 1 of present invention as described above also has the following important design features:

(1). An indent 29 is provided at the top surface of upper portion 8 of base plate 2 that serves as a visible marking of the vertical centerline of base plate 2. Lower portion 9 of central section 6 of base plate 2 has a slightly greater base plate thickness than that of upper portion 8. Lower portion 9 has an inclined top surface 30 emerging outwardly and downwardly from front surface of upper portion 8. Inclined top surface 30 is at the same height of the top surface 22 of left or right section of base plate 2, and thus serves as a visible marking of the elevation of open top surface 21 where metal wire of picture frame is loaded upon. The above design features allows user to precisely anchor hanger 1 at desired location on wall. Increasing base plate thickness in lower portion 9 of central section 6 of base plate 2 is also necessary in order to increase the structural strength of hanger 1.

(2). Functionally speaking, upper body 13 forms a front leg of an U hook, open top surface 21 of transition body 12 forms an internal side of bottom closed end of U hook, and the upper portion 8 of central section 6 of base plate 2 forms a common rear leg of U hooks.

In order to assure that metal wire of picture frame is securely retained by U hook without possibility of accidentally falling off from U hook or breaking apart the front leg (i.e. upper body 13), upper body 13 has a height equal to twice of the lateral width of open top surface 21, and a lateral width equal to the lateral width of open top surface 21. Lateral width of open top surface 21 is determined by a horizontal distance between the rear vertical surface 26 of upper body 13 and the rear surface 18 of transition body 12.

(3). In order to maximize shear strength of hanger 1, bottom surface 14 of lower body 11 has a lateral wall thickness equal to the lateral width of open top surface 21 of transition body 12, so that shear stress under loading condition can be distributed in the entire vertical cross section of lower body 11.

(4). Functionally speaking, lower body 11 serves as a bending moment resistant cantilever under loading condition. The design feature (3) above assures that lateral thickness throughout lower body 11 is no less than the lateral width of open top surface 21 of transition body 12, and thus maximizes bending strength of hanger 1.

(5). Functionally speaking, transition body 12 serves as a nail anchor body. Transition body 12 adjacent to nail hole exit 24 and below nail hole 23 is subject to maximum bending stress, and thus needs to be reinforced with greater lateral and vertical wall thicknesses. Accordingly, transition body 12 below nail hole 23 envelopes a circular boundary around nail hole exit 24, which has a radius equal to or greater than 160% of the lateral width of open top surface 21.

Due to the consideration that front surface 20 of transition body 12 serves as a nail striking surface, the front portion of transition body 12 has a vertical wall thickness below nail hole 23 that is equal to the lateral width of open top surface 21.

(6). Based on mechanics analyses, maximum load capacity of a wall hanger is determined by the weight load that causes the anchored nail in wall to rotate to a nail pullout angle, and thus causes nail to be pulled out of wall. Before weight load approaches maximum load capacity (as defined above), load capacity of a hook-above-nail hanger is proportional to the vertical distance between the nail exit point and the bottom edge of hanger.

Accordingly, in order to maximize load capacity of hanger 1 of present invention, nail hole exit 24 is at a predetermined height above the bottom edge 16 of lower body 11, and ratio of “the predetermined height of nail hole exit 24” to “the lateral width of open top surface 21 of transition body 11” is about 530%. As confirmed by load testing, at the above ratio, hanger 1 of present invention achieves a 50 lb. weight load capacity when it is anchored to a drywall with two 3d penny size finish nails.

(7). Based on mechanics analyses, the incline angle of anchored nail in wall does not affect nail pullout angle, nor does it affect load capacity of hanger. Furthermore, in order to maximize load capacity of a hook-above-nail hanger, the vertical distance between the load landing point (i.e. the internal bottom closed end of U hook) and the nail exit point needs to be minimized. By specifying the incline angle of open top surface 21 identical to that of nail hole 23, such a vertical distance is therefore minimized. Based on the geometry of hanger 1 of present invention, the vertical and lateral wall thickness surrounding nail hole exit 24 can be maximized by decreasing incline angle of nail hole 23. When two hangers have an identical size, the hanger with smaller incline angle has a greater nail exit height above the bottom edge of hanger, and thus has a greater load capacity. But inclined angle of nail hole 23 needs to be at least some degrees above a horizontal plane to prevent nail from being accidentally pulled out of wall by external force. Accordingly, inclined angle of nail hole 23 is determined at 15 degree that is significantly less than typical 30 to 45 degree incline angle of conventional metal hanger.

(8). Hanger body 10 (FIG. 2) has an overall width determined by the greatest lateral wall thickness in transition body 12, and ratio of “the lateral width of open top surface 21 of transition body 12” to “the overall width of hanger body 10” is about 50%. This is due to the consideration that overall width of hanger body 10 needs to be sufficiently small to minimize the gap between wall and the top rear surface of picture frame while hanging the picture frame, but the lateral width of top opening of U hook or the lateral width of open top surface 21 needs to be sufficiently large to allow metal wire of picture frame to be easily caught by U hook while engaging metal wire of picture frame into U hook.

It is understood that some modifications to hanger 1 can be done to enhance the appearance of hanger 1 without affecting its shear/bending strength or load capacity. For example, front surface 17 of lower body 11, inclined bottom surface 19 and front surface 20 of transition body 12, and front surface 28 of upper body 13 can be integrated into a continuously curved front surface. For another example, bottom surface 14 can be an inclined surface rather than a horizontal surface. These modifications are considered within the scope of present invention.

FIG. 3 is a perspective view of the second preferred embodiment of hanger of present invention, in which, hanger 31 comprises of a base plate 32 resemble to base plate 2 of first preferred embodiment, a pair of identical left and right lateral projectiles 33 and 34 resemble to left and right lateral projectiles 3 and 4 of first preferred embodiment, and a third central lateral projectile 35.

As similar to base plate 2 of first preferred embodiment, central section 36 of base plate 32 is divided into an upper portion 37 and a lower portion 38. Third lateral projectile 35 is integrally connected to the lower portion 38 along the centerline of base plate 32. Third lateral projectile 35 has an inclined nail hole 39 that penetrates across third lateral projectile 35 from inclined top surface 40 to rear surface (not shown), and continuously penetrates across base plate 32.

Hanger 31 of second preferred embodiment offers two advantages over hanger 1 of first preferred embodiment. First, as confirmed by load testing, hanger 31 offers a greater load capacity at 70 lb. as hanger 31 being anchored to drywall with three 3d penny size finish nails. Second, user can install hanger 31 onto wall at desired location by anchoring the first nail through nail hole 39 of third central lateral projectile 35, so that he can adjust hanger 31 to a level position and subsequently anchor the second and third nails without holding hanger 31 by hand. Hanger 1 requires user to hold hanger 1 by hand at all time while installing hanger 1 onto wall.

Claims

1). A wall hanger for hanging a metal wire of a picture frame or the like, which comprises of a base plate, and a pair of identical first and second lateral projectiles integrally connected to said base plate, wherein: said base plate is divided into a left, central and right rectangular sections, in which, said left section has a height, width or surface area identical to that of said right section, but smaller than that of said central section, and said central section is divided into an upper and lower portions above and below said height of said left or right section respectively,said first and second lateral projectiles are integrally connected to front surfaces of said left and right sections of said base plate respectively,said first or second lateral projectile is integrally connected to said left or right section of said base plate to form a hanger body that comprises of a lower body, a transition body projecting upwardly and forwardly from said lower body, and an upper body projecting upwardly from the front portion of said transition body,said lower body has a bottom edge, a vertical rear surface emerging from said bottom edge, a bottom surface, and a substantially vertical front surface emerging from said bottom surface,said transition body has a vertical rear surface flush to said vertical rear surface of said lower body, an inclined open top surface sloping upwardly and forwardly from said rear surface, an inclined bottom surface sloping upwardly and forwardly from said front surface of said lower body, a substantially vertical front surface emerging from said bottom surface, and an inclined nail hole penetrating across an upper portion of said transition body from said front surface to said rear surface, in which, said inclined nail hole has a about 15 degree incline angle identical to that of said open top surface of said transition body, and said inclined nail hole has a nail hole exit located immediately below said open top surface of said transition body,said upper body has a top surface, a lower vertical rear surface emerging from said open top surface of said transition body, an upper inclined rear surface sloping upwardly and forwardly from said lower vertical rear surface, and a substantially vertical front surface flush to said front surface of said transition body,said upper body forms a front leg of an U hook, said open top surface of said transition body forms an internal side of bottom closed end of said U hook, and said upper portion of said central section of said base plate forms a common rear leg of said U hooks,said open top surface of said transition body has a lateral width determined by a horizontal distance between said rear surfaces of said upper and transition bodies, said hanger body has an overall width determined by the greatest lateral thickness in said transition body, and ratio of “said lateral width of said open top surface of said transition body” to “said overall width of said hanger body” is about 50%,said upper body has a height equal to or greater than 200% of said lateral width of said open top surface of said transition body, and a lateral width at the juncture of said upper and transition bodies is about equal to said lateral width of said open top surface of said transition body,said bottom surface of said lower body has the smallest lateral thickness in said lower body, that is equal to or greater than said lateral width of said open top surface of said transition body,said transition body below said nail hole envelopes a circular boundary around said nail hole exit, and said circular boundary has a radius equal to or greater than 160% of said lateral width of said open top surface of said transition body,said front portion of said transition body has a vertical wall thickness below nail hole that is equal to or greater than said lateral width of said open top surface of said transition body,said nail hole exit is at a predetermined height above said bottom edge of said lower body, and ratio of “said predetermined height of said nail hole exit” to “said lateral width of said open top surface of said transition body” is equal to or greater than 530%,said base plate has an indent located at a top surface of said upper portion of said base plate that serves as a visible marking of the vertical centerline of said base plate, said lower portion of said base plate has a plate thickness slightly greater than that of said upper portion of said base plate, and said lower portion of said base plate has an inclined top surface emerging outwardly and downwardly from the front surface of said upper portion of said base plate, which serves as a visible marking of the elevation of said open top surface of said transition body where said metal wire of said picture frame is loaded upon.

2). The wall hanger according to claim 1, in which, a third lateral projectile is integrally connected to said lower portion of said central section of said base plate along said vertical centerline of said base plate, said third lateral projectile has an inclined nail hole with an incline angle identical to that of said first or second lateral projectile, and said inclined nail hole penetrates across said third lateral projectile and continuously penetrates across said base plate.

3). The wall hanger according to claim 1, in which, said bottom surface of said lower body is a horizontal bottom surface.

4). The wall hanger according to claim 1, in which, said bottom surface of said lower body is an inclined bottom surface sloping upwardly and forwardly from said bottom edge of said lower body.

5). The wall hanger according to claim 2, in which, said third lateral projectile has a horizontal bottom surface.

6). The wall hanger according to claim 2, in which, said third lateral projectile has an inclined bottom surface sloping upwardly and forwardly from the bottom edge of said third lateral projectile.