# Patent

## Title
Base plate for magnetic attachment assembly

## Abstract

Described is a removable assembly for use on a fixed surface. The assembly includes a post having a base (42) and an attachment assembly (8). The attachment assembly includes a base plate (10) and a magnet assembly (12), both capable of carrying a magnetic current. The magnet assembly includes a housing (20) and a magnet (22) disposed within the housing. To use, the magnet assembly is placed adjacent the base plate, the magnetic forces attracting and holding them together. The magnet is positioned apart from the base plate while the housing contacts the base plate to form the magnet circuit. An attachment plate (30) is connected to the housing upper wall adjacent its outer surface. The attachment plate includes one or more outwardly projecting attachment bolts (26). As assembled, the bolts engage corresponding openings (48) in the post base (42).

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of application Ser. No. 10/270,790, filed Oct. 11, 2002 now U.S. Pat. No. 6,739,567.


FIELD OF THE INVENTION
The present invention relates to supports, and more particularly, to a frangible magnetic assembly for use in attaching a post, stanchion, pole, standard, divider, delineator, or the like, to a fixed base.
BACKGROUND OF THE INVENTION
Cities often have a need for a temporary sign that can be used to alert drivers as to when it is unacceptable to park their vehicles at a particular location, e.g., due to a parade, construction work, vehicle loading/unloading, etc. In the past, traditional parking meters were available on which workers could place “No Parking” hoods or covers. These meters are being eliminated in many cities in favor of single, centrally located parking pay stations.
Thus, a need exists for a temporary structure to support a sign or other indicator at a particular height and location. To meet this need, a preferred arrangement would be capable of attaching a post, stanchion, pole, standard, or the like, to a fixed base. Ideally, the structure would be easy to install and remove by authorized personnel, but difficult to disturb by unauthorized persons. In addition, it would be advantageous for some applications, if the device could preferably withstand the impact of being inadvertently hit by a vehicle. The present invention is directed to fulfilling these needs and others as described below.
SUMMARY OF THE INVENTION
In accordance with aspects of the present invention, a removable assembly for use on a fixed surface is described. The assembly includes a post with a base and an attachment assembly. In one embodiment, the post is a self-righting impact-recovery post. An optional shroud is available for placement between the attachment plate and the base of the post.
The attachment assembly includes a base plate capable of carrying a magnetic current and capable of engaging the fixed surface. The a magnet assembly includes a housing and a magnet disposed within the housing. The housing is formed of a magnetizable material and includes an upper wall with an outer surface. As formed, magnetic current from the magnet causes an attractive force between the housing and the base plate, the magnet itself being positioned apart from the base plate while the housing contacts the base plate. An attachment plate is attached to the housing upper wall, adjacent its outer surface. The attachment plate includes one or more outwardly projecting attachment bolts. These bolts engage the base of the post, as assembled.
In accordance with other aspects of this invention, in another embodiment, the magnet is a ring magnet and the housing has a circular cup shape. Alternatively, an arrangement is described in which the magnet is a bar magnet and the housing has a rectangular channel shape. As assembled, the bar magnet is located colinearly in the housing. Further configurations may be formed in which multiple bar magnets and channel housings are used, each having a unique orientation.
In accordance with further aspects of this invention, the base plate includes an opening and the attachment plate includes a bolt extending downward from the attachment plate, through the magnet assembly, and engaging the opening of the base plate. During use, this engagement helps to maintain the attachment plate and magnet assembly on the base plate.



BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a separable magnetic attachment assembly formed in accordance with the present invention;
FIG. 2A is an exploded detail view with a partial cutaway section of one embodiment of an assembly formed in accordance with the present invention;
FIG. 2B is an exploded detail view of another embodiment of an assembly formed in accordance with the present invention;
FIG. 3 is a cross-sectional side view of the embodiment of FIG. 2A; and
FIG. 4 is a perspective view further illustrating the embodiment of FIG. 2B.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the present invention is an attachment assembly 8 particularly useful for securing a post, stanchion, pole, standard, or the like, to a fixed base. As used herein, the term “post” is used generally to mean any type of temporary object, and particularly elongated objects. Examples include posts that hold signs, posts used in sports applications, and posts used in creating temporary fences or barriers. Numerous other applications are possible. As delineated by the claims, the assembly may also be used with other objects (elongated or otherwise) for which it is desirable to have a quick and easy means of separably attaching the object to a base.
Referring to FIGS. 2A and 2B, the assembly includes a base plate 10 and a magnet assembly 12. A post or other object is connectable to the magnet assembly, preferably in a manner that one is separable from the other. In these embodiments, the base plate is a circular steel disc having a beveled outer periphery. It is approximately 5 inches in diameter and 3/16-inch in thickness. The base plate is permanently adhered to (or formed into) a sidewalk or other hard smooth surface. The upper surface 16 of the base plate 10 is preferably made of a nonskid material. This is particularly useful if there is a need to meet safety standards for public use. The base plate 10 includes an opening 18 at its center. In one embodiment, the opening is a 1⁄2-inch by 1⁄2-inch square.
In the arrangements of FIGS. 2A and 3, the magnet assembly 12 includes a cup-shaped metal housing 20 and a ring magnet 22. The ring magnet 22 is adhered onto the upper inside surface of the housing. The lower portion of the housing is open. In this way, the housing has a shallow upside-down bowl shape. The upper surface of the housing includes a number of upwardly extending attachment bolts 26. A central bolt 28 extends downwardly from the middle of the housing. In the embodiment shown, the attachment bolts 26 and the central bolt 28 are formed on opposite sides of an attachment plate 30. An opening in the center of the housing allows the central bolt to extend downward therethrough. As will be appreciated from those skilled in the art, other configurations are possible.
In FIG. 2B, the magnet assembly 12 includes separate U-shaped housings 20′ that each contain their own magnet 22′. The housings 20′ face downward, end-to-end, in a circular arrangement. An attachment plate 30 is connected to the upper surfaces of the housings. One of the advantages of the arrangement of FIG. 2B is that it provides a magnetic arrangement that is difficult to accidentally remove from the base plate. Because the magnets are provided in opposing orientations, shearing forces are minimized. This further allows the use of particularly strong magnets, such as rare-earth magnets (e.g., neodymium magnets).
In either arrangement, the housing is preferably made of a material that can carry a magnetic current, e.g., steel. This allows the housing to attract and attach to the base plate during use, as opposed to the magnet or magnets attaching directly to the base plate. In general, such arrangement is referred to as a “cup magnet” arrangement, since it is the “cup” itself that is physically connected to a magnetic surface.
In some embodiments, the strength of the magnets will be significant. If such magnets are attached directly to the base plate, the task of manually separating these parts may become too difficult for the average user. In FIG. 2A, the notch 34 is available in the assembly housing to allow a user to pry the magnet assembly from the base plate. The ring magnet is preferably formed of a rare-earth or ceramic material.
As mentioned above, the attachment assembly of the present invention is particularly useful for separably connecting a post 14 to a fixed base. In FIG. 1, a sign 40 is shown releasably connected to a sidewalk. In this arrangement, the preferred post is a conventional impact-recovery post. The impact-recovery post includes a spring-loaded base 42 and an upright pole 44. The base 42 includes a number of boltholes 48 positioned to align with the magnet assembly's attachment bolts.
To assemble the sign of FIG. 1, the base 42 is bolted onto the attachment bolts 26, with an optional rubber shroud 50 positioned therebetween. The combination is then lowered onto the base plate 10 that is adhered to the sidewalk, or other essentially smooth solid surface. In this embodiment, the magnet 22 does not directly touch the base plate 10. Magnetic forces between the lower edges of the housing 20 and the base plate 10 are sufficient to maintain the magnet assembly on the base plate. An opening 53 in the shroud is available for use in peeling the magnet assembly from the base plate. See FIG. 2A. A lever-type prying device is inserted into the opening 54 and rotatable about a fulcrum contacting the adjacent ground. The user pries the magnet assembly away from the base plate.
While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.

## Claims

1. In a separable magnetic assembly for reversibly securing an object to a ground attachment surface, the assembly including a housing, at least one magnet disposed within the housing, a fastening assembly adapted to couple an object to the housing, and a base plate for being coupled to the ground attachment surface and reversibly receiving the at least one magnet disposed in the housing, the base plate comprising:
(a) a circular body capable of carrying a magnetic current, the circular body having a beveled outer perimeter sidewall, a substantially planar upper surface, and a substantially planar base surface opposing the substantially planar upper surface, wherein the beveled outer perimeter sidewall is a linear bevel tapering outwardly between an outer edge of the substantially planar upper surface and an outer edge of the substantially planar base surface;
(b) a centrally-located opening extending through the circular body from the substantially planar upper surface to the substantially planar base surface, the centrally-located opening sized and configured for receiving a bolt downwardly extending from the magnetic assembly, wherein the substantially planar upper surface extends between the beveled outer perimeter sidewall and the centrally-located opening, and wherein the shortest distance on the substantially planar upper surface from the beveled outer perimeter sidewall to the centrally-located opening is equal to or greater than the greatest distance across the centrally-located opening; and
(c) the substantially planar upper surface having a non-skid surface.

2. The base plate according to claim 1, wherein the base plate is made of a material including at least steel.

3. The base plate according to claim 1, wherein the base plate is a flat disc.

4. The base plate according to claim 1, wherein the centrally-located opening is a square opening.

5. A base plate for reversibly receiving a magnetic assembly, the magnetic assembly including at least one magnet disposed in the housing, the base plate comprising:
(a) a body capable of carrying a magnetic current having a substantially planar upper surface and a substantially planar base surface opposing the substantially planar upper surface, wherein the substantially planar upper surface is substantially free of protrusions extending upward from the substantially planar upper surface;
(b) a beveled outer perimeter sidewall, wherein the beveled outer perimeter sidewall is a linear bevel tapering outwardly from an outer edge of the substantially planar upper surface to an outer edge of the substantially planar base surface;
(c) a centrally-located square-shaped opening extending through the body from the substantially planar upper surface to the substantially planar base surface, the centrally-located opening sized and configured for receiving a bolt downwardly extending from the magnetic assembly to extend therein, wherein the substantially planar upper surface extends between the beveled outer perimeter sidewall and the centrally-located opening, and wherein the shortest distance on the substantially planar, upper surface from the beveled outer perimeter sidewall to the centrally-located opening, is equal to or greater than the greatest distance across the centrally-located opening; and
(d) a non-skid material disposed on the substantially planar upper surface.

6. The base plate according to claim 5, wherein the base plate is made of a material including at least steel.

7. The base plate according to claim 5, wherein the base plate is a flat disc.

8. The base plate according to claim 1, wherein the circular body is a flat disc having a substantially planar base surface disposed below the substantially planar upper surface by less than about a 1⁄2 inch.

9. The base plate according to claim 5, wherein the body is a flat disc having a substantially planar base surface disposed below the substantially planar upper surface by less than about a 1⁄2 inch.

10. In a separable magnetic assembly for reversibly securing an object to a ground attachment surface, the assembly including a housing, at least one magnet disposed within the housing, a fastening assembly adapted to couple an object to the housing, and a base plate for being coupled to the ground attachment surface and magnetically coupled to the at least one magnet disposed in the housing, the base plate comprising:
(a) a circular body capable of carrying a magnetic current and having a substantially planar upper surface and a substantially planar base surface opposing the substantially planar upper surface;
(b) a beveled outer perimeter sidewall, wherein the beveled outer perimeter sidewall is a linear bevel tapering outwardly from an outer edge of the substantially planar upper surface to an outer edge of the substantially planar base surface, the substantially planar base surface disposed substantially parallel with the substantially planar upper surface and spaced from the substantially planar upper surface by less than a 1⁄2 inch, and wherein the outer perimeter sidewall bevel angle is configured so as not to present a tripping hazard when the substantially planar base surface is coupled to the ground attachment surface;
(c) a centrally-located opening, wherein the centrally located opening is non-circular in shape and extends entirely through the circular body from the substantially planar upper surface to the substantially planar base surface, the centrally-located opening configured for permitting a portion of the magnetic assembly to extend therein, and wherein the substantially planar upper surface extends between the beveled outer perimeter sidewall and the centrally-located opening; and
(d) a non-skid material disposed on the substantially planar upper surface.

11. The base plate according to claim 10, wherein the circular body is free of any fastening structures.

12. The base plate according to claim 10, wherein the circular body has a diameter of approximately 5 inches.

13. The base plate according to claim 10, wherein the circular body is free of any holes passing through the circular body other than the centrally-located opening.

14. The base plate according to claim 1, wherein the beveled outer perimeter sidewall is configured so as not to present a tripping hazard when attached to a walking surface.

15. In a separable magnetic assembly for reversibly securing an object to a ground attachment surface, the assembly including a housing, at least one magnet disposed within the housing, a fastening assembly adapted to couple an object to the housing, and a base plate configured for coupling to the ground attachment surface and reversibly magnetically receiving the at least one magnet disposed in the housing, the base plate comprising:
(a) a circular body capable of carrying a magnetic current, the circular body having a beveled outer perimeter sidewall, a substantially planar upper surface, and a substantially planar base surface opposing the substantially planar upper surface, wherein the beveled outer perimeter sidewall is a linear bevel tapering outwardly between an outer edge of the substantially planar upper surface and an outer edge of the substantially planar base surface, and wherein the substantially planar base surface is configured to contact the ground attachment surface and not to be embedded in the ground attachment surface;
(b) a centrally-located opening extending through the circular body from the substantially planar upper surface to the substantially planar base surface, wherein the substantially planar upper surface extends between the beveled outer perimeter sidewall and the centrally-located opening; and
(c) the substantially planar upper surface having a non-skid surface.

16. A base plate according to claim 1, wherein the shortest distance between the beveled outer perimeter sidewall and the centrally-located opening is at least about three times greater than the greatest distance across the centrally-located opening.

17. A base plate according to claim 5, wherein the shortest distance between the beveled outer perimeter sidewall and the centrally-located opening is at least about three times greater than the greatest distance across the centrally-located opening.

18. In a separable magnetic attachment assembly including a housing, at least one magnet disposed within the housing, a fastening assembly adapted to couple an object to the housing, and a base plate for reversibly magnetically coupling with the magnet, the base plate comprising:
(a) a body capable of carrying a magnetic current, the body having a beveled outer perimeter sidewall, a substantially planar, non-skid upper surface, and a substantially planar base surface opposing the substantially planar upper surface, wherein the beveled outer perimeter sidewall is a linear bevel tapering outwardly between an outer edge of the substantially planar upper surface and an outer edge of the substantially planar base surface; and
(b) a centrally-located opening extending through the body from the substantially planar upper surface to the substantially planar base surface, the centrally-located opening sized and configured to receive a bolt extending from the magnetic attachment assembly, wherein the substantially planar upper surface extends between the beveled outer perimeter sidewall and the centrally-located opening, and wherein the shortest distance on the substantially planar upper surface from the beveled outer perimeter sidewall to the centrally-located opening is equal to or greater than the greatest distance across the centrally-located opening.

19. A method of attaching a base plate for a separable magnetic attachment assembly to a ground attachment surface, the method comprising:
(a) providing a base plate, including a body capable of carrying a magnetic current, the body having a beveled outer perimeter sidewall, a substantially planar upper surface, and a substantially planar base surface opposing the substantially planar upper surface, wherein the beveled outer perimeter sidewall is a linear bevel tapering outwardly between an outer edge of the substantially planar upper surface and an outer edge of the substantially planar base surface, and a centrally-located opening extending through the body from the substantially planar upper surface to the substantially planar base surface, the centrally-located opening sized and configured to receive a bolt extending from the magnetic attachment assembly, wherein the substantially planar upper surface extends between the beveled outer perimeter sidewall and the centrally-located opening, and wherein the shortest distance on the substantially planar upper surface from the beveled outer perimeter sidewall to the centrally-located opening is equal to or greater than the greatest distance across the centrally-located opening; and
(b) attaching the substantially planar base surface of the base plate to the ground attachment surface so that the base plate is not embedded within the ground attachment surface.