S-beam garment hanger
This injection molded plastic garment hanger has a body part formed as a horizontal beam having a generally S-shape cross section, a hook at the top and optional spring clamps, hooks and projections on the beam for engaging, holding and supporting garments.
This invention is in the field of injection molded plastic garment hangers for transporting and displaying garments on racks, and particularly garment hangers of the type where the body part of the hanger below the rack-engaging hook is a generally straight horizontal bar having a plurality of spring clamps, hooks and/or projections for engaging, holding and supporting garments.
BACKGROUND OF THE INVENTIONCommon molded plastic garment hangers of the type whose body parts are thin straight beams, often bend and sometimes twist and buckle when loaded. Since these hangers are made, used and discarded by the millions, economy of manufacture is important, and accordingly, these hangers are frequently designed to have a thin I-beam cross-section which requires a relatively small amount of plastic for a moderately strong hanger.
The problems of twisting and buckling are common because of the nature of loading of the hangers, where garment straps or other garment elements are attached at the ends of the beam, thus producing cantilever loads and bending, twisting and buckling stresses. I-beam design, while common, is limited in its usefulness because the size dimensions of garment hangers are restricted, and the amount of plastic that can be economically used is also restricted. One example of a prior art molded garment hanger with an I-beam structure is U.S. Pat. No. 5,129,557 which is incorporated herein by reference.
I-beams, whether used for building, machinery or garment hanger construction, follow well recognized and well studied scientific rules of bending, shear and twisting stress loading and deflection. When using I-beams for building and machinery construction, a design engineer typically calculates the required thicknesses and breadths of the I-beam's webs and flanges, with size, weight and cost being secondary to strength and safety requirements. In the field of garment hanger construction, attempts have been made to utilize this knowledge of I-beam construction; however, it is not feasible to simply make the hangers larger, thicker or increase flanges of an I-beam body shape, primarily because of the increased cost of material and manufacture in this very high volume industry and also because added weight or size is undesirable.
The present invention involves the development of a different and non-traditional beam structure, which provides the desired strength and resistance to twisting and buckling, with the quantity of plastic required per hanger and the cycle time for manufacture essentially the same or less than what is required for prior art I-beam hangers.
SUMMARY AND OBJECTS OF THE NEW INVENTIONOne object of this invention is to provide a new molded garment hanger which has greater strength and resistance to buckling when loaded with a garment than prior hangers which were considered unreliable. Buckling in this application means excessive bending primarily in the forward and downward directions, which may be forward twisting. It is an object to provide hangers that resist such buckling and thus support and present the garments in a more desirable manner.
It is a further object to provide buckling resistant molded garment hangers which have generally the same outer dimensions as prior art hangers, and preferably have similar cross-sectional area which means they would contain essentially the same amount of plastic.
It is a still further object in certain embodiments of the invention that the new hangers have cross-sections that are generally uniform.
It is an additional object that the new hangers have greater resistance to buckling than prior art hangers having I-beam or M-beam construction.
Another object is to provide molded hangers that are economical in regard to cost of material and cost of manufacture.
In summary, it is an object to provide molded hangers that are better in resistance to buckling and in other regards than prior art hangers.
Hangers of the new invention may have a variety of known body part shapes including but not limited to a straight horizontal beam shape, rounded shoulders shape, and a low profile shape with opposite shoulders elevated above the central section. In a first embodiment the new invention is an injection molded plastic garment hanger having a straight horizontal beam body part with an S-shape cross-section. Load and displacement plots from test results reveal that a beam having this new S-shape cross-section has greater strength and resistance to buckling than do beams of generally equal cross-sectional area in prior art I-beam or prior art M-beam configurations.
In this first preferred embodiment the S-shape cross-section has upper and lower curves which together form a continuous central web. Each of said upper and lower curves has a free end formed as a generally horizontally extending foot with an oppositely extending heel. The foot and heel at the top and bottom of the new S-shape correspond generally to the top and bottom flanges of a prior art I-beam. The web and the flanges of the new S-shape have generally uniform thickness.
Within this S-beam cross-section is a central longitudinal axis which divides the cross-section, such that there is essentially equal lateral extension or equal area on each side of the central vertical axis. Corresponding to this central vertical axis of the S-shape is a central vertical plane extending lengthwise of the S-beam. With respect to this central vertical plane, the toe of the lower flange foot, the upper curve of the web and the heel of the upper flange all extend the same distance forward, thus establishing a front plane of the beam. The toe of the upper flange foot, the lower curve of the web and the heel of the lower flange all extend the same distance rearward of the central vertical plane, thus, establishing a rear plane of the beam.
A garment hanger using the new S-beam has a typical rack-engaging hook extending from the top of the beam. This preferred embodiment also has spring clamps at the opposite ends of the beam respectively for engaging garments, and has spaced apart fingers extending downwardly from the bottom edge of the beam for engaging the garment.
The first preferred embodiment may be summarized as an injection molded plastic garment hanger comprising:
a. a hook having a top part, a stem extending downward from said top part and a bottom part, and
b. a body part formed as a generally horizontally extending beam having a central part and arms extending oppositely from said central part and terminating in opposite ends,
said bottom part of said hook being joined to said central part of said beam,
said beam's central part and arms comprising a web having upper and lower portions and extending lengthwise of said beam and extending downward from said hook,
said web in cross-section defining a generally S-shape comprising upper and lower portions thereof, and
said web's upper portion having a top part which extends forwardly as a top front flange of said beam terminating in a font edge, and said web's lower portion having a bottom part which extends rearwardly as a bottom rear flange of said beam terminating in a rear edge.
In a further embodiment of the new hanger, said continuous upper and lower curves of the S-shaped cross-section define a web with top and bottom flanges which extend generally horizontally in opposite directions respectively, each of said flanges comprising a foot having a toe portion that extends forwardly and a heel portion that extends rearwardly.
In a still further embodiment of the new hanger said S-shape has a generally central vertical axis corresponding to a central vertical plane of said S-beam, wherein said top and bottom flanges extend forwardly and rearwardly substantially the same distances respectively from said central vertical plane.
In a second preferred embodiment of the new garment hanger, the straight horizontal beam body part has a modified Z-shape cross-section formed as an upper Z directly above a lower Z, where the bottom horizontal foot of the upper Z serves as the top horizontal foot of the lower Z. These top and bottom feet correspond to transverse flanges in an I-beam. The material between the top and bottom horizontal feet is a zig-zag web which has generally uniform thickness. The top and bottom feet have thickness similar to that of the web thickness. In this double Z combination beam the upper and lower Zs share a common central vertical axis, which is not an axis of symmetry because of the nature of the double Z shape.
The Z-beam hanger, in summary, comprises:
a. a hook having a top part, a stem extending downwardly from said top part and a bottom part, and
b. a body part formed as a beam extending transversely of said hook, said beam having a central part and arms extending oppositely from said central part and terminating in opposite ends,
said bottom part of said hook being joined to said central part of said beam,
said beam's central part and arms comprising a web having upper and lower portions extending lengthwise of said beam and extending downward from said hook,
said web in cross-section defining a generally Z-shape comprising a stem, with upper and lower portions of said web forming respectively a top front flange extending forwardly and terminating in a front edge, and a bottom rear flange extending rearwardly and terminating in a rear edge.
In a still further embodiment of the Z-shape hanger the web in cross-section comprises a set of upper and lower Z-shapes, where each Z-shape has upper and lower generally horizontal feet, and where the lower foot of the upper Z-shape comprises the upper foot of the lower Z-shape, this common foot being an intermediate flange between said top front and bottom rear flanges.
In a further embodiment said upper and lower feet define upper and lower flanges respectively of said Z-beam, and said shared foot defines a middle flange.
As indicated above, the S-beam and Z-beam cross-sections may be incorporated into various body part shapes including a hanger having traditional rounded shoulder hanger and a hanger having low profile shoulders that rise above a central part.
The low profile hanger, in summary, comprises:
a. a hook having a top and bottom parts, and
b. a body part formed as a transversely extending beam having a central part and shoulder parts extending outward from said central part and terminating in opposite ends,
said bottom part of said hook being joined to said central part of said beam,
said shoulder parts being at an elevation above said central part, wherein said central part and said shoulder parts define a generally low profile shape, said beam's central part and shoulder parts comprising a web extending lengthwise of said beam and extending downward from said hook,
said web in cross-section defining a generally S-shape comprising upper and lower portions thereof,
said web's upper portion having a top part which extends forwardly as a top front flange of said beam terminating in a front edge, and said web's lower portion having a bottom part which extends rearwardly as a bottom rear flange of said beam terminating in a rear edge.
On comparing stress/displacement plots for the new S-beam and the prior art I-beam, the results for straight horizontal test beams demonstrate that the S-beam shows less twisting and buckling deflection from the same vertical loading. Details of the loading and deflection plots are presented below, which demonstrate impressively how the S-beam is substantially stronger than the I-beam against buckling loads, despite the fact that both beams have essentially the same cross-sectional areas, consume essentially the same quantity of plastic, and have about the same height.
Further features and advantages of the invention as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
A. The S-beam Garment Hanger
The new S-beam garment hanger 10, as seen in
Beam 12 of hanger 10, shown in cross-section in
The bottom of web 22 is formed as a horizontally extending foot 23 having a toe portion 24 and an oppositely extending heel portion 25. At the top of web 22 is a similar but opposite foot 26 having a toe portion 27 and an oppositely extending heel portion 28. A central vertical axis Y1-Y1 divides this cross-section into essentially equal but non-symmetrical halves. Corresponding to this central vertical axis is a central vertical plane extending lengthwise through the S-beam.
In the cross-section as seen in
B. The Z-beam Garment Hanger
The second embodiment of the garment hanger of the present invention is called the Z-beam hanger, which is very similar to the above-described S-beam hanger, except for the fact that its horizontal beam defines in cross-section a set of upper and lower Z elements, 32 and 33 respectively, as seen in
In the cross-section as seen in
The load or stress on these hangers will vary depending on where and how a garment is attached and how the garment's weight is distributed. The above-described I-beam, S-beam and Z-beam elements have been tested under loading conditions simulating actual garment hanger loading, with the results shown in
C. An S-beam Rounded Shoulder Hanger
D. An S-beam Low Profile Hanger
E. A Second S-beam Low Profile Hanger
Following below are descriptions of load/displacement/stress plots for a prior art I-beam as a point of reference, and for the new S-beam and the new Z-beam. Each of these plots utilizes an X, Y, Z coordinate system where Y represents the vertical load direction and vertical displacement axis, Z represents the lateral load direction and lateral displacement axis, and X represents the beam's longitudinal axis.
F. I-beam: Load/Displacement/Stress Plots
In
G. S-beam: Load/Displacement/Stress Plots
H. Z-beam: Load/Displacement/Stress Plots
Table 1 shown below displays a comparison of the above-described displacement plots for the I-beam, S-beam and Z-beam, where all of these beams have the same length, load and cross-sectional area, but have different cross-sectional configurations. As seen in Table 1, when subject to the one pound vertical loading:
a. Y-Displacement: the I-beam had the least vertical (y) displacement (0.257 in.), the S-beam was next (0.303 in.), and the Z-beam had the greatest displacement (0.308 in.)
b. Z-Displacement: the I-beam had the least lateral (z) displacement (0.000 in.), the Z-beam was next (0.046 in.), and the S-beam had the greatest (0.202 in.), and
c. Buckling Load: the S-beam supported the greatest buckling load 2.901 lbs., the I-beam was next with 2.396 lbs, and the Z-beam supported the least with 2.016 lbs.
Table 2, as expected, shows the S-beam (which supported the greatest buckling load) had the lowest von Mises stress of 1,426 psi compared to 1,872 psi for the I-beam and 1,755 psi for the Z-beam.
In all these beams the plastic was Acrco HM20Z1 Polypropylene having a modulus of 220,000 psi.
These results demonstrate that as compared to I-beams and Z-beams, the S-beam has significantly greater buckling strength. As noted above, all three beams had approximately the same cross-sectional area and thus used approximately the same amount of plastic.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
Claims
1. An injection molded plastic garment hanger, comprising:
- a. a hook having a top part, a stem extending downward from said top part and a bottom part, and
- b. a body part formed as a generally horizontally extending beam having a central part and arms extending oppositely from said central part and terminating in opposite ends,
- said bottom part of said hook being joined to said central part of said beam,
- said beam's central part and arms comprising a web having upper and lower portions and extending lengthwise of said beam and extending downward from said hook,
- said web in cross-section defining a generally S-shape comprising upper and lower portions thereof,
- said web's upper portion having a top part which extends forwardly as a top front flange of said beam terminating in a font edge, and said web's lower portion having a bottom part which extends rearwardly as a bottom rear flange of said beam terminating in a rear edge.
2. A garment hanger according to claim 1 wherein said upper and lower portions of said S-shape define a set of continuous reverse curves.
3. A garment hanger according to claim 1 wherein said web further comprises a top rear flange extending rearwardly from said top portion of said web along the length thereof, and a bottom front flange extending frontwardly from said bottom portion of said web along the length thereof.
4. A garment hanger according to claim 3 wherein said top rear flange and said top front flange extend generally oppositely from each other, and said bottom front flange and said bottom rear flange extend generally oppositely from each other.
5. A garment hanger according to claim 3 wherein said web's upper portion forms a top foot with said top front and top rear flanges being top toe and heel elements of said top foot, and said lower portion forms a bottom foot with said bottom front and rear flanges being bottom toe and heel elements of said bottom foot.
6. A garment hanger according to claim 5 wherein said top toe and heel elements extend generally in a top plane and said bottom heel and toe elements extend generally in a bottom plane generally parallel to said top plane.
7. A garment hanger according to claim 3 wherein said top front and top rear flanges extend generally horizontally in a common top plane, and said bottom front and bottom rear flanges extend generally horizontally in a common bottom plane.
8. A garment hanger according to claim 1 wherein said web has a generally uniform thickness.
9. A garment hanger according to claim 4 wherein said web defines a central vertical plane extending lengthwise therethrough, and said front top and bottom flanges and said rear top and bottom flanges have front edges and rear edges respectively which extend forward and rearward respectively of said central vertical plane by generally equal distances.
10. A garment hanger according to claim 9 wherein said upper and lower curves of said S-shape extend forward and rearward of said central vertical plane generally by the same distance as said front and rear flanges extend.
11. A hanger according to claim 9 wherein said S-shape in cross section defines an area forward of said central vertical plane of said web that is substantially the same as the cross-sectional area rearward of said central vertical plane.
12. A hanger according to claim 1 wherein said garment hanger is a one piece injection molded product.
13. A hanger according to claim 1 wherein said S shape cross section has height to breadth ratio of about 2:1.
14. An injection molded plastic garment hanger, comprising:
- a. a hook having a top part, a stem extending downwardly from said top part and a bottom part, and
- b. a body part formed as a beam extending transversely of said hook,
- said beam having a central part and arms extending oppositely from said central part and terminating in opposite ends,
- said bottom part of said hook being joined to said central part of said beam,
- said beam's central part and arms comprising a web having upper and lower portions extending lengthwise of said beam and extending downward from said hook,
- said web in cross-section defining a generally Z-shape comprising a stem, with upper and lower portions of said web forming respectively a top front flange extending forwardly and terminating in a front edge, and a bottom rear flange extending rearwardly and terminating in a rear edge.
15. A garment hanger according to claim 14 wherein said web in cross-section comprises a set of upper and lower Z-shapes, where each Z-shape has upper and lower generally horizontal feet, and where the lower foot of the upper Z-shape comprises the upper foot of the lower Z-shape, this common foot being an intermediate flange between said top front and bottom rear flanges.
16. A garment hanger according to claim 15 wherein said top front flange, bottom rear flange and intermediate flange have substantially the same thickness and depth.
17. A hanger according to claim 14 wherein said garment hanger is a one piece injection molded product.
18. A hanger according to claim 14 wherein said upper and lower Z shapes have essentially the same size and shape.
19. A hanger according to claim 14 wherein said web's cross section has height to breadth ratio of about 2:1.
20. A hanger according to claim 14 wherein said web's cross section has height to breadth ratio in the range of about 1.7 to 2.4.
21. An injection molded plastic garment hanger comprising:
- a. a hook having a top and bottom parts, and
- b. a body part formed as a transversely extending beam having a central part and shoulder parts extending outward from said central part and terminating in opposite ends,
- said bottom part of said hook being joined to said central part of said beam,
- said shoulder parts situated at an elevation different from said central part,
- said beam's central part and shoulder parts comprising a web extending lengthwise of said beam and extending downward from said hook,
- said web in cross-section defining a generally S-shape comprising upper and lower portions thereof,
- said web's upper portion having a top part which extends forwardly as a top front flange of said beam terminating in a front edge, and said web's lower portion having a bottom part which extends rearwardly as a bottom rear flange of said beam terminating in a rear edge.
22. A hanger according to claim 21 wherein said shoulder parts curve outward and downward from said central part.
23. A hanger according to claim 21 wherein shoulder parts are at an elevation above said central part.
Type: Application
Filed: Jun 24, 2004
Publication Date: Dec 29, 2005
Inventor: Patrick Fleming (Cuyahoga Falls, OH)
Application Number: 10/875,818