CA2002162C - Screwdriver bit for phillips-head fasteners - Google Patents
Screwdriver bit for phillips-head fastenersInfo
- Publication number
- CA2002162C CA2002162C CA 2002162 CA2002162A CA2002162C CA 2002162 C CA2002162 C CA 2002162C CA 2002162 CA2002162 CA 2002162 CA 2002162 A CA2002162 A CA 2002162A CA 2002162 C CA2002162 C CA 2002162C
- Authority
- CA
- Canada
- Prior art keywords
- bit
- recess
- wings
- driver
- fastener
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
- B25B15/00—Screwdrivers
- B25B15/001—Screwdrivers characterised by material or shape of the tool bit
- B25B15/004—Screwdrivers characterised by material or shape of the tool bit characterised by cross-section
- B25B15/005—Screwdrivers characterised by material or shape of the tool bit characterised by cross-section with cross- or star-shaped cross-section
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
Abstract
A modified Phillips-type screwdriver bit is disclosed that is fully compatible with a standard Phillips-head fastener, and is designed to significantly increase the level of torque that can be applied to the fastener while at the same time substantially reducing the cam-out forces normally produced by a standard Phillips screwdriver bit. These results are accomplished by forming generated surfaces along the side walls of the bit wings so that the included angle defined by the converging side walls of adjoining bit wings gradually increases from the Phillips standard 92 degrees at the base of the bit wings to approximately 105 degrees at the wing tips. This configuration serves to confine the application of torque to the side surfaces of the bit wings initially along contact lines adjacent and parallel to the roots of the bit wings with the contact area gradually progressing radially outwardly as torque levels increase and the opposing side surfaces of the recess wings in the head of the fastener begin to deform.
Description
2~2~6~
IMPRaV~ SCREWDRIVER Brr FOR PHILLIPS-HE~D FASTENERS
Background and Summary of the Invention The present invention relates to screwdriver bits and in particular to an ill~LUV~d screwdriver bit for Ph;ll;ps-head fasteners that significantly reduces the "cam-out" experienced with a c~l.ven~ional screwdriver bit for Phillips-head fasteners.
C~l~v~-~ional Phillips-head fasteners and screwdrivers were originally developed to provide a fastening system that would facilitate efficient installation of fasteners on an assembly line.
In particular, as compared to conventional slotted screws, the ph; 11 ;ps screw was designed to center quickly and easily on the screwdriver and permit more torque to be applied to the screw so that it would hold tighter than conventional slotted æ rews. In addition, it was expressly contemplated that, when applied by auL~,~Led screwdrivers on an assembly line, the increasing torque applied to the Phillips screw would eventually cause the driver to pop out of the recess in the æ rew. In other words, the original Phillips-head design was intended to cause cam-out of the driver without damaging the screw head. It is, of course, this tendency of the Phillips-head design to cause cam-out of the driver, that is a principal source of irritation for craftsmen and ordinary consumers alike.
It is, therefore, the primary object of the present invention to provide an ill~Loved screwdriver bit that satisfies standard Phillips-head y~l~LL~ and, therefore, is useable with standard Phillips-head fasteners and yet is designed to significantly reduce the tendency of the driver to cam-out of the recess in the screw head.
2002~62 In addition, it is an object of the pLesenL invention to provide an ill~loved driver for Ph; 11 ip5-head screws that enables the application of significantly greater torque loads to a standard Ph;ll;ps-head screw with munimum distortion of the shape of the recess in the screw head.
Fur~henmnre, it is an object of the present invention to provide an il,~o-ved driver for Ph;ll;ps-head screws that enables the application of significantly greater torque loads to a standard Ph;ll;ps-head screw equally in both rotational directions.
Additional objects and advantages of the present invention will beoome apparent from a reading of the following detailed description of the preferred embcdiment which makes reference to the drawings in which:
Brief Description of the Drawings Figure 1 is a side elevational view of a standard screwdriver bit for Ph;ll;~s-head screws;
Figure 2 is an end view of the Ph;ll;ps bit shown in Figure l;
Figure 3 is a sectional view taken along line 3-3 in Figure 2;
Figure 4 is a partial sectional view taken along line 4-4 in Figure 3;
Figures 5 - 11 comprise a progressive series of sectional views of a standard Ph;ll;ps-type bit and screw fastening system starting from the base of the wings of the screwdriver bit in Figure 5 to the top of the head of the fastener in Figure 11;
6~
Figure 12 is a side elevational view partially in section of a standard Phillips fastening system;
Figure 13 is a force vector diagram illustrating the cam-out force o~.~unen~ generated by the standard Ph;llips fastener system;
Figure 14 is a sectional view of a standard Phillips fastener system illustrating the deformation of the recess in the head of the fastener;
Figure 15 is a enlarged view of one of the outer radial wing sections shown in Figure 14;
Figure 16 is a side elevational view of a Phillips-type screwdriver bit according to the present invention;
Figure 17 is a simplified perspective view of the bottom end of the bit shown in Figure 16;
Figures 18 - 24 comprise a progressive series of sectional views of the Phillips-type fastening system according to the present invention frcm the base of the wings of the screwdriver bit in Figure 18 to the top of the head of the fastener in Figure 24;
Figure 25 is an enlarged view of one of the wing sections of the Phillips-type fastening system according to the present invention;
Figure 26 is a sectional view similar to Figure 24 showing the screw~river bit applying maximum torque to the fastener;
Figure 27 is a side elevational view partially in section of the Ph;ll;ps-type fastening system according to the present invention;
Figure 28 is a force vector diagram illustrating the cam~out force cnmr~nP~t generated by the Ph;ll;ps-type fastener system according to the ~.es~,~ invention; and ;2Q~)%~6~
Figure 29 is an enlarged side elevational view partially in section of one of the wing sections of the Ph;llirs-type fastening system according to the present invention.
Detailed Description of the Preferred Embodiment The structure, significance, and advantages of the present invention are believed best understood if described in relation to a standard Phillips screwdriver bit. Acoordingly, Figure 1 in the drawings illustrates a standard No. 2 Phillips bit 10 and will be used as a starting point for the description of the present invention. A
standard Ph;ll;~s bit lO has a cross-shaped tip that is formed through the creation of four wedge.-shaped concave recesse.~ that converge toward the tip 11 of the bit. m e recesses define four evenly spaoe d wings 12 that are tapered along their outer radial surfaces 14 toward the tip of the bit. The angle of this taper is referred to as the "wing angle" and in a standard No. 1, 2, or 3 Phillips bit is equal to 26 degrees 30 minutes relati~e to the vertical axis of the bit. Ihe radially ;nnPrmnst part 16 of each recess is referred to as the "root"
16 and the angle at which the root diverges from the tip relative to the axis of the bit is referred to as the "root anglen. In a standard No. 2 Ph;ll;~s bit, the root angle of that portion of the bit 10 adapted to engage the fastener is 5 degrees 45 minutes, as shown in Figure 3. m e root angle in a standard No. 3 Ph;lll~s bit is also 5 degrees 45 minutes; however, the root angle is 7 degrees in a standard No. 1 Phillips bit. A~dition, as best illustrated in Figure 4, the angle formed by the adjoining interior wing surfaces 18, referred to as the "included angle", is 92 degrees in a standard No. 1, 2, or 3 Phillips bit and remains constant along the entire axial length of the bit wings 12. Finally, the tip 11 of a standard Phillips bit is con;~Ally shaped as shown in Figure 1 to form a point, the conical surface diverging from the point at an angle of 19 degrees relative to the plane normal to the axis of the bit. The specifications and dimensions for standard Ph;ll;~s-type bits are defined in literature published by the Screw Research Association.
Given the above ~ Lly for a standard Phillips bit 10, it is important to bear in mind, as shown in Figures 5 - 11, that the cross-shaped recess 20 formed in the head 22 of a standard Phillips-head fastener 24 is created with a punch having precisely the same dimensional characteristics. Accordingly, the standard Ph;ll;~s screwdriver bit 10 is adapted to fit precisely into the recess 20 formed in the head 22 of a standard Phillips fastener 24, except for a designed-in toleran oe clearance which enables the bit to fit readily into the recess 20. This relationship is clearly demonstrated in Figures 5 - 11 which comprise sectional views of a standard Phill;~s-type fastening system progressing in the axial direction from the base of the bit wings 12 in Figure 5 to the top of the head 22 of the fastener 24 in Figure 11.
In view of the precise conformity between the driver lO and the recess 20 in the head 22 of the fastener in a standard Phi 11 ;ps-type fastening system, it will be appreciated that as the screwdriver bit 10 is rotated in the clockwise direction, torque is applied to the head 22 of the fastener 24 along the outer radial edges 18 of the bit wings 12, as indicated by the arrows appearing in Figures 5 - 11. miS occurs due to the simple geametric fact that the ~Q02~62 points far~hest from the center of rotation move the greatest distance. Therefore, assuming a substantially unifonm tolerance gap between the bit 10 and the recess 20, the outer radial edges 18 of the bit wings 12 will take up the tolerance gap first and engage the opposing outer recess wing surfaces, establi~h;nq lines of contact therealong. The con~ LLcLion of torque along the outer radial edges 18 of the bit wings 12 results in the recess wings 21 in the head 22 of the fastener 24 defonming in these areas as torque levels increase.
This deformation is illusLL~ed in scmewhat exaga~erated form in Figures 14 and 15. Once this deformation occurs, the radially outward facing end surfaces 14 of the bit wings 12 came into contact with the newly formed opposing surfaces 26 in the deformation areas, thereby generating a significant force in the vertical direction (i.e., out of the paper relative to Figures 14 and 15) causing the driver 10 to "cam out" of the screw-head recess 20.
This phenamenon is illustrated and the related force vectors dia~r~l~d in Figures 12 and 13. In particular, as the torque applied along the outer radial edges 18 (Figure 11) of the bit wings 12 increases and deformation of the outer radial areas of the recess wings 21 occur, a force is generated by the radially outward facing end surfaces 14 of the bit wings 12 against the deformed surfaces 26 of the recess wings 21 in a direction normal to the end surfaces 14, as indicated by the arrows 27 in Figure 12. This, in turn, creates an equal and opposite force from the deformed surfaces 26 against the radially outward facing wing surfaces 14. This opposing force, designated "Z~l in the force diagram illusLLaLed in Figure 13 is comprised of a horizontal for oe r~ n~nL, designated "X", and a vertical force component, designated "Y". Given the Phillips-stan~Ard wing angle of 26 degrees 30 minutQs, the resulting cam-out force, "y-l, generated by the application of torque ~rom the screwdriver blt lO to the fastener 24 is equal to a factor of 0.43 (i.e., sin 26-30') times the magnitude of the force vector "~-. In other words, the greater the application of torque, the greater the force t~nd1~g to cam the screwdriver bit lO
out of the recess 20 in the head 22 of the fastener 24.
To obviate this cam-out tendency of the stAn~rd Phillips fasten~g system, the improved Phillips-type screwdriver bit according to the present invention has been designed so that torque loading between the bit and the recess in the head of a standard Phillips fastener is confined to the side faces of the bit wings. This is accomplished in the manner described below. Referring now to Figures 16 and 17, an improved Phillips-type screwdriver bit 30 according to the present invention is shown. At the outset it should be noted that the present screwdriver bit 30 retains the same root angle (either 5 degrees 45 minutes for a no. 2 or No.3 Phillips fastener, or 7 degrees for a No. l Phillips fastener) and eubstantially the same wing angle of 26 degrees 30 minutes according to standard Phillips specifications to ensure that the present bit 30 is fully compatible with standard Phillips-head fastenere. However, as will become apparent to those skilled in the art, to ensure compatibility with etandard Phillips fasteners, it is only necees~ry that the screwdriver bit according to the present invention possesses a root angle and wing angle approximately equal to but not substantially greater than (within limits) the standard Phillips dimensions. Thus, it will be appreciated that the present invention does not reguire a uniquely configured fastener to achieve its increased torque loading capabilities. Moreover, due to the radial symmetry of the present ecrewdriver bit 30, the increased 2do2l62 torgue loading capabilities of the present invention apply equally in both rotational directions of the driver.
Returning to the drawings, it will be noted from an examination of Figure 16 that the width of the radially outward facing surface 34 of the bit wing 32 remains substantially constant from the base 31 of the wing to the wing tip 35. This is contrary to the configuration of a standard Phillips bit, as illustrated in Figure 1, whose corresponding surface 14 gradually increases in width from the base 11 of the wing 12 to the wing tip 15 due to the geometry of the Phillips-stAn~rd root angle and the constant Phillips-stAn~Ard included angle. Specifically, the improved Phillips-type bit 30 according to the present invention does not maintain a constant included angle from the base 31 of the wing 32 to the wing tip 35,.
Rather, as illustrated in Figure 17, the included angle between the bit wings 32 in the present screwdriver bit 30 is equal to the Phillips-standard 92 degrees at the base 31 of the bit wings 32 and progressively increases to approximately 105 degrees at the wing tips 35. In other words, rather than the side surfaces of the bit wings 12 being defined by flat planes as in the ~tAndArd Phillips bit 10, the side surfaces of the bit wings 32 in the present bit 30 comprise generated surfaces. Therefore, as used herein and in the claims, the term "generated surface" refers to the non-planar, curved surface characteristic of the bit wing sidewalls that results from the varying included angle between ad; oining bit wings 32. This is demonstrated in FIG. 17. In the embodiment illustrated in FIG. 17 the included angle between the bit wings 32 is equal to the Phillips-stAn~Ard 92 degrees at the base 31 of the bit wings and p~oy~essively increases to approximately 105 degrees at the wing tipg 35. As a result, when the screwdriver bit 30 according to the present invention is inserted into the recess 20 of a standard Phillips-head fastener 24, a gradually increasing 20d2l62 -gap 38 (Figure 25) is defined between the blt wlngs 32 and the recess wings 21 in the radially outward direction.
This is due to the fact that the thic~ne~ of the recess wings 21 in the stAn~rd Phillips-head f~stener 24 diminishes more gradually in the radially outward direction due to the constant Phillips-stAnAArd included angle, which becomes progressively smaller than the increasing included angle of the present bit 30. In other words, the gap 38 ehown in Figures 24 and 25 results from the fact that the included angle between the sidewalls of the recess wings 21 corresponds to the Phillips-stAn~rd 92 degrees whereas the included angle between the bit wings 32 at this illustrated axial position of bit 30 co~Le~onds to approximately 103 degrees. (Note that the 103-degree angle referred to corresponds to the included angle at an axial position somewhat below the wing tip 35 as the entire bit portion typically does not fit into the recess 20 in the head of the fastener 24, as shown in Figure 27.) In addition, it is important to note that the radial dimension of the bit wings 32 when the bit is fully inserted into the recess 20 is less than that of the recess wings 21 so that a slight space is maintained between the radially outward facing surfaces 34 of the bit wings 32 and the opposing surfaces 44 of the recess wings 21. In the preferred embodiment of the present invention, the roots 36 of the recesses between adjoining bit wings 32 are also formed somewhat ~eerer so that an additional gap 40 (Figure 25) is created between the root 36 of the bit 30 and the root 42 of the recess 20 in the standard Phillips-head fastener 24. It has been earlier noted that the radially outwardly facing surfaces 34 of bit wings 32 taper toward a common point. It is further noted here that the thickness of the bit wings 32 adjacent the roots of these wings increases gradually in the axial direction away from this common point. This relationship follows from the fact that the root angle of the bit 30 ~s - ' 2bo2l62 compatible with the Phillips-~tandard root angle.
Finally, as illustrated in Figures 16 and 27, the base 31 of the present screwdriver bit 30 i8 preferably truncated as shown to prevent the bit 30 from bottoming out when in~erted into the recess 20 of a st~n~rd Phillips-head fastener 24.
As a result of this configuration, when the present screwdriver bit 30 is inserted into the recess 20 of a stAn~Ard Phillips-head fastener 24 and rotated in a clockwise direction, torque is applied to the fastener 24 along lines of contact 46 between the side surfaces of the bit wings 32 and the opposing side surfaces of - 9a-2C~0~1~Z
the recess wings 20, as indicated by the arrows appearing in Figures 18 - 24. In addition, it will be appreciated that these initial lines of contact 46 between the side surfaces of the bit wings 32 and recess wings 20 are essentially parallel to the root 36 of the bit 30, as illustrated by the dashed lines in ~igure 27. In other words, these lines of contact 46 form substantially the same 5-degree 45iminute angle with respect to the axis of the bit 30 corresponding to the Ph;ll;rs-standard root angle. Moreover, as the level of applied torque increases and the bit 30 begins to deform the recess 20, the lines of contact expand radially outwardly in parallel fashion along the side faces of the bit wings 32, as indicated by the shaded portion 50 illustrated in Figure 29. m is serves to significantly increase the level of torque that can be transmitted from the screwdriver bit 30 to the fastener 24 while confining the areas of engagement to the side surfaces of the bit wings 12. This distinction between the present invention and the standard Phillips bit is illustrated in Fig~lres 14 and 26.
Significantly, the deformation of the recess 20, as illustrated in Figure 26, along the sidcwPll~ of the recess wings 21 d oe s not add to the relatively small cam-out forces generated by the application of torque along the initial lines of contact 46 between the bit 30 and recess 20. Accordingly, driving eny~ nL between the screwdriver bit 30 and the fastener 24 can easily be maintained with the application of a modest amount of downforce. m is ph~ l of the present invention is illustrated and diay~ d in Figures 27 and 28. As previously noted, the application of torque from the bit 30 to the fastener 24 along the initial lines of contact 46 on the side ~00~62 surfaces of the bit wings 32 is represented by the dotted lines in Figure 27. m e ap~lic~tion of force in this manner results in the generation of an outwardly directed force c~l~onenL perpendicular to the lines of contact, as indicated by the arrows 45 in Figure 27.
m is, in turn, results in the generation of an equal and opposite force vector designated "Z" in the ~ccnmr~ying vector force diagram shown in Figure 28. In view of the a~lo~imated 5-degree 45iminute angle of the for oe ~Lol "Z" relative to the axis of the bit 30, the for oe vector "Z" is oamprised ~led~,linantly of a horizontal force component, l~hple~ "X", and a relative small vertical force component, labeled "Y". In fact, the vertical force cYxnponent "Y" tending to cause the bit 30 to cam-out of the re oe ss 20 is only equal to approximately a factor of 0.10 (i.e., sin 5 45') times the magnitude of the force vector "Z". Accordingly, when compared to a standard Ph;]l;ps bit 10, significantly less downward force is required from the O~e~a~Or to retain the present bit 30 in the recess 20 of a standard Phillips-head fastener 24, even at high levels of applied torque.
From the above discussion, it will be appreciated that the screw~river bit 30 according to the present invention is able to significantly reduce the cam-out for oe associa~ with a standard Ph;ll;ps screwdriver bit 10 by ~ ~.Ling the radially outward facing bit wing surfaces 34 from contacting the re oe ss 20 in the head 22 of the fastener 24. Due to the angle of these bit wing surfaces 34, the application of foroe along these surfa oe s is believed to be the greatest cause of cam-out in a standard Phillips design. m erefore, the present screwdriver bit 30 is capable of deforming the recess 20~ Z
wings 21 in a Phillips-head fastener 24 to the degree illustrated in Figure 26 before significant cam,out forces will be ~neLa~ed. At the stage illustrated in Figure 26, torque is being applied along virtually the entire side surfaces of the bit wings 32 from the initial lines of contact 46 adjacent the root 36 of the bit to the outer radial edges 48 of the bit wings 32.
Finally, it will be appreciated that, in view of the radially symmetrical design of the invention, the present screwdriver bit 30 is capable of applying significantly greater torque loads than a stan~rd Phillips bit in either r~tational direction. m erefore, unlike certain existing modified Phillips designs which radially offset the bit winas and are, therefore, primarily useable in only one rotational direction, the present invention is equally useful for tightly setting standard Philips screws and for "breaking free" and removing "frozen" Phillips fasteners.
While the above description constitutes the preferred ~mha~;m~nt of the invention, it will be appreciated that the invention is susceptible to dification, variation, and change without departing from the proper scope or fair mPAn;ng of the Acc~mpAnying claims.
IMPRaV~ SCREWDRIVER Brr FOR PHILLIPS-HE~D FASTENERS
Background and Summary of the Invention The present invention relates to screwdriver bits and in particular to an ill~LUV~d screwdriver bit for Ph;ll;ps-head fasteners that significantly reduces the "cam-out" experienced with a c~l.ven~ional screwdriver bit for Phillips-head fasteners.
C~l~v~-~ional Phillips-head fasteners and screwdrivers were originally developed to provide a fastening system that would facilitate efficient installation of fasteners on an assembly line.
In particular, as compared to conventional slotted screws, the ph; 11 ;ps screw was designed to center quickly and easily on the screwdriver and permit more torque to be applied to the screw so that it would hold tighter than conventional slotted æ rews. In addition, it was expressly contemplated that, when applied by auL~,~Led screwdrivers on an assembly line, the increasing torque applied to the Phillips screw would eventually cause the driver to pop out of the recess in the æ rew. In other words, the original Phillips-head design was intended to cause cam-out of the driver without damaging the screw head. It is, of course, this tendency of the Phillips-head design to cause cam-out of the driver, that is a principal source of irritation for craftsmen and ordinary consumers alike.
It is, therefore, the primary object of the present invention to provide an ill~Loved screwdriver bit that satisfies standard Phillips-head y~l~LL~ and, therefore, is useable with standard Phillips-head fasteners and yet is designed to significantly reduce the tendency of the driver to cam-out of the recess in the screw head.
2002~62 In addition, it is an object of the pLesenL invention to provide an ill~loved driver for Ph; 11 ip5-head screws that enables the application of significantly greater torque loads to a standard Ph;ll;ps-head screw with munimum distortion of the shape of the recess in the screw head.
Fur~henmnre, it is an object of the present invention to provide an il,~o-ved driver for Ph;ll;ps-head screws that enables the application of significantly greater torque loads to a standard Ph;ll;ps-head screw equally in both rotational directions.
Additional objects and advantages of the present invention will beoome apparent from a reading of the following detailed description of the preferred embcdiment which makes reference to the drawings in which:
Brief Description of the Drawings Figure 1 is a side elevational view of a standard screwdriver bit for Ph;ll;~s-head screws;
Figure 2 is an end view of the Ph;ll;ps bit shown in Figure l;
Figure 3 is a sectional view taken along line 3-3 in Figure 2;
Figure 4 is a partial sectional view taken along line 4-4 in Figure 3;
Figures 5 - 11 comprise a progressive series of sectional views of a standard Ph;ll;ps-type bit and screw fastening system starting from the base of the wings of the screwdriver bit in Figure 5 to the top of the head of the fastener in Figure 11;
6~
Figure 12 is a side elevational view partially in section of a standard Phillips fastening system;
Figure 13 is a force vector diagram illustrating the cam-out force o~.~unen~ generated by the standard Ph;llips fastener system;
Figure 14 is a sectional view of a standard Phillips fastener system illustrating the deformation of the recess in the head of the fastener;
Figure 15 is a enlarged view of one of the outer radial wing sections shown in Figure 14;
Figure 16 is a side elevational view of a Phillips-type screwdriver bit according to the present invention;
Figure 17 is a simplified perspective view of the bottom end of the bit shown in Figure 16;
Figures 18 - 24 comprise a progressive series of sectional views of the Phillips-type fastening system according to the present invention frcm the base of the wings of the screwdriver bit in Figure 18 to the top of the head of the fastener in Figure 24;
Figure 25 is an enlarged view of one of the wing sections of the Phillips-type fastening system according to the present invention;
Figure 26 is a sectional view similar to Figure 24 showing the screw~river bit applying maximum torque to the fastener;
Figure 27 is a side elevational view partially in section of the Ph;ll;ps-type fastening system according to the present invention;
Figure 28 is a force vector diagram illustrating the cam~out force cnmr~nP~t generated by the Ph;ll;ps-type fastener system according to the ~.es~,~ invention; and ;2Q~)%~6~
Figure 29 is an enlarged side elevational view partially in section of one of the wing sections of the Ph;llirs-type fastening system according to the present invention.
Detailed Description of the Preferred Embodiment The structure, significance, and advantages of the present invention are believed best understood if described in relation to a standard Phillips screwdriver bit. Acoordingly, Figure 1 in the drawings illustrates a standard No. 2 Phillips bit 10 and will be used as a starting point for the description of the present invention. A
standard Ph;ll;~s bit lO has a cross-shaped tip that is formed through the creation of four wedge.-shaped concave recesse.~ that converge toward the tip 11 of the bit. m e recesses define four evenly spaoe d wings 12 that are tapered along their outer radial surfaces 14 toward the tip of the bit. The angle of this taper is referred to as the "wing angle" and in a standard No. 1, 2, or 3 Phillips bit is equal to 26 degrees 30 minutes relati~e to the vertical axis of the bit. Ihe radially ;nnPrmnst part 16 of each recess is referred to as the "root"
16 and the angle at which the root diverges from the tip relative to the axis of the bit is referred to as the "root anglen. In a standard No. 2 Ph;ll;~s bit, the root angle of that portion of the bit 10 adapted to engage the fastener is 5 degrees 45 minutes, as shown in Figure 3. m e root angle in a standard No. 3 Ph;lll~s bit is also 5 degrees 45 minutes; however, the root angle is 7 degrees in a standard No. 1 Phillips bit. A~dition, as best illustrated in Figure 4, the angle formed by the adjoining interior wing surfaces 18, referred to as the "included angle", is 92 degrees in a standard No. 1, 2, or 3 Phillips bit and remains constant along the entire axial length of the bit wings 12. Finally, the tip 11 of a standard Phillips bit is con;~Ally shaped as shown in Figure 1 to form a point, the conical surface diverging from the point at an angle of 19 degrees relative to the plane normal to the axis of the bit. The specifications and dimensions for standard Ph;ll;~s-type bits are defined in literature published by the Screw Research Association.
Given the above ~ Lly for a standard Phillips bit 10, it is important to bear in mind, as shown in Figures 5 - 11, that the cross-shaped recess 20 formed in the head 22 of a standard Phillips-head fastener 24 is created with a punch having precisely the same dimensional characteristics. Accordingly, the standard Ph;ll;~s screwdriver bit 10 is adapted to fit precisely into the recess 20 formed in the head 22 of a standard Phillips fastener 24, except for a designed-in toleran oe clearance which enables the bit to fit readily into the recess 20. This relationship is clearly demonstrated in Figures 5 - 11 which comprise sectional views of a standard Phill;~s-type fastening system progressing in the axial direction from the base of the bit wings 12 in Figure 5 to the top of the head 22 of the fastener 24 in Figure 11.
In view of the precise conformity between the driver lO and the recess 20 in the head 22 of the fastener in a standard Phi 11 ;ps-type fastening system, it will be appreciated that as the screwdriver bit 10 is rotated in the clockwise direction, torque is applied to the head 22 of the fastener 24 along the outer radial edges 18 of the bit wings 12, as indicated by the arrows appearing in Figures 5 - 11. miS occurs due to the simple geametric fact that the ~Q02~62 points far~hest from the center of rotation move the greatest distance. Therefore, assuming a substantially unifonm tolerance gap between the bit 10 and the recess 20, the outer radial edges 18 of the bit wings 12 will take up the tolerance gap first and engage the opposing outer recess wing surfaces, establi~h;nq lines of contact therealong. The con~ LLcLion of torque along the outer radial edges 18 of the bit wings 12 results in the recess wings 21 in the head 22 of the fastener 24 defonming in these areas as torque levels increase.
This deformation is illusLL~ed in scmewhat exaga~erated form in Figures 14 and 15. Once this deformation occurs, the radially outward facing end surfaces 14 of the bit wings 12 came into contact with the newly formed opposing surfaces 26 in the deformation areas, thereby generating a significant force in the vertical direction (i.e., out of the paper relative to Figures 14 and 15) causing the driver 10 to "cam out" of the screw-head recess 20.
This phenamenon is illustrated and the related force vectors dia~r~l~d in Figures 12 and 13. In particular, as the torque applied along the outer radial edges 18 (Figure 11) of the bit wings 12 increases and deformation of the outer radial areas of the recess wings 21 occur, a force is generated by the radially outward facing end surfaces 14 of the bit wings 12 against the deformed surfaces 26 of the recess wings 21 in a direction normal to the end surfaces 14, as indicated by the arrows 27 in Figure 12. This, in turn, creates an equal and opposite force from the deformed surfaces 26 against the radially outward facing wing surfaces 14. This opposing force, designated "Z~l in the force diagram illusLLaLed in Figure 13 is comprised of a horizontal for oe r~ n~nL, designated "X", and a vertical force component, designated "Y". Given the Phillips-stan~Ard wing angle of 26 degrees 30 minutQs, the resulting cam-out force, "y-l, generated by the application of torque ~rom the screwdriver blt lO to the fastener 24 is equal to a factor of 0.43 (i.e., sin 26-30') times the magnitude of the force vector "~-. In other words, the greater the application of torque, the greater the force t~nd1~g to cam the screwdriver bit lO
out of the recess 20 in the head 22 of the fastener 24.
To obviate this cam-out tendency of the stAn~rd Phillips fasten~g system, the improved Phillips-type screwdriver bit according to the present invention has been designed so that torque loading between the bit and the recess in the head of a standard Phillips fastener is confined to the side faces of the bit wings. This is accomplished in the manner described below. Referring now to Figures 16 and 17, an improved Phillips-type screwdriver bit 30 according to the present invention is shown. At the outset it should be noted that the present screwdriver bit 30 retains the same root angle (either 5 degrees 45 minutes for a no. 2 or No.3 Phillips fastener, or 7 degrees for a No. l Phillips fastener) and eubstantially the same wing angle of 26 degrees 30 minutes according to standard Phillips specifications to ensure that the present bit 30 is fully compatible with standard Phillips-head fastenere. However, as will become apparent to those skilled in the art, to ensure compatibility with etandard Phillips fasteners, it is only necees~ry that the screwdriver bit according to the present invention possesses a root angle and wing angle approximately equal to but not substantially greater than (within limits) the standard Phillips dimensions. Thus, it will be appreciated that the present invention does not reguire a uniquely configured fastener to achieve its increased torque loading capabilities. Moreover, due to the radial symmetry of the present ecrewdriver bit 30, the increased 2do2l62 torgue loading capabilities of the present invention apply equally in both rotational directions of the driver.
Returning to the drawings, it will be noted from an examination of Figure 16 that the width of the radially outward facing surface 34 of the bit wing 32 remains substantially constant from the base 31 of the wing to the wing tip 35. This is contrary to the configuration of a standard Phillips bit, as illustrated in Figure 1, whose corresponding surface 14 gradually increases in width from the base 11 of the wing 12 to the wing tip 15 due to the geometry of the Phillips-stAn~rd root angle and the constant Phillips-stAn~Ard included angle. Specifically, the improved Phillips-type bit 30 according to the present invention does not maintain a constant included angle from the base 31 of the wing 32 to the wing tip 35,.
Rather, as illustrated in Figure 17, the included angle between the bit wings 32 in the present screwdriver bit 30 is equal to the Phillips-standard 92 degrees at the base 31 of the bit wings 32 and progressively increases to approximately 105 degrees at the wing tips 35. In other words, rather than the side surfaces of the bit wings 12 being defined by flat planes as in the ~tAndArd Phillips bit 10, the side surfaces of the bit wings 32 in the present bit 30 comprise generated surfaces. Therefore, as used herein and in the claims, the term "generated surface" refers to the non-planar, curved surface characteristic of the bit wing sidewalls that results from the varying included angle between ad; oining bit wings 32. This is demonstrated in FIG. 17. In the embodiment illustrated in FIG. 17 the included angle between the bit wings 32 is equal to the Phillips-stAn~Ard 92 degrees at the base 31 of the bit wings and p~oy~essively increases to approximately 105 degrees at the wing tipg 35. As a result, when the screwdriver bit 30 according to the present invention is inserted into the recess 20 of a standard Phillips-head fastener 24, a gradually increasing 20d2l62 -gap 38 (Figure 25) is defined between the blt wlngs 32 and the recess wings 21 in the radially outward direction.
This is due to the fact that the thic~ne~ of the recess wings 21 in the stAn~rd Phillips-head f~stener 24 diminishes more gradually in the radially outward direction due to the constant Phillips-stAnAArd included angle, which becomes progressively smaller than the increasing included angle of the present bit 30. In other words, the gap 38 ehown in Figures 24 and 25 results from the fact that the included angle between the sidewalls of the recess wings 21 corresponds to the Phillips-stAn~rd 92 degrees whereas the included angle between the bit wings 32 at this illustrated axial position of bit 30 co~Le~onds to approximately 103 degrees. (Note that the 103-degree angle referred to corresponds to the included angle at an axial position somewhat below the wing tip 35 as the entire bit portion typically does not fit into the recess 20 in the head of the fastener 24, as shown in Figure 27.) In addition, it is important to note that the radial dimension of the bit wings 32 when the bit is fully inserted into the recess 20 is less than that of the recess wings 21 so that a slight space is maintained between the radially outward facing surfaces 34 of the bit wings 32 and the opposing surfaces 44 of the recess wings 21. In the preferred embodiment of the present invention, the roots 36 of the recesses between adjoining bit wings 32 are also formed somewhat ~eerer so that an additional gap 40 (Figure 25) is created between the root 36 of the bit 30 and the root 42 of the recess 20 in the standard Phillips-head fastener 24. It has been earlier noted that the radially outwardly facing surfaces 34 of bit wings 32 taper toward a common point. It is further noted here that the thickness of the bit wings 32 adjacent the roots of these wings increases gradually in the axial direction away from this common point. This relationship follows from the fact that the root angle of the bit 30 ~s - ' 2bo2l62 compatible with the Phillips-~tandard root angle.
Finally, as illustrated in Figures 16 and 27, the base 31 of the present screwdriver bit 30 i8 preferably truncated as shown to prevent the bit 30 from bottoming out when in~erted into the recess 20 of a st~n~rd Phillips-head fastener 24.
As a result of this configuration, when the present screwdriver bit 30 is inserted into the recess 20 of a stAn~Ard Phillips-head fastener 24 and rotated in a clockwise direction, torque is applied to the fastener 24 along lines of contact 46 between the side surfaces of the bit wings 32 and the opposing side surfaces of - 9a-2C~0~1~Z
the recess wings 20, as indicated by the arrows appearing in Figures 18 - 24. In addition, it will be appreciated that these initial lines of contact 46 between the side surfaces of the bit wings 32 and recess wings 20 are essentially parallel to the root 36 of the bit 30, as illustrated by the dashed lines in ~igure 27. In other words, these lines of contact 46 form substantially the same 5-degree 45iminute angle with respect to the axis of the bit 30 corresponding to the Ph;ll;rs-standard root angle. Moreover, as the level of applied torque increases and the bit 30 begins to deform the recess 20, the lines of contact expand radially outwardly in parallel fashion along the side faces of the bit wings 32, as indicated by the shaded portion 50 illustrated in Figure 29. m is serves to significantly increase the level of torque that can be transmitted from the screwdriver bit 30 to the fastener 24 while confining the areas of engagement to the side surfaces of the bit wings 12. This distinction between the present invention and the standard Phillips bit is illustrated in Fig~lres 14 and 26.
Significantly, the deformation of the recess 20, as illustrated in Figure 26, along the sidcwPll~ of the recess wings 21 d oe s not add to the relatively small cam-out forces generated by the application of torque along the initial lines of contact 46 between the bit 30 and recess 20. Accordingly, driving eny~ nL between the screwdriver bit 30 and the fastener 24 can easily be maintained with the application of a modest amount of downforce. m is ph~ l of the present invention is illustrated and diay~ d in Figures 27 and 28. As previously noted, the application of torque from the bit 30 to the fastener 24 along the initial lines of contact 46 on the side ~00~62 surfaces of the bit wings 32 is represented by the dotted lines in Figure 27. m e ap~lic~tion of force in this manner results in the generation of an outwardly directed force c~l~onenL perpendicular to the lines of contact, as indicated by the arrows 45 in Figure 27.
m is, in turn, results in the generation of an equal and opposite force vector designated "Z" in the ~ccnmr~ying vector force diagram shown in Figure 28. In view of the a~lo~imated 5-degree 45iminute angle of the for oe ~Lol "Z" relative to the axis of the bit 30, the for oe vector "Z" is oamprised ~led~,linantly of a horizontal force component, l~hple~ "X", and a relative small vertical force component, labeled "Y". In fact, the vertical force cYxnponent "Y" tending to cause the bit 30 to cam-out of the re oe ss 20 is only equal to approximately a factor of 0.10 (i.e., sin 5 45') times the magnitude of the force vector "Z". Accordingly, when compared to a standard Ph;]l;ps bit 10, significantly less downward force is required from the O~e~a~Or to retain the present bit 30 in the recess 20 of a standard Phillips-head fastener 24, even at high levels of applied torque.
From the above discussion, it will be appreciated that the screw~river bit 30 according to the present invention is able to significantly reduce the cam-out for oe associa~ with a standard Ph;ll;ps screwdriver bit 10 by ~ ~.Ling the radially outward facing bit wing surfaces 34 from contacting the re oe ss 20 in the head 22 of the fastener 24. Due to the angle of these bit wing surfaces 34, the application of foroe along these surfa oe s is believed to be the greatest cause of cam-out in a standard Phillips design. m erefore, the present screwdriver bit 30 is capable of deforming the recess 20~ Z
wings 21 in a Phillips-head fastener 24 to the degree illustrated in Figure 26 before significant cam,out forces will be ~neLa~ed. At the stage illustrated in Figure 26, torque is being applied along virtually the entire side surfaces of the bit wings 32 from the initial lines of contact 46 adjacent the root 36 of the bit to the outer radial edges 48 of the bit wings 32.
Finally, it will be appreciated that, in view of the radially symmetrical design of the invention, the present screwdriver bit 30 is capable of applying significantly greater torque loads than a stan~rd Phillips bit in either r~tational direction. m erefore, unlike certain existing modified Phillips designs which radially offset the bit winas and are, therefore, primarily useable in only one rotational direction, the present invention is equally useful for tightly setting standard Philips screws and for "breaking free" and removing "frozen" Phillips fasteners.
While the above description constitutes the preferred ~mha~;m~nt of the invention, it will be appreciated that the invention is susceptible to dification, variation, and change without departing from the proper scope or fair mPAn;ng of the Acc~mpAnying claims.
Claims (39)
1. A driver for a standard Phillips-head fastener having a cross-shaped recess formed in the head thereof defining recess wings having outer radial surfaces that are tapered toward a common point at a predetermined standard wing angle relative to the axis of the fastener, the side surfaces of adjoining recess wings defining a predetermined standard included angle that remains substantially constant from the bottom of said recess to the top of said recess, and wherein the sidewalls of said recess wings are oriented at a predefined standard root angle relative to said axis such that the thickness of aid recess wings expands in the axial direction from the bottom of the recess to the top of the recess; said driver including a bit portion adapted for insertion into said recess comprising:
four bit wings having radially outward facing surfaces that are tapered toward a common point at an angle compatible with said standard wing angle relative to the axis of said bit portion and wherein the thickness of said bit wings adjacent the roots of said bit wings increases gradually away from said common point in the axial direction at an angle compatible with said standard root angle but remains substantially constant along said tapered radially outward facing surfaces and further wherein the side surfaces of said bit wings comprise generated surfaces that define an included angle in a plane substantially normal to said bit portion axis that progressively changes in the axial direction from a first angle adjacent the base of said bit wings to a second different angle adjacent the radially outer tips of said bit wings.
four bit wings having radially outward facing surfaces that are tapered toward a common point at an angle compatible with said standard wing angle relative to the axis of said bit portion and wherein the thickness of said bit wings adjacent the roots of said bit wings increases gradually away from said common point in the axial direction at an angle compatible with said standard root angle but remains substantially constant along said tapered radially outward facing surfaces and further wherein the side surfaces of said bit wings comprise generated surfaces that define an included angle in a plane substantially normal to said bit portion axis that progressively changes in the axial direction from a first angle adjacent the base of said bit wings to a second different angle adjacent the radially outer tips of said bit wings.
2. The driver of claim 1 wherein said bit wings define roots therebetween that are oriented relative to the axis of said bit at an angle substantially equal to-said standard root angle.
3. The driver of claim 2 wherein the base of said bit portion is truncated.
4. The driver of claim 2 wherein said bit is adapted to engage said recess when said bit portion is inserted into said recess at the generated side surfaces of said bit wings along lines of contact adjacent and substantially parallel to said roots.
5. The driver of claim 4 wherein the area of engagement between the recess and said bit portion expands progressively radially outwardly from said lines of contact as the torque levels applied by said driver to said fastener increase.
6. The driver of claim 1 wherein a gap is formed between said radially outward facing surfaces of said bit wings and said opposing outer radial surfaces of said recess wings when said bit portion is fully inserted into said recess.
7. The driver of claim 1 wherein a gap is formed radially inward from said lines of contact between the roots of said bit portion and the opposing surfaces of said recess when said bit portion is fully inserted into said recess.
8. The driver of claim 1 wherein the base of said bit portion is truncated.
9. The driver of claim 1 wherein said bit wings are radially symmetrical such that equal levels of torque can be applied from said driver to the fastener in both rotational directions by all four bit wings.
10. The driver for a standard Phillips-head fastener having a cross-shaped recess formed in the head thereof, the driver having associated therewith an axis and including a bit portion adapted for insertion into said recess comprising:
wing means symmetrical about any plane containing the axis of the driver and having side surfaces defining roots therebetween for rotationally driving said fastener initially adjacent said roots and progressively radially outward therefrom as the torque levels applied by said driver to said fastener increase.
wing means symmetrical about any plane containing the axis of the driver and having side surfaces defining roots therebetween for rotationally driving said fastener initially adjacent said roots and progressively radially outward therefrom as the torque levels applied by said driver to said fastener increase.
11. The driver of claim 10 wherein said wing means comprises four equally radially spaced bit wings defined by generated side surfaces that in turn define an included angle between adjoining bit wings that progressively changes in the axial direction from a first predetermined angle at the base of said bit wings to a second different predetermined angle adjacent the radially outer tips of said bit wings.
12. The driver of claim 11 wherein the radially outwardly facing surfaces of said bit wings are tapered toward a common point at an angle relative to the axis of said bit portion substantially equal to the Phillips-standard wing angle.
13. The driver of claim 12 wherein the roots of said bit portion are oriented relative to said bit axis at an angle substantially equal to the Phillips-standard root angle.
14. The driver of claim 13 wherein a gap is formed between said radially outward facing surfaces of said bit wings and the opposing outer radial surfaces of said recess when said bit portion is fully inserted into said recess.
15. The driver of claim 13 wherein a gap is formed
16 between the root areas of said bit portion and the opposing surfaces of said recess when said bit portion is inserted into said recess.
16. The driver of claim 13, wherein the base of said bit portion is truncated.
16. The driver of claim 13, wherein the base of said bit portion is truncated.
17. A driver for a standard Phillips-head fastener having a cross-shaped recess formed in the head thereof, the driver having associated therewith an axis and including a bit portion symmetrical about any plane containing the axis of the driver and adapted for insertion into said recess comprising:
wing means having generated side surfaces and defining roots therebetween for rotationally driving said fastener on said side surfaces in the same manner in both rotational directions.
wing means having generated side surfaces and defining roots therebetween for rotationally driving said fastener on said side surfaces in the same manner in both rotational directions.
18. The driver of claim 17 wherein said wing means comprise four equally radially spaced bit wings defined by generated side surfaces that in turn define an included angle between adjoining bit wings that progressively increases from a first predetermined angle at the base of said bit wings to a second greater predetermined angle at an axially spaced distance therefrom.
19. The driver of claim 17 wherein the radially outwardly facing surface of aid bit wing converge toward a common point at an angle relative to the axis of said bit portion substantially equal to the Phillips-standard wing angle.
20. The driver of claim 17 wherein the roots of said bit portion are oriented relative to aid bit axis at an angle substantially equal to the Phillips-standard root angle.
21. The driver of claim 20 wherein a gap is formed between said radially outward facing surfaces of said bit wings and the opposing outer radial surfaces of said recess when said bit portion is fully inserted into said recess.
22. The driver of claim 20 wherein a gap is formed between the root areas of said bit portion and the opposing surfaces of said recess when said bit portion is inserted into said recess.
23. The driver of claim 20 wherein the base of said bit portion is truncated.
24. The method of supplying torque to a standard Phillips-head fastener having a standard Phillips cross shaped recess formed in the head thereof, including the steps of: inserting into said standard Phillips-head recess the bit portion of a driver having four radially symmetrical bit wings that are adapted to engage said recess along lines of contact on the side surfaces of said bit wings adjacent and substantially parallel to the roots of said adjoining bit wings, and rotating said driver so that torque is initially applied to said fastener along said lines of contact.
25. The method of claim 24 further including the step of progressively expanding the areas of contact between said bit portion and said recess in a radially outward direction over said side surfaces of aid bit wings as the level of torque applied by said driver to said fastener in a first rotational direction increases.
26. The driver of claim 10 wherein said bit wings have radially outward facing surfaces which have a substantially uniform width.
27. The driver of claim 10 wherein said wing means initially drive said fastener along lines of contact with said recess that are substantially parallel to said roots.
28. The driver of claim 10 wherein said wing means comprises four bit wings that are configured to rotationally drive the fastener in the same manner in both rotational directions.
29. The driver of claim 17 wherein said wing means are adapted to rotationally drive said fastener in both rotational directions initially adjacent aid roots and progressively radially outward therefrom along aid side surfaces as torque levels applied by said driver to said fastener increase.
30. The driver of claim 29 wherein said wing means initially engage said recess and drives said fastener along lines of contact adjacent and substantially parallel to said roots.
31. The method of claim 25 further including the step of progressively expanding the areas of contact between said bit portion and said recess in a radially outward direction over said side surfaces of said bit wings as the level of torque applied by said driver to said fastener in a second opposite rotational direction increases.
32. The method of claim 24 wherein each of said four bit wings drives the fastener in the same manner in both rotational directions.
33. A driver for applying torque to a fastener having a standard Phillips cross-shaped recess formed in the head of the fastener, the standard Phillips cross-shaped recess comprising four equally radially spaced recess wings having side surfaces and outer radial surfaces, the outer radial surfaces thereof converging toward a common point at a predefined standard wing angle relative to the axis of the fastener, the side surfaces of adjoining recess wings defining a predefined standard included angle that remains substantially constant from the bottom of said recess wings to the top of said recess, and wherein the sidewalls of said recess wings are angled at a predefined standard root angle relative to said axis;
the driver having associated therewith an axis and including a bit portion symmetrical about any plane containing the axis of the driver and adapted for insertion into said recess comprising:
four bit wings having side surfaces and radially outward facing surfaces, the radially outward facing surfaces converging at an angle relative to the axis of said bit portion compatible with said predefined standard wing angle, and wherein the side surfaces of adjoining bit wings define a root that is oriented relative to said axis at an angle substantially equal to said standard root angle, and further wherein said bit wings are configured such that when said bit portion is inserted into the recess of a standard Phillips head fastener, initial contact is created between the recess and said bit portion on the side surfaces of each of aid bit wings along lines of contact adjacent and substantially parallel to said roots with a gradually increasing gap formed between the side surfaces of said bit wings and the corresponding side surfaces of said recess wings in a radially outward direction from said lines of contact.
the driver having associated therewith an axis and including a bit portion symmetrical about any plane containing the axis of the driver and adapted for insertion into said recess comprising:
four bit wings having side surfaces and radially outward facing surfaces, the radially outward facing surfaces converging at an angle relative to the axis of said bit portion compatible with said predefined standard wing angle, and wherein the side surfaces of adjoining bit wings define a root that is oriented relative to said axis at an angle substantially equal to said standard root angle, and further wherein said bit wings are configured such that when said bit portion is inserted into the recess of a standard Phillips head fastener, initial contact is created between the recess and said bit portion on the side surfaces of each of aid bit wings along lines of contact adjacent and substantially parallel to said roots with a gradually increasing gap formed between the side surfaces of said bit wings and the corresponding side surfaces of said recess wings in a radially outward direction from said lines of contact.
34. The driver of claim 33 wherein the contact area between the recess and said bit portion expands progressively radially outwardly from said lines of contact as the torque levels applied by said driver to said fastener increase.
35. The driver of claim 33 wherein said radially outward facing surfaces of said bit wings have a substantially uniform width from the base of said bit wings to the end of said taper.
36. The driver of claim 35 wherein a gap exists between said radially outward facing surfaces of said bit wings and said opposing outer radial surfaces of aid recess wings when said bit portion is fully inserted into said recess.
37. The driver of claim 33 wherein a gap exists radially inward from said lines of contact between the roots of said bit portion and the opposing surfaces of said recess when said bit portion is fully inserted into said recess.
38. The driver of claim 33 wherein the base of said bit portion is truncated.
39. The driver of claim 33 wherein aid bit wings are configured so that all four bit wings rotationally drive the fastener in the same manner in both rotational directions.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US27000088A | 1988-11-14 | 1988-11-14 | |
| US270,000 | 1988-11-14 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2002162A1 CA2002162A1 (en) | 1990-05-14 |
| CA2002162C true CA2002162C (en) | 1995-10-03 |
Family
ID=23029478
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2002162 Expired - Fee Related CA2002162C (en) | 1988-11-14 | 1989-11-03 | Screwdriver bit for phillips-head fasteners |
Country Status (4)
| Country | Link |
|---|---|
| EP (2) | EP0551930A3 (en) |
| JP (1) | JPH0811368B2 (en) |
| AU (3) | AU4458389A (en) |
| CA (1) | CA2002162C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AUPQ432899A0 (en) | 1999-11-29 | 1999-12-23 | Fcd (Holdings) Pty Limited | Rotatable drilling bit |
| US12016280B2 (en) | 2022-08-02 | 2024-06-25 | 2by2 Industries, LLC | Landscape timber system |
Family Cites Families (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL42923C (en) * | 1934-07-03 | |||
| US2046838A (en) * | 1934-07-03 | 1936-07-07 | Phillips Screw Co | Screw driver |
| US2474994A (en) * | 1942-12-30 | 1949-07-05 | American Screw Co | Screw socket |
| US2389129A (en) * | 1943-09-03 | 1945-11-20 | Joseph H Bishop | Universal screw driver |
| US2646829A (en) * | 1948-07-13 | 1953-07-28 | Res Eng & Mfg | Driver for recessed head fasteners |
| US2601453A (en) * | 1948-07-21 | 1952-06-24 | Res Eng & Mfg | Driving tool for socket head fasteners |
| US2764197A (en) * | 1952-10-07 | 1956-09-25 | North American Aviation Inc | Driver for recessed head screws |
| FR1330358A (en) * | 1961-05-26 | 1963-06-21 | Guest | Improvements to threaded metal fasteners and fitting tools for these elements |
| US3234982A (en) * | 1963-06-24 | 1966-02-15 | Gardner Denver Co | Driver for recessed head fasteners |
| GB1065348A (en) * | 1965-04-26 | 1967-04-12 | Stead & Company Ltd J | Improvements in or relating to screwdrivers and their manufacture |
| US3654974A (en) * | 1970-04-08 | 1972-04-11 | Bertron Otis Barnes | Screw drivers |
| US3658105A (en) * | 1970-05-04 | 1972-04-25 | John Burt | Fastener driving arrangement |
| US3913647A (en) * | 1974-05-28 | 1975-10-21 | Edward T Arnn | Screw driver |
| CA1066542A (en) * | 1977-03-07 | 1979-11-20 | Bernard F. Reiland | Lobular socket head fastener with service slot |
| FR2469250A1 (en) * | 1979-11-12 | 1981-05-22 | Defougeres Pierre | Tapered cruciform bit for screw-driver - has identical tapered wings at ninety degree intervals and is in one pressed piece |
| DE3174306D1 (en) * | 1980-07-23 | 1986-05-15 | Gkn Screws Fasteners Ltd | Fastener and driver combination |
| US4625598A (en) * | 1985-05-10 | 1986-12-02 | Frank Wolfram | Positive engagement screw driver tool |
-
1989
- 1989-11-03 CA CA 2002162 patent/CA2002162C/en not_active Expired - Fee Related
- 1989-11-03 EP EP19930104130 patent/EP0551930A3/en not_active Withdrawn
- 1989-11-03 EP EP89311411A patent/EP0369655A3/en not_active Withdrawn
- 1989-11-13 AU AU44583/89A patent/AU4458389A/en not_active Abandoned
- 1989-11-13 JP JP29252589A patent/JPH0811368B2/en not_active Expired - Lifetime
-
1993
- 1993-03-19 AU AU35359/93A patent/AU665621B2/en not_active Ceased
-
1995
- 1995-11-08 AU AU37729/95A patent/AU3772995A/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| EP0551930A2 (en) | 1993-07-21 |
| AU3772995A (en) | 1996-01-11 |
| AU3535993A (en) | 1993-05-20 |
| AU4458389A (en) | 1990-05-17 |
| AU665621B2 (en) | 1996-01-11 |
| EP0551930A3 (en) | 1993-08-18 |
| JPH02237773A (en) | 1990-09-20 |
| JPH0811368B2 (en) | 1996-02-07 |
| CA2002162A1 (en) | 1990-05-14 |
| EP0369655A3 (en) | 1990-07-11 |
| EP0369655A2 (en) | 1990-05-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |