The present invention is directe to a quick mounting of and a quick release of a tool from a magnetic chuck, tool mounting assembly using a combine magnetic and mechanical coupling.

2. Description of the Prior Art.

Heretofore, several tool mounting assemblies for mounting a working tool at the end of a power drill or hand drill where mechanical engaging structure and/or magnetic structure are used to hold a tool to a tool holder and/or a tool holder to a chuck have been propose. Examples of such previously propose assemblies for mechanically or magnetically mounting a tool to a power drill or hand drill are disclosed in the following U. S. Patents: Patent No. Patentee 2,828,131 Appleby 3,970,407 Uffman 4,514,117 Scott 4,692,073 Martindell 4,796,319 Taft 4,900,202 Weinhold 4,995,768 Craft 5,013,194 Weinhold 5,061,123 Broussard 5,191,666 Corbin 5,193,824 Salpaka 5,409,333 Hu 5,417,527 Weinhold 5,470,180 Jore 5,577,426 Eggert et al 5,603,248 Eggert et al 5,651,647 Ray SUMMARY OF THE INVENTION According to the present invention there is provided a magnetic chuck assembly including a conventional chuck having a stem receiving opening and having structure on or in the chuck for imparting a torque to a tool holder; a magnetic

tool holder having a stem and having mating structure for engaging the structure on or in the chuck; and the magnetic tool holder further having holding structure for holding a tool to the magnetic tool holder and magnetic structure associated with the tool holder for holding the magnetic tool holder to the chuck.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded side elevational view of the magnetic chuck assembly of the present invention.

FIG. 2 is an end view of a hex based tool, such as a Phillips screwdriver, which is received into a front end of a magnetic tool holder of the magnetic chuck assembly shown in FIG. 1.

FIG. 3 is an end view of the mushroom shaped front end of the magnetic tool holder of the magnetic chuck assembly.

FIG. 4 is an end view of a stem portion of the magnetic tool holder of the magnetic chuck assembly and is taken along line 4-4 of FIG. 1.

FIG. 5 is taken along line 5-5 of FIG. 1 and shows the front end surface of a keyless chuck.

FIG. 6 is taken along the line of 6-6 of FIG. 1 and is a rear end view of the keyless chuck.

DESCRIPTION OF THE PREFERRED EMBODIMENT (S) Referring now to FIG. 1 in greater detail, there is illustrated therein a magnetic chuck assembly 10 of the present invention which inclues a mushroom shaped magnetic tool holder 12 which is specially configure for being mounted to a specially configure front end face 14 of a keyless chuck 16 which can be of the type made and sold by Jacobs Chuck Technology Corporation of Wilmington, Delaware.

As best shown in FIGS. 1,3 and 4, the magnetic tool holder 12 of the magnetic chuck assembly 10 of the present invention inclues a mushroom shaped front end or generally cylindrical body 18 which has a central opening 20 in a front face 22 thereof which can be specially configure for receiving and holding a tool 24 therein. In the illustrated embodiment, the opening 20 has a hex cross section for receiving a hex in cross section base 26 of the tool 24 as shown in FIG. 1. At the bottom of the opening 20, as shown

in phantom in FIG. 1, is a magnet 28 which is utilized to hold the tool 24 which, in the illustrated embodiment, is a Phillips head screwdriver and which can be a drill bit or a flathead screwdriver. While a magnet 28 is preferred for holding a tool in view of its simplicity and low cost, other tool holding mechanisms can be used, e. g. the tool holders disclosed in U. S. Patent No. 4,692,073, U. S. Patent No.

4,900,202, U. S. Patent No. 5,417,527 or U. S. Patent No.

5,470,180.

On the other or back or rearwardly facing side 30 of the mushroom shaped front end 18 are three (3) projections or bosses 31,32 and 33 which are located approximately 120 2 from each other on and around the back side 30 of the front end or body 18. Extending rearwardly and centrally from the back side 30 is a stem 34 which has, at its rear end, a spline configuration 36 in a star shape, as shown in FIG. 4.

The star shaped hex spline end 36 can be constructed and designed to be received in a hex star opening 38 (FIG. 5) within the keyless chuck 16.

Further, according to the teachings of the present invention, magnetic mounting structure is provided. Thus, equally spaced around the annular back side or face 30 of the front end 18 are three (3) shallow pockets or cavities 41,42 and 43 which, in the illustrated embodiment, are circular in shape and have a shallow depth. These pockets 41-43 are adapted to receive, respectively, three (3) circular or disc shaped or button shaped magnets 45,46 and 47. The magnets 45-47 are fixed in the pockets 41-43 and are adapted to hold the magnetic tool holder 12 against the front end face 14 of the keyless chuck 16.

The front end face 14 of the keyless chuck 16 has formed therein three (3) notches or slots 51-53 equally arcuately spaced apart as shown in FIG. 5. These notches 51-53 are adapted to receive and engage the projections or bosses 31-33 on the back side 18 the mushroom shaped front end 18 as shown in FIGS. 1 and 4. In this way, the magnetic tool holder is held by the magnets 45-47 to the outer end face 14 of the keyless chuck 16 which is made of magnetizable metal, with the bosses or projections 31-33 received in the notches or

slots 51-53 to provide a driving connection between the magnetic tool holder 12 and the front end face 14 of the keyless chuck 16.

Then, of course, a tool such as a Phillips screwdriver 24 is received in the hex opening 20 in the front end face 22 of the mushroom shaped front end 18 of the magnetic tool holder 12 and held therein by the magnet 28.

It will be understood that the star shaped proximal end 36 of the stem 34 can be omitted and only provides a further driving connection between the tool holder 12 and a Jacobs keyless chuck of the type shown in FIG. 1 when the stem 34 is inserted into a bore or stem receiving opening 54 in the keyless chuck 16 and into engagement with the star hex opening 38.

The magnetic chuck assembly 10 including the magnetic tool holder 12 and the specially configure front end face 14 of a metal part of the keyless chuck 16 in cooperation with a tool, such as the Phillips head tool 24, provide a very simple and quick way of mounting different types of tools of different sizes and shapes to a front face 14 of a keyless chuck 16. In this way, once the keyless chuck 16 is mounted on a power drill there is no need to twist or untwist the keyless chuck 16 for inserting different tools into the magnetic chuck assembly 20. Instead, the magnetic tool holder 12 is inserted into the keyless chuck 16 and the workman is"ready to go".

Since no magnets are provided within the bore 54 of the keyless chuck there is no collecting of metal grit or debris.

Any debris that collects on the front or back of the magnetic tool holder 12 or in the opening 20 can be easily cleaned off.

Further, it is to be appreciated that once the magnetic tool holder 12 is mounted to the specially configure front end face 14 of the metal part of the keyless chuck 16, the user of the magnetic chuck assembly 10 only needs to replace the tool 24 at the front end of the mushroom shaped front end 18 of the magnetic tool holder 12 and does not need to twist or untwist the keyless chuck. Simply stated, all the user of the magnetic chuck assembly 10 needs to do is replace the

tool 24.

From the foregoing description it will be apparent that the magnetic chuck assembly 10 of the present invention and in particular the magnetic tool holder 12 have a number of advantages, some of which have been described above and others of which are inherent in the invention. Also, it will be understood that modifications can be made to the magnetic chuck assembly 10 of the present invention without departing from the teachings of the present invention. For example one can provide an assembly 10 that does not have the projections 31-33 and the slots 51-53 and rely only on the magnets 45-47 and the spline end 36 engaging the star shaped hole 38 or omit the spline end 36 and rely only on the magnets 45-47 and the engagement of the projections 31-33 in the slots 51-53.

Accordingly, the scope of the present invention is only to be limited as is necessitated by the accompanying claims.