Abstract:
A combination retractable saw and knife utility tool is disclosed that can be actuated and used by a person using only one hand. The tool has a lock to assure that an extended knife blade or saw blade will remain extended until the user of the tool releases the lock. A person may use one hand to hold, steady and manipulate a work piece that needs to be cut and/or sawed, while their other hand is used to hold and implement the combination knife and saw utility tool. The person may release the tool lock, retract one blade and extend another blade using only one hand.

Description:
FIELD OF THE INVENTION 
     The invention relates to a combination utility tool having both a retractable knife and saw blade that is used for cutting metal, wood, drywall, plaster and plastic. 
     BACKGROUND OF THE INVENTION 
     In the prior art there are a wide variety of tools that provide blades in which the blade is either folding or retractable. Some of these tools furnish a saw blade which is enclosed into a handle when not in use and extends out of the handle in a manner similar to a pocket knife when the tool is to be used as a saw. Some tools provide that the blade can be opened to several different positions. 
     Other tools that are commercially available provide blades that retract within a handle such as is found in utility knives. In these tools the blade retracts into a hollow portion of the handle when not in use and extends out of the handle when it is to be used as a knife. All of these tools are very handy for the worker. However, a worker who has need of a saw and a knife must typically carry two separate tools in their tool pouch. Carrying both of these tools along with assorted screwdrivers, hammers and other tools requires considerable room in a tool pouch and room in the tool pouch is limited. 
     Thus, there is a need for a compact, durable tool which can provide a worker with a combination utility tool which includes both a saw blade and a knife blade and enables the worker to saw or cut with the same tool. 
     U.S. Pat. No. 6,363,614 is one attempt at solving this need in the prior art. A knife blade and a saw blade are contained within a common handle of a tool. The knife blade is a standard utility knife blade, commonly available anywhere, used in prior art retractable blade utility knives. The knife blade extends longitudinally from the end of the tool handle alike other utility knives. The saw blade also extends longitudinally from the end of the tool handle. However, the saw blade is a custom blade that is not commonly obtainable anywhere. More importantly, the use of this tool requires the use of two hands. While the tool is held in one hand a lock and unlock cap 28 at one end of the tool must be turned counter-clockwise with the other hand to loosen blade 10 in order to either move the saw blade to an extended operable position or to retract it inside the tool handle. At either extreme the lock and unlock cap 28 must be turned clockwise with the other hand to lock the saw blade in that position. 
     U.S. Pat. No. 4,890,387 teaches a single tool having both a knife blade and a saw blade. The knife blade is a convention utility knife blade that extends longitudinally from one end of an elongated tool handle by manually sliding an actuator button on the side of the tool. This is a one hand operation. However, the use of the saw blade is a two hand operation. While the tool is being held in one hand a second hand must be used to pull the saw blade from within a slot in the side of the tool handle alike a folding pocket knife. The saw blade pivots out of the slot to be aligned with the elongated tool handle. There is no provision for replacing the saw blade. 
     U.S. Pat. No. 6,467,173 teaches a combination retractable saw and knife tool that is alike that taught in U.S. Pat. No. 6,363,614 and requires a two hand operation. While the tool is held in one hand a lock and unlock cap 28 at one end of the tool must be turned counter-clockwise with the other hand to loosen blade 10 in order to either move the saw blade to an extended operable position or to retract it inside the tool handle. At either extreme the lock and unlock cap 28 must be turned clockwise by the other hand to lock the saw blade in that position. 
     U.S. Pat. No. 5,023,996 teaches a combination retractable saw and knife device. This device also requires a two hand operation. There is a two part handle each comprising a saw blade housing and the two housings are pivotably connected at one end. A saw blade is mounted inside each housing and the blades are extended from the end of each housing/handle. Hacksaw blade 28 is deployed for use from inside its handle housing 48 by turning a knob 29 counter-clockwise to free the blade and extend it from its handle housing. Knob 29 is then used to lock blade 28 in its extended position. This two handed operation is repeated to retract hacksaw blade 28 inside its handle housing and lock it therein. A wood saw blade 31 is mounted inside the other handle housing 58 using a pair of spring loaded displaceable slides 34 and 35 having catches 36 and 37. The catches are received in notches 42 and 43 or 40 and 41 depending on whether blade 31 is extended from its handle housing or is retracted therein. Both of these blades require two hands to operate. For the hacksaw blade 28 the handle must be held with one hand while the other hand is use to turn knob 29, extract blade 28 and retighten knob 29. For the wood saw blade 31 the handle must be held with one hand while the other hand is used to squeeze catches 36 and 37 to release them from notches 42 and 43 and then to pull wood saw blade 31 from the handle. 
     A person who is working with or installing drywall/wallboard or other materials very often needs one hand to steady a piece of material to be cut while their other hand is used to cut the material. Therefore, a tool that requires two hands to operate is not practical. Thus, there is a continuing need for a new and improved combination drywall utility tool with knife and saw blades which addresses the unique problems associated with cutting and shaping drywall to be fastened to a support wall. More particularly, there is a need for a combination drywall knife and saw utility tool that can be actuated and used by a person using only one hand. The knife blade or saw blade can be easily extended, used, unlocked and retracted all using one hand. This leaves the person&#39;s other hand free to hold, steady and manipulate a piece of drywall while it is being cut. 
     Along and through one side of a prior art utility knife is a slot through which protrudes, and along which travels an actuator button. A person holding and using a prior art utility knife typically uses their thumb to first depress the actuator button and then move it along the slot through the side of the tool to expose the knife blade. When the actuator button is released the exposed knife blade is supposed to remain in its exposed position. However, too often during use the actuator button is inadvertently pressed and the knife blade retracts when the operator does not want it to. In addition, the actuator buttons have an integral spring that too often gets weak with use and being clogged up with material after continued use of the knife. When this happens the actuator button does not adequately perform its function of locking a knife blade in its extended position. Thus, there is also a need in art for a way to assure that an extended knife blade will remain locked in an extended position and will not inadvertently retract while in use. 
     SUMMARY OF THE INVENTION 
     The needs in the prior art for a combination utility tool having retractable knife and saw blades that can be actuated and used by a person using only one hand, and having a lock to assure that an extended knife blade or saw blade will remain extended until the user of the tool releases the lock, are satisfied by the present invention. A person may use one hand to hold, steady and manipulate a work piece that needs to be cut and/or sawed, while their other hand is used to hold and utilize the retractable combination knife and saw utility tool. 
     The utility tool is elongated and ergonomically shaped and is easily held in one hand. There is a slot through either end of the utility tool and a knife blade can protrude through the slot in one end of the utility tool while a saw blade can alternatively protrude out of the slot through the other end of the tool. Along and through a top side of the utility tool is a slot through which protrudes and along which travels an actuator button. This actuator button is alike those found on prior art utility knives, is spring loaded, and is used to manually extend either the knife blade or the saw blade through one end or the other of the utility tool. A person holding and using the utility tool typically uses their thumb to first depress the actuator button and then moves the button along the slot through the top side of the utility tool to expose the knife blade or the saw blade. When the actuator button is released the exposed knife blade or saw blade remains in its exposed position and is locked in that position. Thereafter, the actuator button alone cannot be used to withdraw the knife blade or saw blade. 
     When either the knife blade or the saw blade is extended through one end or the other of the utility tool the blade is held in held in its extended position by a locking mechanism. This prevents inadvertent retraction of either blade. The locking mechanism has small protrusions that extend through holes in the bottom side of the utility tool, opposite to the side through which the actuator button protrudes. There is one protruding locking mechanism for each of the two blades. The locking mechanism is shaped so that it cannot be inadvertently actuated to retract the knife blade or the saw blade. To retract the knife blade or the saw blade the locking mechanism is released and the actuator button is simultaneously used to retract an extended blade into the tool handle. The locking mechanism is released and the actuator button is depressed and moved along the slot through the side of the utility tool using only one hand, the hand that is holding the tool. When this is done the middle finger, ring finger and little finger are holding the tool while the forefinger releases the locking mechanism and the thumb depresses and slides the actuator button. 
     When it is desired to use the other blade within the handle of the tool, after an exposed blade is retracted, the user easily rotates the tool in their hand one-hundred eighty degrees, without the aid of their other hand, and uses their thumb to push the actuator button in the opposite direction to expose the other blade. 
     The knife blades used in the novel combination tool are trapezoidal shaped blades used in existing utility knives, and the saw blades used in the tool are readily available reciprocating power saw blades. This permits a wide range of saw blade types to be used, from a coarse blade to a fine metal cutting blade. In addition, the blades are available in all hardware stores. 
     The knife and saw blades are fastened to a carrier inside the utility tool. The carrier is moved by the actuator to extend and retract the blades. To change a knife and/or saw blade a finger operated screw on the side of the tool handle is first unscrewed by the tool user. Two handle sections of the tool then easily separate. The knife blade is easily removed and replaced in a manner known in the prior art. To remove and replace the saw blade a small saw blade retainer clip is first removed. The retainer has flexible tabs that lock the saw blade in position until the tabs retainer are depressed permitting the retainer to be removed. 
    
    
     
       DESCRIPTION OF THE DRAWING 
       The combination utility retractable saw and knife tool of the present invention will be better understood upon reading the following Detailed Description in conjunction with the drawings in which: 
         FIG. 1  shows a side view of the novel combination tool with both knife and saw blades retracted inside the handle; 
         FIG. 2  shows a top view of the novel combination tool with both knife and saw blades retracted inside the handle and showing the actuator button in its operating slot; 
         FIG. 3  shows a three dimensional view of the novel combination tool with the knife blade extended; 
         FIG. 4  shows a three dimensional view of the novel combination tool with the saw blade extended; 
         FIG. 5  shows a three dimensional exploded first view of the novel combination tool showing the parts from a first perspective; 
         FIG. 6  shows a three dimensional exploded second view of the novel combination tool showing the parts from a second perspective; 
         FIG. 7  is a blown up exploded view of a blade carrier with actuator button, knife blade, and the saw blade and its retainer which are inside the tool; 
         FIG. 8  is shown an assembled view of the blade carrier with actuator button, knife blade, and the saw blade and its retainer; 
         FIG. 9  is shown an enlarged first side view of the blade carrier with actuator button; 
         FIG. 10  is shown an enlarged second side view of the blade carrier with actuator button; 
         FIG. 11  is shown an enlarged view of a retainer that fastens the saw blade to the blade carrier; and 
         FIG. 12  is shown an enlarged top view of the blade carrier with actuator button; 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 1  is shown a side view of the novel combination utility tool  10  with both knife and saw blades retracted. Tool  10  has two side pieces  12  and  17 , of which only side  12  is seen in  FIG. 1 . Tool  10  is elongated and has ergonomically shaped grooves  42  in its bottom edge that match the positions of a person&#39;s fingers when they hold utility tool  10 . On top is seen actuator button  11  which is depressed and slid to the right to extend a knife blade as shown in  FIG. 3 , or is depressed and slid to the lift to extend a saw blade as shown  FIG. 4 . Actuator  11  is shown in its neutral position where neither the knife blade nor the saw blade is extended. 
     Also shown in  FIG. 1  is hand operated screw  13  which is used to open the two handle pieces  12  and  17  to replace the knife blade or saw blade as shown in other Figures. 
     On the bottom side of tool  10  are shown locking mechanisms  14  and  15 . Locking mechanism  14  is used to lock the knife blade in its extended position (see  FIG. 3 ) and must be depressed sideways (perpendicular to the page) while pushing downward on actuator  11  and sliding it to the left to detract the knife blade. Locking mechanism  15  is used to lock the saw blade in its extended position (see  FIG. 4 ) and must be depressed sideways (perpendicular to the page) while pushing downward on actuator  11  and sliding it to the right to detract the saw blade. 
     In  FIG. 2  is shown a top view of the novel utility tool  10  with both knife and saw blades retracted and showing the actuator button  11  in its neutral position. In this figure it can be seen that actuator button  11  slides along in a slot  18 . When button  11  is depressed and slid to the right the knife blade will be extended, and when depressed and slid to the left the saw blade will be extended. The two handle pieces  12  and  17  of utility tool  10  are seen in this top view. 
     In  FIG. 2  is also seen how the two handle pieces  12  and  17  of tool  10  disassemble to replace a knife or saw blade. Hand operated screw  13  is removed and the left end of the tool handle pieces are separated. A hooked protrusion  19  of handle piece  17  slides out of a mating depression in handle piece  12 . To reassemble the handle pieces these steps are reversed. 
     In  FIG. 3  is shown a three dimensional view of the novel utility tool with knife blade  20  extended. In this Figure it can be seen that actuator button  11  has been moved in the direction of arrow D 1 , from its neutral position as shown in  FIG. 2 , to the right hand end of slot  18 . Knife blade  20  is fully extended. To retract knife blade  20  locking mechanism  14  is pressed sideways by the user&#39;s forefinger while the user concurrently depresses actuator button  11  with their thumb and slides it to the left to its neutral position as shown in  FIGS. 1 and 2 . 
     In  FIG. 4  is shown a three dimensional view of the novel utility tool  10  with saw blade  21  extended. The drawing view shown in  FIG. 4  has been rotated one-hundred eighty degrees so that the saw blade is shown extending toward the viewer, rather than away from the viewer. This has been done to more clearly see saw blade  21  extending from the end of utility tool  10 . 
     In this Figure the two tool handles  12  and  17  are seen, as well as the hooked protrusion  19  on handle piece  17  and mating depression in handle piece  12 . As previously described, these are used in conjunction with hand operated screw  13  to disassemble and reassemble tool  10 . In  FIG. 4  only the threaded hole  22  through handle piece  17  is seen. The threaded portion of screw  13  lies in hole  22 , but otherwise screw  13  cannot be seen because it is on the backside of tool  10  in this Figure. 
     Actuator  11  has been moved along slot  18  from its neutral position (shown in  FIGS. 1 and 2 ) in the direction of arrow D 2  to fully extend saw blade  21 . Once fully extended locking mechanism  15  (not seen in this figure) locks saw blade  21  in its extended position until locking mechanism  15  is released and actuator  11  is concurrently, manually moved along slot  18  opposite to arrow D 2 . 
       FIG. 5  shows a three dimensional exploded first view of the novel utility tool  10  showing the parts from a first perspective, that is with saw blade  21  facing to the right. The opposite perspective exploded view is shown in  FIG. 6 . The two handle pieces are shown separated. Tool  10  is normally disassembled by unscrewing screw  13  from holes  22  and  23  and by unhooking hooked protrusion  19  from its mating slot  41 . 
     One view of the interior parts of utility tool  10  is generally shown in this  FIG. 5 . There is a lock piece  24  which is flat piece of spring steel that is slightly bowed as shown and has two holes through its middle. The holes are used to fasten lock piece  24  on the inside bottom of handle piece  17 . At the ends of lock piece  24  are two tabs  14  and  15 . The left most tab  14  is the knife locking mechanism  14  and the right most tab  15  is the saw locking mechanism  15 . When lock piece  24  is fastened to on the inside bottom of handle piece  17  locking mechanisms  14  and  15  do not lie against the inside of handle piece  17  but, rather, extend a small distance into the interior of assembled tool  10  where they interact with other parts of utility tool  10  to lock knife blade  20  or saw blade  21  in their extended positions. 
     Lock piece  24  with tabs  14  and  15  operate in the following manner to lock blade carrier  27  in one of its two extreme positions. Those positions are with knife blade  20  extended as shown in  FIG. 3  and with saw blade  21  extended as shown in  FIG. 4 . As described in the previous paragraph tabs  14  and  15  extend a small distance into the interior of assembled tool  10 . 
     When actuator button  11  is in its neutral position, as shown in  FIG. 2 , with neither blade  20  or  21  extended, blade retainer  29  is positioned internally midway between tabs  14  and  15 . As actuator button  11  is moved to extend knife blade  20 , tab  14  is depressed a little toward handle side piece  17  by the side of blade retainer  29 . When knife blade  20  is fully extended tab  14  travels beyond blade retainer  29  and resumes its undepressed position which is now behind blade carrier  29 . Thus, if an attempt is made to move actuator button  11  to retract knife blade  20 , blade carrier  29  is blocked and cannot move because of tab  14  being behind carrier  29 . To retract knife blade  20  tab  14  must be manually moved to the side toward handle side piece  17 . A person holding tool  10  does this using their forefinger. This moves tab  14  from behind blade carrier  29  and thereby frees it to move. At the same time the person uses their thumb to move actuator button  11  towards its neutral position. 
     Lock tab  15  operates in the same manner to lock saw blade  21  in its extended position. As actuator button  11  is moved to extend saw blade  21  tab  15  is depressed toward handle side piece  17  by the side of blade retainer  29 . With saw blade  21  is fully extended tab  15  moves behind blade retainer  29  and resumes its undepressed position which is now behind blade carrier  29 . Thus, if an attempt is made to move actuator button  11  to retract saw blade  21  blade carrier  29  is blocked and cannot move because of tab  15  being behind carrier  29 . To retract saw blade  21  tab  15  must manually been moved to the side, toward handle side piece  17 . A person holding tool  10  does this using their forefinger. This moves tab  15  from behind blade carrier  29  and thereby frees it to move. At the same time the person uses their thumb to move actuator button  11  towards its neutral position. 
     There is also a blade carrier  27  a part of which is spring loaded actuator button  11 . Trapezoidal shaped knife blade  20  mounts in a slot on one side of blade carrier  27  in a manner well known in the art. Saw blade  21  lies in a slot on the opposite side of blade carrier  27  and is locked therein using a saw blade retainer  29 . These parts are shown in and described in greater detail with reference to  FIGS. 7-12 . 
     An opposite view of the interior parts of utility tool  10  is shown in  FIG. 6 . This opposite view better shows how locking piece  24  is moved in the direction of arrow D 8  to be fastened into a fitted groove  28  on the inside bottom of handle piece  17 . Locking piece  24  may be fastened to handle piece  17  by screws and by other fastening means well known in the art. Hand operated locking screw  13  is moved in the direction of arrow D 7  and is inserted through hole  23  through handle piece  12  and its threaded shaft then turns into threaded hole  22  in handle piece  17 . When hooked protrusions  19  on the top and bottom of handle piece  17  are first inserted into their mating slots  41  in the top and bottom handle piece  12  and locking screw  13  is engaged, the handle pieces  12  and  17  are firmly fastened together. In  FIG. 6  the opposite side of blade carrier  27  is seen. 
     In  FIG. 7  is shown an enlarged, more detailed view of a blade carrier  27  with actuator button  11  attached thereto by a flat spring piece  32 , knife blade  20 , saw blade  21  and its saw blade retainer  29 . On assembly of a standard knife blade  20  to carrier  27  it is moved in the direction of arrow D 5  up against the far side of blade carrier  27 . Notches  37  on the top edge of knife blade  20  mate with raised portions on the far side of carrier  27  to hold trapezoidal shaped knife blade  20  in place when utility tool  10  is completely assembled. As is known in the art, if a portion of the knife edge of knife blade  20  becomes dull the knife blade may be turned over to use the opposite end of the knife edge. 
     To mount saw blade  21  to blade carrier  27  the base end of blade  21  with hole  30  there through is first slid in the direction of arrow D 4  into the slot in the side of blade carrier  27  formed by L shaped portions  33   a  and  33   b . The width of the slot is only slightly greater than the width of the base of saw blade  21 . The depth of the slot is only slightly wider than the combined thickness of saw blade  21  and retainer  29 . Hole  30  through the base of saw blade  21  is pushed down over cylindrical protrusion  31  formed in the side of blade carrier  27 . The diameter of protrusion  31  is only slightly smaller than the diameter of hole  30  to facilitate this. Finally, saw blade retainer  29  is moved in the direction of arrow D 3  and slides snugly into the same slot formed by L shaped portions  33   a  and  33   b . As retainer  29  is slid into the aforementioned slot the flexible tabs  35  of the retainer are momentarily deflected until they enter slots  48  and  49  (see  FIG. 10 ) to thereby prevent retainer  29  and saw blade  21  from inadvertently being removed from the slot and thereby from carrier  27 . Retainer  29  is locked in place and this prevents saw blade  21  from being removed from carrier  27  until retainer  29  is first manually removed. 
     In  FIG. 8  is shown an assembled view of blade carrier  27  with actuator button  11 , knife blade  20 , saw blade  21  and its retainer  29 . This figure better shows how the tabs  35  of saw blade retainer  29  fit within the upper and lower slots  48  and  49  (see  FIG. 10 ) formed by protrusions  36  which are part of blade carrier  27 . Saw blade retainer  29  is stamped from a flat piece of spring steel so tabs  35  may be flexed up and over protrusions  36  and into the slot formed by them as shown in  FIGS. 8 and 10 . In this position retainer  29  cannot be withdrawn from the groove formed by L shaped portions  33   a  and  33   b  in the side of blade carrier  27  until tabs  35  are manually raised from the slots  48  and  49  formed by protrusions  36 . This prevents saw blade  21  from inadvertently coming free from blade carrier  27 . The assembled blade carrier  27  is assembled between handle pieces  12  and  17  and slides longitudinally along a groove  42 ,  43  created by them. One portion  42  of the groove is seen on the inside of first handle piece  12  in  FIG. 5 , and the other portion  43  of the groove is seen on the inside of the other handle piece  17  in  FIG. 6 . When handle pieces  12  and  17  are assembled together the two grooves  42  and  43  form a channel inside utility tool  10  in which blade carrier  27  slides when actuator  11  is depressed and pressure is applied to actuator  11  to move it along slot  18  seen in  FIGS. 2 ,  3  and  4 . 
     In  FIG. 9  is an enlarged view of the side of blade carrier  27  on which knife blade  20  (not shown in this Figure) is mounted. There is a channel  47  on this side of carrier  27  formed by top raised edge  45  and bottom raised edge  46  which extend vertical to the page a distance equal to or slightly greater than the thickness of a knife blade  20 . The vertical distance between raised edges  45  and  46  is only slightly greater than the vertical height of a knife blade  20  which is placed in channel  47  on assembly of tool  10 . 
     There is also a raised edge  38  against which one of the sloped ends  51  of a trapezoidal shaped knife blade  20  rests when the blade is assembled to blade carrier  27 . To hold a knife blade  20  in place there is a bent over tab  39 . As shown in  FIG. 7  knife blade  20  has two notches  37  in its top edge. Tab  39  rests in one of the two notches  37  and, if blade  20  is reversed, rests in the other of the two notches  37 . When blade carrier  27  with a knife blade  20  is assembled inside the handles  12  and  17  of tool  10  blade  20  is held against carrier  27  and cannot move away from carrier  27  is a direction perpendicular to blade carrier  27  in  FIG. 9 . 
     In  FIG. 10  is an enlarged view of the side of blade carrier  27  to which saw blade  21  is attached. There is seen top L shaped piece  33   a  and bottom L shaped piece  33   b  that are better seen in  FIGS. 7 and 8 . L shaped pieces  33   a  and  33   b  form a slot into which the base of a saw blade  21  is slid in the direction of arrow D 4 . As previously described the thickness (depth into the page of  FIG. 10 ) of the slot is only slightly thicker than the combined thickness of saw blade  21  and saw blade retainer  29 . Circular hole  30  through the base of saw blade  21  (See  FIG. 8 ) is pushed down over cylindrical protrusion  31  on the side of saw blade carrier  27 . The diameter of protrusion  31  is only slightly smaller than the diameter of hole  30  to facilitate this. Finally, saw blade retainer  29  is moved in the direction of arrow D 3  and slides snugly into the same slot formed by L shaped portions  33   a  and  33   b  and is locked therein by its spring tabs  35  as seen in  FIG. 8 . The spring tabs  35  (not shown in  FIG. 10 ) rest in upper  48  and lower  49  slots formed by protrusions  36  which are part of blade carrier  27 .  FIGS. 7 and 8  show other details. 
     In  FIG. 11  is shown an enlarged view of saw blade retainer  29 . Retainer  29  is stamped out of a piece of spring type steel. Its has two tabs  35  that are connected to the main part of retainer  29  by a connecting piece  50  that can flex due to the material that the retainer is made of. As previously described, when saw blade retainer  29  is fully inserted into the slot described in the previous paragraph its tabs  35  flex upward and come to rest in the upper  48  and lower  49  slots formed by protrusions  36  as shown in  FIG. 8 . This locks saw blade  21  to blade carrier  27 . To remove saw blade  21  from blade carrier  27  the tabs  35  are manually flexed out of upper and lower slots  48 ,  49  and retainer  29  is manually slid in a direction opposite to arrow D 3  to remove it from the slot formed by L shaped portions  33   a  and  33   b  as shown in  FIGS. 7 and 8 . 
     In  FIG. 12  is shown a top view of blade carrier  27 . Actuator  11  is shown connected to retainer  27  by way of a flat spring  32 . As previously described tab  39  rests in one of the two notches  37  of knife blade  20  to hold it to blade carrier  27 . The top of L shaped portion  33   a  is seen. Upper protrusion  36  that forms upper slot  48  is also seen. Tabs  35  of saw blade retainer  29  lie in slots  48  and  49  to fasten saw blade  21  to blade carrier  27  as previously described. 
     While what has been described hereinabove is the preferred embodiment of the invention it will be apparent to those skilled in the art that numerous changes may be made without departing from the spirit and scope of the invention. The means by which the blade locks are implemented may be changed while still safely locking knife blades and saw blades in their extended positions. In addition, while tool  10  is disclosed with a knife blade and a saw blade other tool combinations may be implemented, such as two saw blades. In addition, the manner by which saw blades are fastened to the blade carrier may be varied.