Abstract:
A quick-connect tool change system for hand drills comprising 
     a) a first, two ended, magnetic bit holder element fitting a chuck, 
     b) at least one second working tool element slidingly fitting over the first bit holder element and having retaining means, 
     The first bit holder element can comprise a natural magnet or an electro magnet selectively energized from a direct current source. A hand drill with a means to provide and transmit electric current to the electro magnet is also provided.

Description:
The present invention relates to accessories for rotating hand tools and more particularly to removable tool elements including an magnetic component. 
     Rapid tool change on rotating hand tools such as drills is a desirable feature because often several successive operation are required to complete a particular work sequence. For example to fasten a hard wood work piece with a screw might require the drilling of a pilot hole, and a clearance hole, reaming a countersink chamfer and finally driving the screw. All this while aligning and holding two work pieces, 
     DESCRIPTION OF THE PRIOR ART 
     One method of rapid tool change is the use of a hand-tightening chuck However, users have found that the forward and backward action of repeated operations loosens the jaws&#39; grip. It is very annoying to have work interrupted because a tool bit fell out of the chuck. Often it is also permanently lost. Also, there is the time required for the repeated change-over and tightening operations because one tool has to be removed to be able to insert the other. A variety of reversible tools have been proposed where an adaptor is held in the chuck and a dual ended tool with a screwdriver bit and a drill bit is alternately used by flipping the tool end over end. As an example is here cited U.S. Pat. No. 3,023,015 to Pankow. A version where the flip-over tool is detached from the adaptor is marketed by several manufacturers. All share the disadvantage of adding to the length of the overall system. Usually only one end of the tool holder is changeable and fully magnetized. Rodin in U.S. Pat. No. 3,484,114 endeavors to drive a tool with the holes of the chuck with a second tool held ready in the jaws. A number of attempts have been made to drive a second drill by means of the screw driver bit in the chuck. Two such devices are shown in U.S. Pat. No. 3,973,784 to Smith, U.S. Pat. No. 4,525,111 to Gutsche and U.S. Pat. No. 5,722,805 to Giffin, the latter using the familiar spring loaded blocking plate previously used in caulking guns and pipe clamps to secure the second tool and having four moving parts made up of seven components. The tools based on U.S. Pat. No. 4,413,937 to Gutsche and sold under the trade name Chuck-Mate use the sides of the chuck jaws to drive the second tool, in effect fitting two tools into the chuck at the same time. All these prior art devices have been cited to show how the here disclosed invention can enhance their performance. The present invention synergistically improves the above tools in the following manners: It shortens the length of dual-ended tools fitting into an adaptor by making the adaptor shaft hollow right to the end and thereby allowing the tool to reach deep into the chuck. The present invention&#39;s magnet combined with its two magnetized bits allows the tool to be held by magnetic force in the chuck, even if the jaws happen to have somewhat loosened, thus eliminating the possibility of unexpected tool loss. The Rodin, Giffin and other devices can be simplified by synergistically using the magnet&#39;s force to accomplish the above mentioned tasks and simultaneously helping to actuate the retaining mechanism of the additional tool. 
     SUMMARY OF THE INVENTION 
     It is therefore the object of the present invention to provide a quick-change tool element wherein at least two or more working tools are simultaneously attracted, held and served by one magnet. 
     A further object of the invention is to prevent loss of tool elements from the chuck of a hand drill where the grip of the jaws has somewhat slackened by bringing a magnetized bit into contact with the interior of the drill, while simultaneously holding a screw or other object by magnetism at the other, exposed end of the tool element. 
     A further object of the invention is to economically provide a strongly magnetized element for a tool system that will synergistically fulfill five magnetic functions. 
     Another object of the invention is to provide a shortened quick change tool system by devising a hollow-shafted adaptor with a deep or through hole that allows longer tool elements to disappear deep into the chuck. 
     A further object of the invention is to provide a quick change tool system with a reduced number of loose bits by using a dual-ended, dual-magnetized basic element. 
     A further object of the invention is to provide a magnetic bit holder with an electro-magnet, giving the operator the possible choice to activate or de-activate the retaining means of the various elements by use of a switch operated by the one hand also holding the drill. 
     Another object of the invention is to provide a hand drill that is adapted to allow the operator to selectively retain slide-on tools by means of current provided from the hand drill. 
     Another object of the invention to provide both the fastest, most versatile and least costly tool change systems for hand drills. 
     The objects of the present invention are accomplished by the following preferred embodiments: 
     In one embodiment there is provided an first element for a tool system with an elongated member that is adapted to be gripped by the jaws or holding means of a tool holder or chuck, has at least one magnet disposed to be exposed to the ends of the elongated member, the magnet is disposed and adapted to simultaneously to attract the retaining means of second tool elements, hold two working bits, attract the band drill machine at one end and selected objects on the other end of the fist element. 
     In another preferred embodiment a second tool element is provided that slides over the first element of a tool system and is adapted to receive torque forces from the chuck of the drill machine. 
     In one embodiments the second tool element is equipped with tongues or prongs that are adapted to receive torque forces from the jaws and synergistically act as magnetically attractable retaining means. 
     In another preferred embodiment the outer surface of the first element for a tool system is shaped to transmit torque forces to a second tool element, and the second tool element is adapted to receive torque forces from the first element for a tool system and has means to be retained or locked on the first element for a tool system. 
     In another preferred embodiment of the invention the functioning of the retaining or locking means of the second tool element is at least in part helped by the action of the magnet of the first element of a tool system 
     In one embodiment of the second tool element, the retaining means that is magnetically assisted is at least one tongue or prong. 
     In another embodiment the retaining means that is magnetically assisted is a sap-in ball. 
     In another embodiment of the second tool element the retaining means is a magnetically activated loose washer. 
     In another preferred embodiment there is provided a third adaptor element that has a deep or through hole and is adapted to fit into —and to receive torque from— a chuck and is adapted to receive the first element of a tool system inside the deep hole and to transmit torque forces from the chuck to the first tool element. 
     In another preferred embodiment the third adaptor element has a cylindrical or round hole and at least one T-shaped slot that engages at least one pin on a first element of a tool system that,—upon rotation—, locks, and together with a magnet synergistically serve as retaining and torque transferring means. 
     In another embodiment the deep hole of the third adaptor element is of non-circular or hexagonal cross section and can transfer torque forces to a first element of a tool system that has a non circular or hexagonal shaped cross section. 
     In another embodiment the third adaptor element has retaining means in the form a ball and sliding sleeve arrangement to positively hold a first element of a tool system. 
     In another embodiment the magnet of the first element of a tool system is an electro-magnet, that either automatically works during the rotation a hand drill or is triggered separately and allows the operator to selectively activate the magnetically attractable retaining means of the various elements of this invention. 
     Another embodiment of the invention is an electric hand drill machine equipped to selectively transmit electrical current to a first element of a tool system with an electro-magnet. 
     Another preferred embodiment is the combination of two or three of the disclosed elements of a tool system. 
     These and other advantages of the present invention will be apparent in the following description: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is illustrated by way of example in the following drawings, wherein 
     FIG. 1 is a perspective, partially cutaway view of an element of a tool system in a chuck, 
     FIG. 2 is a perspective view of the combination of two elements of a tool system, 
     FIG. 3 is a perspective partial cut-away view of the combination of two elements of a tool system, 
     FIG. 4 is a sectioned view of the combination of two elements of a tool system held in a chuck, 
     FIG. 5 is a partially cut-away view of two elements of a tool system in a chuck and 
     FIG. 6 is a partial cut-away view of a parts of a hand drill and three tool elements. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now in detail to the drawings. 
     In FIG. 1 is shown a first element for a tool system  10  held in tool holder or chuck  11  by means of jaws  12  that are the holding means able to transfer torque and lateral forces to the outer surface  13  of elongated member  14  of element  10 . Elongated member  14  of this embodiment and those in the following illustrations are understood to be made from a the non-magnetic materials such as stainless steel well known to those skilled in the art. The chuck  11  is fastened to a hand drill machine  26  by screw  15  that is a steel component magnetically attractable to magnetic forces emanating from a magnet  16  and projected at this point along the axis of rotation  17  to working tools or bits  18  and  19 . The bit  18  is a countersink with the customary ¼″ hex shank that is held in cavity  20  at one end of the elongated member  14 , whereas the working tool  19  is a screw driver bit held in cavity  21  at the other end of elongated member  14 . Central magnet  16  is shown to be a single unit, but could be made up of several segments, depending on the magnetic strength requirements. Central magnet  16  and cavities  20  and  21  are adapted to favor direct contact between magnet  16  and the bits  18  and  19  or any other selected working tools. Magnet  16  is seen to be secured internally in elongated member  14  by compression forces generated by pressure resulting from the creation of optional indentations  22  in outer surface  13 . Indentations  22  can synergistically serve as grip portions for the retaining means of further second tool elements. It is known to those skilled in the art that magnetic force lines are approaching a direction normal to the axis of rotation  17  near the poles of magnet  16 , creating the strongest inward forces near that area at the ends of the magnet  16 . It is preferred that indentations  22  align with locations where magnetic force lines are normal to the axis of rotation  17 . Holes  23  are co-rotating with chuck  11 , are part of its&#39; tightening means and are together with jaws  12  parts of the chuck that are useful for transferring forces to further second tool elements. A wood screw  25  is an example of an object that might be attracted simultaneously together with machine screw  15  by the action of magnet  16 . Working tools such as counter sink  18  or taper drills (shown later) do normally not resist removal from a drilled hole, and the force of magnet  16  should be sufficient to hold them in cavity  20  during the whole reaming operation, including the withdrawal. 
     In FIG. 2 is shown second tool element  30  that is adapted to enter in a sliding fit over the outer surface  13  of first element of a tool system  10 . Second tool element  30  has a drill  39  on one end and tongues  31  on the other end Prongs  31  are disposed on second tool element  30  substantially parallel to axis of rotation  17  and are the retaining mans to selectively lock second tool element  30  on first element  10  and synergistically serve as the means to receive torque forces from jaws  12 . At least one of tongues  31  is seen to be provided with optional protrusions  32  that are adapted to selectively engage the outer surface  13  at optional indentations  22  or surface protrusions  33 . The prongs  31  are made from a magnetically attractable material such as mild steel and accordingly their contact with surface  13  is facilitated or assisted at this point by the action of magnet  16 . While the dimensions of optional indentations  22 , surface protrusion  33  or protrusions  32  are shown to be substantial, it is understood by those skilled in the art that they can have various dimensions and that even microscopic surface roughness significantly increases the coefficient of friction which allows the second tool element  30  to be retained on elongated member  14  during work. Tongues or prongs  31  are seen to have raised portions  34  that allow sliding ring  35  to selectively exert a force away or toward the axis of rotation  17 . Sliding ring  35  is shown in locking position  36  where prongs would be near magnet  16 . In position  37  ( shown in phantom lines), ring  35 , during removal of second tool element  30 , would exert a lifting force away from the axis of rotation  17  on the free ends of prongs  31  having protrusions  32 , this by lever action about the fulcrum that is formed by contact area  38 . It is apparent that prongs  31  can also be adapted to pass external of chuck and selectively engage holes  23 . These, like jaws  12  are co-rotating with the drill machine and are useful to impart rotation or torque forces to element  30 . It can be seen that in this combination the magnet  16  fulfills  5  synergistic functions. First, it holds simultaneously  2  removable bits  18  and  19 . Secondly, the element  10  is magnetically held in chuck  11 . Thirdly, it attract and holds second element  30  along axis of rotation  17  and fourth, it pulls on retaining means  31  in a direction toward the axis of rotation  17 . A fifth function occurs when fastener  25  or any other magnetically attractive object such as a version of second tool element  30  is selectively held, near bit  18  and is lifted at the operators convenience. It is apparent of course that the tongues  31  define a cavity with hexagonal cross section and that second tool element will also function with a hexagonal shaped first element shown in the next drawing. 
     In FIG. 3 is illustrated a version of second tool element  40  that is shown to slide over first element for a tool system  41 , one that is similar to the previously shown first element  10 . However in this embodiment the elongated member  43  is seen to be of hexagonal cross section, so that the outer surface  44  has the means to transmit torque forces to the second tool element  40 . Jaws  12  (shown partially and in phantom lines), hold one end of first element of a tool system  41 . The torque forces from jaws  12  are thus transmitted from the hand drill to second tool element  40 . This is accomplished by hexagonal cavity  45  seen in phantom lines, that is second tool elements&#39; means to receive torque forces from first element  41 . Aligned with magnet  46  is curved and loose washer  47  that is the retaining or locking means of second tool element  40 , designed to block removal of it from first element  41  when pull is exerted on working tool  48 . Such pull and resistance is frequently experienced when a deep pilot hole is drilled in hard wood. Pivoting washer  47  straddles in a loose fit the outer surface of second tool element  40 . Magnetic forces acting at various angles to axis of rotation  49  are understood to help move curved washer  47  into a position that is as far away from normal to axis of rotation  49  as play in notches or holes  50  and  51  allows. Holes  50  and  51  are seen to reach into the hex cavity  45  and make contact with outer surface  44  of first element  41 and washer  47  possible. In such a magnetically induced screwed position of the retaining means or washer  47 , interlocking of elongated member  43  and second element  40  occurs. This retaining or locking is facilitated when the rim  52  of notch  50  urges curved washer  47  along when second tool element  40  is pulled in the direction toward tool  48 . A sliding ring  53  is designed to touch washer  47  near notch  51  and serves to override the action of magnet  46  and thereby allow the moving of washer  47  into a position more or less normal to the axis of rotation  49 , thereby freeing second tool element  40 . Sliding ring  53  can be an intregal part of cover  54  that shields the curved washer  47 . It is evident that the washer  47  will be pulled into the ready-to-lock position by the action of magnet  46  and then fully locked by any pulling action on working tool  48 . This magnetically actuated design reduces the retaining or locking mechanism to as little as two moving parts, a hundred percent improvement over the prior art devices. Indentations  55  in outer surface  44  are an optional feature to engage washer  47  in selected positions with outer surface  44 . They have proven useful in making the locking retaining means less vulnerable to the results of wear. 
     In FIG. 4 is illustrated the second tool element  60  in combination with first element for a tool system  41 . The outer surface  44  is adapted to enter in a sliding fit hexagonal cavity  61 , that holds in its ¼″ hex hole portion the working tool  62  secured by set screw  63 . The second tool element  60  has as principal retaining or locking means balls  64  that could be aided in their contact with surface outer  44  by magnet  46 . Part of the interior cavity  61  is conically shaped, defining sloping portion  65 . The balls  64  are held in a loose fit in second tool element  60  in such a way that movement of surface  44  either loosens or tightens the balls  64  as they either roll freely or are jammed between outer surface  44  and slope  65 . A sliding ring  66  has extension  67  that communicates with the balls  64  and allows the operator to free the jammed balls  64  by pulling ring  66  toward the working tool  62 . An optional spring  68  would keep extensions  67  from interfering with contact between balls  64 , slope  65  and outer surface  44 . It is apparent that through the use of indentations  55  on surface  44 , with a ball-type retaining or locking means, the sloping portion  65  could be dispensed with and that the balls  64  could be held in the indentations  55  by a structure equivalent to the optional lip portion  69 . When sliding ring  66  is pulled in a direction fully away from tool  62 , lip or ring structure  69  would positively lock balls  64  near magnet  46  in indentations  55 , as is shown in separate phantom lines. In either case the disclosed invention provides many synergistic actions of the cooperating parts. 
     In FIG. 5 is shown the combination of an adaptor element  70  with the first element of a tool system  80 . Third adaptor element  70  has deep cavity  71  that allows it to accept in a sliding fit the outer surface  83  of elongated member  82 . Cavity  71  is seen here to be an end-to-end round hole and reach fully into Chuck  11 , allowing access to magnetically attractable screw  15  by tool bit  84 . However, in another, here not shown, version of cavity  71 , for structural reasons for example, a thin wall (not shown) could be left at the end to allow tool bit  84  to butt against. In either case, cavity  71  reaches deep into the chuck  11 . Screw  15  is part of a drill machine (not fully shown). Jaws  12  (shown partially and in phantom lines) grip outer surface  73  and are used to transfer torque forces. Optionally, outer surface  73  could be a prism with hexagonal cross section or have three or six lengthwise indentations to both strengthen the walls and favor torque transfer from jaws  12  to third adaptor element  70 . In this illustration, tool bit  84  is the well known self centering “VIX” bit developed by the S.E. Vick Tool Co. of Lakeville Minn. Its hex shaft  87  and also the screw driver bit  88  are held by magnet  85  that is exposed to the two “hex” end cavities  89  of second tool element  80 . Like counter sink  18 , the VIX bit  84  does not require fastening by a set screw, since its penetrating drill bit is spring-loaded, which will extract itself from the drilled hole by spring pressure alone. However, because of its&#39; considerable length, the VIX bit normally projects excessively from the solid-shafted holders of the prior art, contributing to its wobble. In the here disclosed hollow third adaptor element  70  with its deep or full length end-to-end cavity  71 , the longer drills, such as the VIX bit  84 , are accommodated with at least 50% reduction in overall length. Added to this is the convenience of being able to easier clean the through hole  71  of accumulated debris and of course being able to reverse the ends of unit  80  without having to loosen or tighten the Chuck  11 . While the central magnet  85  provides magnetic forces that hold first element for a tool system  80  inside chuck  11 , more positive locking of first element for a tool system  80  is provided during drilling and withdrawing by the pin  86  on outer surface  83 . Other pins might be provided, but are not visible in this rendering. Pin  86  as retaining or locking means is designed to cooperate with the T-shaped slot  74  in the wall of third adaptor element  70 . More than one slot  74  might be provided to match the number of pins  86 . It is seen that upon rotation of chuck  11 , pin  86  will be forced into niches  75  which thereby become the retaining or locking means of third adaptor element  70 . Pins  86  will be urged to remain there during forward or reverse operation of the machine. Synergistically, niches  75  are the means to transfer torque forces from third tool element  70  to first element for a tool system  80 . Pin  86 s easily slides out of slot  74  via passages  76  when the machine is at rest. Alternately passage  76  would also transfer torque forces to pin  86 . More than one niche  75  is seen to be provided staggered in the parallel to axis of rotation  49 , this to accommodate the difference in length of various bits such as  84  and  88  and yet reach close to the magnetically attractable screw  15 . It is evident that the other retaining or locking means disclosed in this invention could be adapted and disposed on third tool element  70  to replace the function of the shown pin  86  slot  75 —magnet  85  combination Such an alternate embodiment would be particularly useful if a hex female and hex male arrangement (not shown) is chosen for the cavity  71  and outer surface  83  respectively. It is further apparent that there is room on the free end of first element of a tool system  80  for modified versions of the previously described second tool element  30 . Pin  86  would then synergistically transfer torque to prongs  31  Second tool element  40  could be adapted to this use by introducing an interior groove or key way that engages pin  86 . In these (here not illustrated) combinations  3  working tools could be served by adapter element  70 . Users of this invention are given accordingly the choice to combine at their convenience the various features to best suit their particular applications. 
     In FIG. 6 is shown first element of a tool system  90  slidingly fitting into third adaptor element  100 . Its&#39; through hole or deep cavity  101  has a hexagonal cross section and is the means to transfer forces to elongated member  91  with hexagonal outside cross section. It is apparent of course, that any non-circular cross section of cavity  71  and matching non-circular cross section of elongated member  91  would effectively serve as a means to transfer forces. As examples of such cross sections might be cited the square and star-shaped drivers used in the industry. Third adaptor element  100  is grasped or gripped by jaws  102 , the holding means for tool holder or chuck  103  (both shown partially and in phantom lines). Machine screw  104  fastens chuck  103  to a hand drill machine (not fully shown). An insulated plastic bushing  106  has encased conducting ring  107  that receives current via sliding contact  105 , and is exposed at its other end and inside chuck  103  to contact wire  92  of first element  90 . Wire  92  has properly insulated portions and leads to coil  93  surrounding magnet core  94 . The other terminal  114  of coil  93  is grounded with contact  95  via the joining metal components of the hand drill machine to a low voltage power supply or battery  110 . As might be the case with a cordless drill, battery  110  might be the hand drills&#39; rechargeable power pack. Switch  108  might be lied to the trigger switch that is actuating the rotation of the main motor, or be a separate, detached unit, useable only on command distinct from the action of hand drills&#39; motor.(not shown). Clearance hole drill  97  is held in counter bore  96  by a set screw. Counter bore  96  and screw driver bit  98  are seen to be held in the ¼″ hex cavity of elongated member  91 . Static friction holds first element for a tool system  90  in the well fitting hex cavity  101  of third adaptor element  100 . During drilling operations, a surge of direct current should energize and magnetize the core  94 , causing it to powerfully attract both bit  98  and screw  104 . Magnet core  94  and coil  93  are conceived to generate enough pull to overcome the resistance to withdrawal of drill  97  from a finished, drilled hole. Skilled operators always keep hand drills rotating while attempting to withdraw drills from their drilled holes, because dynamic friction is always less than static friction. Upon release of switch  108 , and end of rotation of chuck  103 , the operator can now easily, without having to cope with the magnetic force, proceed to put the screw driver  98  to work after rotating it to the front of the tool system. The electrical components of this illustration are not shown to proportion and only by using the appropriate symbols. It is believed that those skilled in the art are well capable to formulate workable systems using the here thus disclosed information. Third adaptor element  100  has an optional locking or retaining means in the form of ball  111  with which to positively retain second tool element  90 . An optional sliding sleeve  112  is shown to depress ball  111  in the locked position. Lip or internal recess  113  on sleeve  112  serves to free ball  111  and its function was shown as optional structure  69  on second tool element  60 . A version of the second tool element  60  with locking balls  64  is seen to be slid onto the free portion of elongated member  91 . Element  60  carries the pilot hole drill  99  required to fully prepare a screw hole that was started by the use of counter bore  96 . It can be seen that balls  64  and  111  will be strongly drawn into contact with elongated member  91  by the action of electro-magnet  94 . Optional and previously described indentations  115  will enhance the resulting retaining action. The here shown combination of the first element for a tool system  90  held in third adaptor element  100 , but in turn supporting second tool element  60 , shows the versatility of this magnetic tool change system. It is obviously also that it will function without the optional hand-actuated positive locking means  112  or notches  75 . The use of electro-magnet  94  further allows the operator to choose between quick but moderate retaining by magnetism alone, or positive locking by use of the ball and sleeve arrangements possible on both the second tool elements and third adaptor elements. 
     The herein shown few embodiments are but examples of the various ways in which the disclosed invention can be produced and used. The present invention shall be considered defined by the following claims: