Abstract:
The present disclosure describes and teaches a drill safety system including a magnetic unit, a vacuum unit, and an improved hole saw drill set. The various parts of the drill safety system may be used individually or in combination with one another. The user may use the magnetic unit to surround the drilling site so that metal drill shavings on the drill surface may be collected by the magnetic unit. In addition, the magnetic unit includes a flippable top mechanism, allowing convenient disposal of the debris. The vacuum unit is fitted to the inner surface of the drilling site, collecting debris that fall through. The improved hole saw prevents over-penetrating by the drill, reducing the likelihood of damaging equipments underneath the drill site. This makes the drill particularly suitable for drilling holes during electrical work.

Description:
CLAIM OF PRIORITY 
     This application claims the priority of U.S. Ser. No. 61/777,635 filed on Mar. 12, 2013, the contents of which are fully incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a drilling safety system and more particularly relates to a safety system specially designed to prevent drill shaving and debris from damaging the surrounding equipments and harming the worker. 
     BACKGROUND OF THE INVENTION 
     For many manufacturing, maintenance, and repair projects, drilling is an indispensible part of the operation. Under some circumstances, drilling can become hazardous to the person conducting the drilling, the workpiece, and/or the equipments and environment surrounding the drilling site. If essential safety devices cannot be provided, or if proper safety procedures cannot be followed, accidents during drilling may happen, causing significant damages and threatening the worker&#39;s wellbeing. 
     One example for hazardous drilling operations is drilling conducted during electrical work. The electricians are sometimes required to drill on the metal housing of switchgears, which in many instances have to stay “live”—with the electricity still on during the drilling process. Such requirements are not rare, especially for the maintenance and repair work conducted for companies, factories and hospitals, where the continuous provision of electricity is essential. However, the metal shavings and debris resulted from drilling are very hard to collect and such shavings and debris may disperse into the live switchgear, causing short-circuiting or even explosion. Most electricians use make-shift arrangements to collect the shavings and debris. For example, one worker may reach inside the housing of live gear and hold a cardboard box under the drill site while another worker drills through the top. However, such temporary solutions are far from complete and fully effective. 
     Some devices and systems have been developed to address the danger associated with drilling debris. These designs, however, show shortcomings in one aspect or another. For example, U.S. Pat. No. 6,974,048 (&#39;048 patent) discloses a safety tool that includes magnets and an outer non-conductive sheath encompassing an inner bag. A purpose of the tool is to provide safety for the operator while drilling or cutting into electrical/electronic enclosures, such as switchgear. The tool is constructed so that an operator can perform a task while preventing any conductive debris caused by this task to come in contact with any electrical parts. The top portion of the tool magnetically attaches to the inside of the switchgear structure. The bottom portion of the tool, which is coupled to the top portion by the non-conductive sheath, collects and magnetically contains the debris, such as shavings from drilling into the structure. The debris is collected in the inner bag, which can easily be removed from the tool for disposal of the debris. 
     This design of the &#39;048 patent, however, has at least two significant disadvantages. First, while much all of the debris is generated on the drilling surface where drilling is initiated, such debris is not properly collected. It should be noted that the majority of the shavings stay at the drilling side and the design taught by the &#39;048 patent does not address these shavings at all. The device disclosed by the &#39;048 patent only collects the shavings after the drill bit has penetrated the workpiece. The shavings on the side of the drill are not collected and these shavings have the potential to cause significant damage to the surrounding equipment as well as the worker himself/herself. More importantly, the tool disclosed by the &#39;048 patent requires the worker to place his/her arm into the housing of live gear to attach the tool to the inner surface of the housing. Similar action is also required to remove the tool from inside the housing of live gear. Such attachment/removal processes significantly increase the chance that the worker would be electrocuted, accidentally drop the bag full of shavings/slugs into the gear, or come in contact with energized parts while holding the bag full of shavings. Therefore, the design by the &#39;048 patent is both unreliable and unsafe. 
     The hazards of drilling into live electrical equipment involve at least (1) the danger of metal shavings and the slug created by the hole saw entering the housing of the gear during the drilling process and after the drilling process is completed from the drilling side; (2) the danger of the hole saw being released from the drill chuck during the drilling process and falling into the live equipment; (3) the danger of a worker reaching into the live equipment to place equipment inside the housing of live gear under the drilling area to catch debris and removing it, and (4) the danger of dropping the conductive metal shavings accidentally inside the housing of live gear once such shavings are collected. 
     The current invention addresses all the concerns herein discussed and properly collects all the shavings generated in a drilling process without requiring a worker to reach inside the house of live gear. The devices taught by the current invention may be used in various types of drilling operations and are particularly useful for drilling conducted during electrical work. In summary, various implements are known in the art, but fail to address all of the problems solved by the invention described herein. The preferred embodiments of this invention are illustrated in the accompanying drawings and will be described in more detail herein below. 
     SUMMARY OF THE INVENTION 
     The present invention discloses a drill safety system, which may include three parts that can be used individually or in combination. The three parts include: a magnetic unit, a vacuum unit, and an improved hole saw drill set. The magnetic unit may comprise a magnet core and a flexible and openable cover shielding the magnetic core. The vacuum unit may comprise a collecting cup and a connecting tube, wherein the collecting cup and the connecting tube are hollow inside and are connected. The key feature of the hole saw drill set is that it has stopper flange extending from the front periphery of the hole saw arbor, wherein the stopper flange is positioned right behind and abutting the hole saw and blocks advancement of the drill set when the stopper flange abuts a workpiece. 
     As indicated above, the three parts of the drill safety system may be used individually. However, it is preferable that the parts, especially the magnetic unit and the vacuum unit are utilized in combination. The current invention is particularly useful for drilling on metal workpieces, especially the housing of switchgear, which are often “live” and may be hazardous to work with. Here, for the purpose of providing a clear description, the surface of the workpiece that engages the drill bit is considered a “drilling surface,” and the surface opposite to the drilling surface is defined as “inner surface.” The location on the workpiece that engages the drill bit is the “drilling site.” The terms “shavings” and “debris” generally refer to small pieces of metal or other materials generated by the drilling process. These terms are essentially synonyms and may also refer to “scraps,” “fragments,” “powders,” and “crumbs” that are produced during drilling. 
     Before drilling starts, the magnetic unit is placed on the drilling surface, and around and/or adjacent to the drilling site. In a preferred embodiment, the magnetic unit has a ring or annulus shape, allowing it to surround the drilling site. The cover of the magnetic unit may comprise a unit base and a flippable top; the magnet core may be placed on the unit base; and the flippable top may be flipped up to allow the magnet core to be removed. During drilling, the metal shavings on the drilling surface are pulled towards the magnetic unit and attach to the cover, which is preferably non-magnetic and non-conductive. After drilling, the flippable top is flipped up, allowing the magnet core to be removed so that the metal shavings can no longer attach to the cover. The user may then easily discard the shavings. To ensure the physical robustness of the magnetic unit, a support structure may be included to provide physical support to the magnetic unit. 
     The vacuum unit is used to collect the shavings from the inner side. After initial penetration by the drill bit, shavings start to be generated at the inner surface. Such shavings are particularly dangerous because equipment such as switchgear may be damaged if the shavings fall into the equipment. The collecting cup of the vacuum unit may have a lower cup body and a cup rim, wherein the cup rim may fit on the inner surface. The cup covers the drilling site, providing a complete shielding and collecting structure that ensures all shavings from the inner surfaces are properly gathered. 
     The vacuum unit may further include a first connector, a second connector and a handle element having a handle tube and a handle, wherein the first connector, the second connector, and the handle tube are hollow inside, and the collecting cup, the first connector, the connecting tube, the second connector, and the handle tube are sequentially connected, forming a through channel. Furthermore, the vacuum unit may be connected to a vacuum motor providing suction power, allowing shavings on the inner surface to be collected. In one embodiment, the connecting tube is rigid, ensuring more toughness and robustness. In another embodiment, the connecting tube is flexible, allowing better adjustment. A user may take hold of the handle and manually press the collecting cup to the inner surface. Alternatively, the cup rim may include magnets so that the collecting cup can magnetically attach to the inner surface. The first connector and the second connector are structures that provide more flexibility to the design of the vacuum unit and these structures may have different length and twisting angles. By adjusting the first connector and the second connector, a user may reconfigure the vacuum unit to avoid pressing against the equipments in the workpiece. 
     The current invention may also include an improved hole saw drill set that includes a stopper flange. The conventional hole saw is a cylinder structure wherein the front end of the cylinder facing the workpiece has sawteeth that may cut through the workpiece to produce a hole. For the conventional hole saw drill set, there is no structure that stops the advancement of the hole saw against the workpiece even after the hole saw has completely passed the drilling surface. Such a design, however, puts performance above safety because while the hole saw can cut holes deeper than its entire length, over-penetration may result in damage to the equipment inside the inner surface by the drill bit. The conventional design is particularly dangerous when drilling on the housing of live switchgears. The current improved hole saw drill set includes a stopper flange attached to the hole saw arbor and positioned right behind and abutting the back end of the hole saw, blocking the advancement of the drill set when the hole saw cylinder has cut into the workpiece. Such a design prevents over-penetration and protects the inner structures of the workpiece. 
     In general, the present invention succeeds in conferring the following, and others not mentioned, desirable and useful benefits and objectives. 
     It is an object of the present invention to provide a drill safety system that is safe and easy to use. 
     It is another object of the present invention to provide a drill safety system having a magnetic unit capable of collecting metal shavings on the drilling surface. 
     It is another object of the present invention to provide a drill safety system having a magnetic unit with an openable cover that is non-magnetic and non-conductive. 
     It is another object of the present invention to provide a drill safety system having a magnetic unit that makes disposing the metal shavings easier. 
     Yet another object of the present invention is to provide a drill safety system having a vacuum unit that can collect the shavings on the inner surface. 
     Yet another object of the present invention is to provide a drill safety system having a vacuum unit that is easy to adjust and reconfigure. 
     Yet another object of the present invention is to provide a drill safety system that requires a minimum of maintenance. 
     It is another object of the present invention to provide a drill safety system that is robust and durable. 
     Yet another object of the present invention is to provide a drill safety system having an improved drill set with a stopper flange. 
     Yet another object of the present invention is to provide a drill safety system having an improved drill set with a stopper flange that prevents damages to the structures within the workpiece. 
     Still another object of the present invention is to provide a drill safety system that is inexpensive. 
     Still another object of the present invention is to provide drill safety systems having different parts that can be used individually and in combination with one another. 
     It is a further object of the invention to provide a drill safety system that is easy to manufacture. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a top perspective view of a vacuum unit of the drill safety system. 
         FIG. 2  shows a bottom perspective view of the vacuum unit of the drill safety system. 
         FIG. 3  shows a top perspective view of a magnetic unit of the drill safety system when the flippable top is set in place. 
         FIG. 4  shows a top perspective view of the magnetic unit of the drill safety system when the flippable top is flipped over. 
         FIG. 5  shows a top perspective view of the magnetic unit of the drill safety system when the flippable top is flipped over and the magnets are removed. 
         FIG. 6  shows a top perspective view of an improved drill set of the drill safety system. 
         FIG. 7  shows a side view of the improved hole saw drill set of the drill safety system. 
         FIG. 8  shows a side sectional view of all components of the drill safety system when the system is in use. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The preferred embodiments of the present invention will now be described with reference to the drawings. Identical elements in the various figures are identified, as far as possible, with the same reference numerals. Reference will be made in detail to embodiments of the present invention. Such embodiments are provided by way of explanation of the present invention, which is not intended to be limited thereto. In fact, those of ordinary skill in the art may appreciate upon reading the present specification and viewing the present drawings that various modifications and variations can be made thereto without deviating from the innovative concepts of the invention. 
       FIG. 1  shows a top perspective view of a vacuum unit of the drill safety system. Shown in  FIG. 1  is the vacuum unit  50  having a collecting cup  60 , a first connector  70 , a second connector  75 , a connecting tube  80 , and a handle element  85 , wherein the collection cup  60  has a lower cup body  62  and an enlarged cup rim  63 , and the handle element  85  has a handle tube  86  and a handle  87 . The collecting cup  60 , the first connector  70 , the connecting tube  80 , the second connector  75  and the handle tube  86  are all hollow inside and are sequentially connected, forming a through channel for the movement and collection of drill shavings. 
       FIG. 2  shows a bottom perspective view of the vacuum unit of the drill safety system. Shown in  FIG. 2  is the vacuum unit  50  having a collecting cup  60 , a first connector  70 , a second connector  75 , a connecting tube  80 , and a handle element  85 , wherein the collection cup  60  has a lower cup body  62  and an enlarged cup rim  63 , and the handle element  85  has a handle tube  86  and a handle  87 . The collecting cup  60 , the first connector  70 , the connecting tube  80 , the second connector  75  and the handle tube  86  are all hollow inside and are sequentially connected, forming a through channel for the movement and collection of drill shavings. 
       FIG. 3  shows a top perspective view of a magnetic unit of the drill safety system when the flippable top is set in place. Shown in  FIG. 3  is the magnetic unit  10  having an outer cover  20 , wherein the outer cover has a unit base  24  and a flippable top  27 . The inner structures of the magnetic unit  10  are shielded from view. The magnetic unit  10  is generally a ring or annulus structure, especially if viewed from the top. 
       FIG. 4  shows a top perspective view of the magnetic unit of the drill safety system when the flippable top is flipped over. Shown in  FIG. 4  is the magnetic unit  10  having an outer cover  20 , wherein the outer cover has a unit base  24  and a flippable top  27 . The flippable top  27  is flipped up, showing the inner magnets  30 , the magnet connectors  33 , and the support ring  40 . As indicated by  FIG. 3 , the magnets  30  are fully covered when the flippable top  27  is flipped down. As shown in  FIG. 4 , the magnets  30  are placed around the support ring  40  and on the unit base  24 . 
       FIG. 5  shows a top perspective view of the magnetic unit of the drill safety system when the flippable top is flipped over and the magnets are removed. Shown in  FIG. 5  is the magnetic unit  10  having an outer cover  20 , wherein the outer cover has a unit base  24  and a flippable top  27 . The flippable top  27  is flipped up, showing the inner magnets  30 , the magnet connectors  33 , and the support ring  40 . The magnets  30  are removed from the unit base  24 . 
       FIG. 6  shows a top perspective view of an improved drill set of the drill safety system. Shown in  FIG. 6  is the drill set  90  having a pilot bit  93 , a hole saw arbor  94 , and a hole saw  95 . The key feature for this embodiment is that the hole saw arbor  94  includes a stopper flange  96  positioned right behind and abutting the hole saw  95 . 
       FIG. 7  shows a side view of the improved drill set of the drill safety system. Shown in  FIG. 7  is the drill set  90  having a pilot bit  93 , a hole saw arbor  94 , and a hole saw  95 . The key feature for this embodiment is that the hole saw arbor  94  includes a stopper flange  96  positioned right behind and abutting a back end  98  of the hole saw  95 , defining a hole saw length  99  measured from a front end  97  to the back end  98  of the hole saw  95 . Such an improvement limits the depth of the hole resulted from drilling with the drill set  90  to the hole saw length  99 , preventing unintended over-drilling that may damage the equipment underneath the drilling site. 
       FIG. 8  shows a side sectional view of all components of the drill safety system when the system is in use. Shown in  FIG. 8  is a drill  100  equipped with the improved drill set  90  having a pilot bit  93  and a hole saw  95 , which includes bit stopper flange  96 . Also shown in  FIG. 8  are the magnetic unit  10  and the vacuum unit  50 , wherein the magnetic unit  10  comprises an outer cover  20  having a unit base  24  and a flippable top  27 , inner magnets  30  with magnet connectors  33 , and a support ring  40 ; the vacuum unit  50  comprises a collecting cup  60 , a first connector  70 , a second connector  75 , a connecting tube  80 , and a handle element  85 ; and the collection cup  60  has a lower cup body  62  and an enlarged cup rim  63 , and the handle element  85  has a handle tube  86  and a handle  87 . As shown in  FIG. 8 , the collecting cup  60 , the first connector  70 , the connecting tube  80 , the second connector  75  and the handle tube  86  are all hollow inside and are sequentially connected, forming a through channel for the movement and collection of drill shavings. 
     In  FIG. 8 , drilling is being conducted on a metal board  200 , which has a drilling surface  210  that engages the pilot bit  93  and the hole saw  95 , as well as an inner surface  220  that is the opposite of the drilling surface  210 . In addition, the location on the board  200  that initially engages the drill bits are generally termed a drill site  240 . The board  200  is intended as an example for the workpieces on which drilling can be conducted. Workpieces having different shapes, sizes, depth, thickness, and texture are all possible. 
     Referring to  FIGS. 1, 2, and 8 , the drill safety system may include a vacuum unit  50 . As indicated above, the vacuum unit  50  is used to collect the shavings from the inner side  220 . The collecting cup  60  of the vacuum unit  50  has a lower cup body  62  and an enlarged cup rim  63 , wherein the cup rim  63  may fit on the inner surface  220 . The collecting cup  60  covers the drilling site  240 , providing a complete shielding and collecting structure that ensures all metal and non-metal shavings on the inner surfaces are properly gathered. Although the collecting cup  60  has a round opening, it should be noted that other shapes, such as square, may also be adopted. In a preferred embodiment, the inner surface  240  is a flat surface and the cup rim  63  may fit on the flat surface. 
     The collecting cup  60  and the connecting tube  80  are the essential elements of the vacuum unit  50 , which can be connected to a vacuum motor providing suction power, allowing shavings on the inner surface to be collected. The connecting tube  80  may be rigid or flexible. In addition, as indicated by  FIGS. 1 and 2 , the vacuum unit  50  may further include a first connector  70 , a second connector  75 , and a handle element  85 , which may include a handle tube  86  and a handle  87 , wherein the collecting cup  60 , the first connector  70 , the connecting tube  80 , the second connector  75 , and the handle tube  86  all hollow inside and are sequentially connected, forming a through channel. 
     Preferably, a user may take hold of the handle  87  and manually press the collecting cup  60  to the inner surface  240 . Such an embodiment does not require the worker to reach inside the housing of live switchgear and improves safety. Alternatively, the cup rim  63  may include magnets so that the collecting cup  60  can magnetically attach to the inner surface  240 , allowing the person conducting the drilling to do the work alone. The first connector  70  and the second connector  75  are structures that provide more flexibility to the design of the vacuum unit  50  and these structures may have different length and twisting angles. By adjusting the first connector  70  and the second connector  75 , as well as the connecting tube  80  and the handle element  85 , a user may reconfigure the vacuum unit  50  to avoid pressing the various parts of the vacuum unit  50  against the equipment in the workpiece. Various methods can be used to connect the collecting cup  60 , the first connector  70 , the connecting tube  80 , the second connector  75 , and the handle element  85 . These structures can be screwed, molded, welded, or glued together, or using any combination of suitable methods. 
     Referring to  FIGS. 3, 4, 5, and 8 , the magnetic unit  10  is used to collect the metal shavings on the drilling surface  210 . Before drilling, the magnetic unit  10  is placed on the drilling surface  210 , and around and/or adjacent to the drilling site  240 . Since the magnetic unit  10  includes magnets  30 , when the workpiece is metal, the magnetic unit  10  may securely attach to the workpiece without the aid of gravity. This feature is particularly useful when the drilling surface is not horizontal. In a preferred embodiment as shown in  FIGS. 3-5 , the magnetic unit has a ring or annulus shape, especially if viewing from the top. The ring shape allows the magnetic unit  10  to surround the drilling site  240 , as shown in  FIG. 8 . However, it should be noted that the shape of the magnetic unit  10  may vary according to the specific job to be conducted, the size and shape of the work piece, and surface conditions. For example, the magnetic unit  10  may be an elongated strip that may be flexed and twisted to conform to a specific drilling work. The strip-shaped magnetic unit  10  may even be twisted in a circle to mimic the ring-shape embodiment. 
     The cover  20  of the magnetic unit may comprise a unit base  24  and a flippable top  27 , wherein the magnet core—the magnets  30  combined with the connector  33 —may be placed on the unit base  24  and be shielded by the flippable top  27  when the flipped top  27  is flipped down. It is possible that the unit base  24  and the flippable top  27  form a single continuous structure. Alternatively, the unit base  24  and the flippable top  27  may be distinct but attached structures that as a whole form a cover  20  shielding the a magnet core. It should also be noted that while the embodiment shown in  FIGS. 3-5  show the flippable top  27  to expose the inner structures of the magnetic unit  10  by flipping up, other designs are still possible. The key feature for the cover  20  is that it may be opened so that the magnets may be removed. Specific designs may vary and as long as the general structures fit with the essential concept, such designs are incorporated in the current invention. 
     When the flippable top  27  is flipped down, no magnet is directly exposed. The metal shavings resulted from drilling on the drilling surface are pulled towards the magnetic unit  10  and attached to the cover  20 , which is preferably non-magnetic and non-conductive. After drilling, as shown in  FIGS. 4-5 , the flippable top  27  is flipped up, allowing the magnets  30  to be removed so that the metal shavings can no longer attach to the cover  20 . The user may then easily discard the shavings, put the magnets  30  back, flip down the flippable top  27 , and make the magnetic unit  10  ready to be used again. 
     To ensure the physical robustness of the magnetic unit  10 , a support structure  40  may be included to provide physical support to the magnetic unit  10 . The support structure  40  is preferred to be rigid and it may conform to the shape of the magnetic unit  10 . As indicated above, the shape of the magnetic unit  10  may vary. Therefore, the size and shape of the support structure  40  may vary accordingly. 
     The magnets  30  used in the current invention are preferably permanent magnets and may be any type of magnetic material, including but not limited to: metallic magnets, composite magnets, and rare earth magnets, and any combination thereof. The magnet connectors  33  are optional elements used to link two or more magnet pieces together, allowing easier placement and removal. A magnet  30  may have a wrap that covers the magnet  30 , wherein the wrap may directly link with the magnet connector  33 . It is preferred that the magnet connector  33  is flexible, allowing the magnet pieces to bend against one another. The embodiment shown in  FIG. 5  includes two magnets sets, each including two magnet pieces linked by a magnet connector  33 . It should be clear that such format may vary according to the size of the magnetic unit  10 , the magnetic power required, and the specific needs of the drilling work. 
     Referring to  FIGS. 6, 7, and 8 , the drill safety system may include an improved hole saw drill set  90  that includes a stopper flange  96 . As indicated above, similar to the conventional hole saw drill bit, the current hole saw  95  is a cylinder structure that can be connected, usually with a threaded section, to a drill arbor  94 , wherein the front end  97  of the cylinder facing the board  200  has sawteeth that may cut through the board  200  to produce a hole at drilling site  240 . In the current improved hole saw drill set  90 , the hole saw arbor  94  includes a stopper flange  96  extending from a periphery of the hole saw arbor  94  and positioned right behind and abutting the back end  98  of the hole saw  95 , blocking the advancement of the hole saw  95  when the entire cylinder of the hole saw  95  has cut into the workpiece. 
     The length  99  of the hole saw  95 , measured from the front end  97  to the back end  98 , sets a maximum limit for the depth of the hole. To cut a through hole on the board  200 , the thickness of the board  200  must be smaller than the length  99  of the hole saw  95 . Such a design prevents over-penetration, protects the inner structures of the workpiece, and in essence puts more emphasis on the safety of the device. It is a better design compared with placing the stopper flange directly on the back end  98  of the hole saw  95  because the current design allows hole saws with different lengths to be used with the same drill arbor  94 . The user may choose drill bits having different lengths for different projects and use the same drill arbor, ensuring that the drilling can be conducted effectively and protection is provided at the same time. 
     As indicated above, the various parts of the drill safety device may be used individually and in combination with one another. For example, the user may utilize a conventional hole saw drill bit for drilling that is protected by the magnetic unit  10  and the vacuum unit  50 . The magnetic unit  10  may be used together with traditional make-shift arrangement used by electricians or the device disclosed in U.S. Pat. No. 6,974,048. The magnetic unit  10  and the vacuum unit  50 , when used together, provide a complete solution for debris removal when drilling on metallic workpieces. The inclusion of the improve hole saw drill bit further adds to the level of security that prevents damages and accidents. 
     In terms of dimension, the sizes of various parts of the drill safety system may vary according to drill beings used, the intended drilling results, and the size and the shape of the workpiece. The collecting cup  60  is preferred to provide sufficient coverage of the drilling site  240 . The covered area of the collecting cup  60 , measure by the area within the cup rim  63 , is preferred to range from 1 cm 2  to 1 m 2 , with the more preferred range of 10 to 200 cm 2 . The overall length of the vacuum unit  50  may range from 10 cm to 5 m, with the preferred range of 30 to 100 cm. When the magnetic unit  10  has a ring shape, as indicated in  FIGS. 3-5 , the inner diameter may range from 1 cm to 1 m, with the preferred range of 5 to 30 cm, the outer diameter may range from 1 cm to 1.5 m, with the preferred range of 5 to 50 cm, and the ration of (outer diameter)/(inner diameter) may range from 1.1 to 5, with the preferred range of 1.2 to 2.5. The length  99  of the hole saw  95  may range from 0.5 to 100 cm, with the preferred range of 1 to 20 cm. 
     It is preferred that various parts of the drill safety system are not too heavy so that they may be held, transported, and used with easy. In particular, the vacuum unit  50  is preferred to be light because in some cases, a user is supposed to hold the vacuum unit  50  during drilling. The overall weight of the vacuum unit  50  may range from 10 g to 20 kg, with the preferred range of 100 g to 5 kg. The overall weight of the magnetic unit  10  may range from 50 g to 20 kg, with the preferred range of 200 g to 10 kg. The overall weight of the drill set  90  may range from 10 g to 5 kg, with the preferred range of 20 g to 2 kg. 
     In terms of materials, any part of the vacuum unit  50  and the magnetic unit  10  that make contact with the workpiece is preferred to be non-conductive and non-magnetic. The various parts of the vacuum unit  50  may be made from the same or different materials. The material is preferred to be safe, strong, and impermeable to liquid. Moreover, it would be desirable that the material is inexpensive and easy to process during manufacture. The materials that may be used include but are not limited to: rubber, and plastic such as, but not limited to, polyethylene terephthalate (PET), polyethylene (PE), high-density polyethylene, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), high impact polystyrene (HIPS) and polycarbonate (PC), or paperboard coated with a suitable coating such as, but not limited to, polyethylene, or some combination thereof. The various parts of the magnetic unit  10  may be made from the same or different materials. The magnets  30 , as indicated above, are preferred to be permanent magnets. The cover  20  of the magnetic unit  10  is preferred to be non-conductive, non-magnetic, flexible but durable so that the flippable top  27  may be flipped up and down numerous times. The materials suitable to make the cover  20  include but are not limited to rubber, and plastic such as, but not limited to, polyethylene terephthalate (PET), polyethylene (PE), polyvinylidene chloride (PVDC), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), high impact polystyrene (HIPS) and polycarbonate (PC), or paper or fabric coated with a suitable coating such as, but not limited to, polyethylene, or some combination thereof. The preferred material for the cover  20  of the magnetic unit  10  is rubber. 
     As indicated above, the primary focus of the current invention is to improve safety during the drilling of live equipment. However, the use of the current invention is much broader. For example, with proper arrangement, the vacuum unit, the magnetic unit, and the improved hole saw will also help to save time in new installations. When the workers are doing new installations of switch gear, holes are drilled into the housing. The conventional approach is to use some make-shift arrangement or vacuum out the equipment after drilling has been completed. In systems like data centers each piece of gear may have 8-16 conduits and a significant amount of shavings may be left on top of the gear. The electricians usually need to spend several days vacuuming out all of the gear before it can be energized for the first time. Using the current invention significantly lessens the time and man-power to clean the new gear before energizing it for the first time because the debris is collected while holes are being drilled. 
     In addition, the current invention may be used to install new circuits underneath raised computer floors sites such as data centers, which have very strict rules about debris caused by new installations in such critical environments. Air conditioning usually moves underneath the floor, creating a strong flow of air that may spread the shavings. This is a situation where the worker is either drilling from underneath equipment and debris would be falling into the clean computer floor or drilling into a junction box that is under the raised floor where the air flow is moving and blowing everything around. The conventional approach is to have a worker hold a shop vacuum nozzle next to the drill site while another worker drills. Then, the floors are vacuumed and coated after a new install before a company moves in. The conventional method gets most of the debris but usually misses whatever is on the side of the drill opposite the vacuum nozzle. Using the current invention properly collects all the shavings while drilling is being conducted, saving a significant amount of time and cost. 
     Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of illustration and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention.