Patent Publication Number: US-6701814-B2

Title: Multiblade screwdriver

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 09/608,156 filed Jun. 30, 2000, now U.S. Pat. No. 6,378,407 which is a continuation-in-part of U.S. application Ser. No. 09/209,766 filed Dec. 11, 1998 now abandoned. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to hand-held screwdrivers having interchangeable blades which are held within the handle and are available to be selected for various types of screws such as those having a straight slot, Phillips head, etc. Alternatively, the blades can be adapted to receive sockets or other shapes to hold or drive various types of fasteners. 
     DESCRIPTION OF RELATED ART 
     There are and have been on the market multiblade screwdrivers which are simply units with a hollow handle in which a number of screw driver blades are stored, and with a removable cap so that the blades can be removed and affixed to one end of the handle in operative position. These have the negative factor of loose blades which can be readily removed and misplaced. 
     Other forms of multiblade screw drivers are illustrated by U.S. Pat. Nos. 4,463,788; 4,716,796; 4,557,943 and 5,228,363. All of these have multiple, usually six, screwdriver blades or shafts which are mounted in multiple peripheral openings or storage slots disposed lengthwise on the outer portion of the handle. The operator can select the desired blade located in the storage portion of the handle and slide it forward toward an operative position. The blade moves forward through the storage slot to the forward end of the handle until it reaches a point where a stopping mechanism on the base of the blade engages the inside of the cap and prevents the blade from falling out. The blade is then in the outer portion of a cross slot in the cap perpendicular to and above the storage slot. It can be moved in the cross slot toward the center of the handle and when in the center, moved toward the back of the handle into a chuck element, generally having a magnet in its base, which holds the blade in operative position on the central axis of the screwdriver assembly. Shaped portions in the base of the blade engage correspondingly shaped portions of the chuck to prevent rotation of the blade when it is in the chuck. This permits a downward, twisting force to be exerted on the blade/handle combination to engage the fastener and prevent rotation of the blade in the handle to permit screwing or unscrewing of the fastener. 
     In the prior art devices, the cross slot through which the blade moves from storage to operative position in the chuck is composed of two parts, a slot in the top of the cap which encloses the forward end of the handle and a corresponding slotted portion in a rotatable disk which can rotate within the cap. When moving the blade from storage to operative position, the cross slots are lined up to permit the movement of the selected blade from the storage to the operative position or vice versa. To retain the blade in the chuck and prevent movement of the blade either outward or within the slot, the disk is rotated, perhaps 90 degrees, so that the disk having the slot no longer is lined up with the slot in the cap and thus the blade is held or locked in place in the chuck. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to prevent rotation of the cap assembly when the blade is in the chuck, thus precluding the introduction of a second blade into the cross-slot which can occur in prior art devices because a user&#39;s hands gripping the handle and twisting the screwdriver can fairly easily rotate and unlock the exposed lock ring on the disk mounted in the forward end of the handle. 
     It is a further object of the invention to construct a multiblade screwdriver with the use of fewer and simpler parts while providing the same ability to move from storage to operative position, to retain the blade within the handle and to move to the operative position, locking the blade into the operative position. 
     Applicant&#39;s improved construction provides for a blade of simple polygonal, and preferably hexagonal, cross sectional configuration, eliminating relatively expensive forming or machining steps required to make the blade configuration in the prior art devices. Thus, the blade configuration can be formed from a hexagonal length of steel of like metal having a screwdriver shape or configuration at the outer end. The portion near the inner end has a flat notch cut in opposite sides of the hex, preferably in angled portions. This notch is cut across the hex on two portions of the hex opposite each other to form a flat sided notch which will enable the blade to slide along a track portion of the opening which is formed in the cap. A lug or “wing” is formed on the inside base portion of the blade adjacent one or both of the flat notched portions for the purpose of engaging the inside of the cap adjacent to the hex opening track portions to prevent the blade from being removed from the handle. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a screwdriver assembly according to the invention with the blades retracted into the handle; 
     FIG. 2 is a perspective view of the screwdriver assembly of FIG. 1, with a blade extended into operative position; 
     FIG. 3 is a vertical cross-sectional view of the screwdriver assembly of FIG. 2; 
     FIG. 4 is a side view of one of the blades of the screwdriver assembly of the invention; 
     FIG. 5 is a side view of the blade of FIG. 4 rotated 90°; 
     FIG. 6 is an elevational view of a screwdriver handle of the invention with its cap removed; 
     FIG. 7 is a cross-sectional view taken substantially along line A—A of FIG. 6; 
     FIG. 8 is a cross-sectional view taken substantially along line B—B of FIG. 6; 
     FIG. 9 is an enlarged detail of a blade storage slot according to the invention; 
     FIG. 10 is an enlarged cross-sectional view of a screwdriver cap according to the invention; 
     FIG. 11 is a bottom view of the cap of FIG. 10; 
     FIG. 12 is an elevational view of the cap of FIG. 10; 
     FIG. 13 is a top perspective view of a retainer of the screwdriver assembly of the invention; 
     FIG. 14 is a bottom view of the retainer of FIG. 13; 
     FIG. 15 is a top view of an alternate embodiment of a blade of the invention; and 
     FIG. 16 is a cross-sectional view taken substantially along line A—A of the handle of FIG. 6, in an alternate embodiment used with the blade of FIG.  15 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The screwdriver assembly of the invention, as shown in FIGS. 1,  2  and  3  has a handle  9  and a plurality of interchangeable blades  10 . FIG. 1 shows the handle  9  with all blades retracted and in the storage position, while FIG. 2 shows the screwdriver assembly with a blade  10  in an operative position. FIG. 3 is a cross-section of the screwdriver assembly with one blade  10  in operative position extending through the cap and another slotted blade  10 ′ in a storage position. The blades  10  are formed from hexagonal steel segments shown in FIGS. 4 and 5, having flat surfaces  10   a  connected by angle portions  10   b , and having a flat screwdriver tip  11  formed at the forward end of the blade. In the preferred embodiment shown in FIGS. 4 and 5, two opposing notches near the back end of the blade are formed by cutting opposing angle portions  12  of the hex to form flat guide surfaces  13  in the hex; a projection-stop means  14  is formed rearward of and adjacent to one of the slots  13 . Cutting the notches in the angle portions of the blade enables a reduction in the diameter of the handle. The projection stop-means  14  is adapted to go through the blade slot openings  16  and  17  shown in FIGS. 7,  8  and  9 , and to engage the retainer/cap assembly at  28 , shown in FIG. 14, to prevent it from being withdrawn from the handle. 
     The handle  15  has a plurality of peripheral storage slots  16  to hold the hexagonal blades disposed around the periphery of the handle parallel to the central axis of the handle which includes a chuck  16   a  for receiving a blade in its operative position. The blade storage slot opening viewed from the upper end has a configuration  17  which holds in sliding engagement the hexagonal blades with a projection receiving slot  18  which receives and guides the projection-stop means  14  in the blade. The handle  15  in FIG. 6 has cap receiving tabs  19  which are adapted to hold a cap on the forward end of the handle. 
     FIG. 10 is a cross-section of a cap having an internal groove  20  which rotatably engages tabs  19  to enable the cap to rotate on the forward portion of the handle. FIG. 11 shows the inside of the cap, having a blade guiding opening including hex portion  21  which receives a blade from the storage position or returns it to the storage position. A hex portion  22  disposed in the center above the retainer disc  25  shown in FIG.  13  and an intermediate opening slot  23  which connects the two hex portions  21  and  22 . The width of the slot  23  corresponds to the distance between the two faces of flat slot  13  in FIG.  5 . 
     FIG. 12 is a side view of the cap showing an arrow which can be lined up with the blades in the storage position in the handle to move or return blades from the storage position to the chuck position. 
     FIGS. 13 and 14 show a retainer which includes a disk portion  25  and a depending blade guide portion  26  of which outside portions  27  engage stop projections  24  in the cap, as shown in FIG. 11, to prevent the disk portion which fits in the cap from rotating relative to the cap. 
     The blade guide portion  26  of the retainer guides the base of the blade being introduced to the chuck. When the blade is in an operative position in the chuck  16   a , the retainer/cap assembly is prevented from rotating because the hex blade portion which is in the hex shaped chuck can not rotate with respect to the handle and because the hex opening of the cap and the retainer are also hex shaped, thus preventing everything from rotating until the blade is withdrawn from the chuck when it is being returned to the storage position via hex portions  21  and  22 , and slot  23 , from a blade position in hex portion  22  to the storage position which would be lined up with hex portion  21 . 
     In the embodiment shown in FIGS. 15 and 16, a blade  30  is formed with notches  32  cut in flat portions  34 . While the operation of this screwdriver assembly is essentially the same as the operation of the previously described embodiment, a larger diameter handle is required for the same complement of blades, as can be seen in the arrangement of slots  38  in FIG.  16 .