US3656522A

US3656522A - Screwdriver with non-slip bit coating means

Info

Publication number: US3656522A
Application number: US77611A
Authority: US
Inventors: Bjorn Rafnar Ingimarsson
Original assignee: BJORNS AIRMOTIVE CO
Current assignee: BJORNS AIRMOTIVE CO
Priority date: 1970-10-02
Filing date: 1970-10-02
Publication date: 1972-04-18
Anticipated expiration: 1989-04-18

Abstract

A tool for manually turning a threaded fastener. The example shown is a screwdriver having an integral supply of abrasive fluid stored within its handle. A supply passage extends through the axial tool shank in communication with the fluid supply and leads to an outlet orifice at the operative tip of the tool. By selectively discharging abrasive material at the tip while engaging a fastener such as a screw or similar member, one can effectively increase the frictional engagement between the tool tip and the fastener and thereby permit the application of greater torque without slippage of the tool.

Description

lngimarsson 51 Apr. 18, 1972 SCREWDRIVER WITH NON-SLIP BIT COATING MEANS [72] Inventor: Bjorn Rafnar lngimarsson C/O Bjorns Airmotive Company, Chehalis, Wash. 743622 11/1903 98591 Primary Examiner-Ther0n E. Condon [22] Filed: Oct. 2, 1970 Attorney-Wells, St. John & Roberts [2]] Appl. No.: 77,611 57 ABSTRACT A tool for manually turning a threaded fastener. The example [52] 81/ i fag shown'is a screwdriver having an integral supply of abrasive 51 I Cl B25) ls/oz/ d 5 fluid stored within its handle. A supply passage extends 'i i R 50 A D 50 E through the axial tool shank in communication with the fluid 1 0 gg 1 0 6 l3 4 /214 1 supply and leads to an outlet orifice at the operative tip of the I191 too]. By selectively discharging abrasive material at the tip while engaging a fastener such as a screw or similar member, one can effectively increase the frictional engagement [56] Rem-anus cued between the tool tip and the fastener and thereby permit the UNITED STATES PATENTS application of greater torque without slippage of the tool. 2,329,398 9/ 1943 Duffy ..145/50 D 5 Claims, 1 Drawing Figure -u2l IO E fli L} J k l9 6 SCREWDRIVEIR WITH NON-SLIP BIT COATING MEANS BACKGROUND OF THE INVENTION The invention relates to a tool for turning a threaded fastener. In general, the fasteners are of the type having a head and an axial threaded shank. It specifically relates to a screwdriver for engagement with Phillips head screws. The head has anouter surface with an axially centered slot or recess to receive a tool tip. The tip engages the slot or recess to turn the fastener about its longitudinal axis.

The resistance of such fasteners to turning forces results in reaction forces at the manually held tool that tend to force the tool tip out of the fastener slot or recess. This backing off of the tool often causes damage to fastener head and to the tool tip. It also requires that additional manual force be exerted on the tool in an axial direction to insure that the tool and fastener will not be separated. Depending upon the extent of such resistance, it may not be possible to properly seat a particular fastener by manual application of torque through a selected screwdriver.

To increase the frictional engagement between the tool tip and the fastener head, it has been previously proposed to roughen the tip. This is discussed in prior US. Pat. No. 3,21 1,199. However, as with all tool surfaces, the permanently roughened surfaces are subject to wear and eventually must be discarded or replaced.

According to the present disclosure, a replaceable supply of abrasive fluid is stored within the handle of the tool and is selectively directed through a delivery passage to an orifice at the tool tip. The party using the tool can, at any time, replenish the reservoir supply within the handle. He has control to direct abrasive fluid to the tip when necessary.

SUMMARY OF THE INVENTION The invention disclosed relates to a tool for applying rotational torque to a fastener. The tool includes a longitudinal shank with an operative tip end adapted to engage the fastener. A grip is mounted at the remaining end of the shank. The improvement relates to the provision of a source of friction enhancing material within the grip, an elongated aperture extending through the shank in communication with the tip end and the source of friction enhancing material, and means for selectively propelling material from the source through the aperture and to the tip end of the tool.

A first object of this invention is to provide an improved tool with friction enhancing capability, having the same essential exterior structure common in such tools today.

A second object of this invention is to provide means for selectively replenishing the supply of friction enhancing material at the tip end of a screwdriver or similar tool without requiring additional implements or attachments.

A third object of the invention is to provide means for enhancing the frictional engagement of a screwdriver or similar tool, thereby greatly increasing the life of the tool and its effectiveness in actual use.

These and further objects will be evident from the following disclosure, taken also with the accompanying drawing, which illustrates a preferred embodiment of the invention.

DESCRIPTION OF THE DRAWING The drawing illustrates a screwdriver constructed according to a preferred form of the invention, the left side of the drawing being illustrated in cross-section and the right side being in elevation. The intermediate portion of the tool shank is broken out of the view.

DESCRIPTION OF THE PREFERRED EMBODIMENT The general concept included in the embodiment of the invention shown in the drawing relates to the construction of a screwdriver or other tool for manually applying rotational torque to a fastener. It includes a source of friction enhancing material within the tool grip in communication with the operative tip of the tool by means of an elongated aperture formed through its shank. While illustrated specifically with respect to a Phillips screwdriver, it should be understood that the tool might be of other construction designed to supply torque to a threaded fastener through other configurations of operative tips or fastener receiving recesses.

The present improvement is particularly applicable to a hand tool, which is normally turned slowly and at varying angles to the fastener Because of the use of the tool'for hand engagement of fasteners, a given amount of free movement must be designed between the tip and the fastener head. This freedom of movement increases the possibility of slippage and damage to either the tool tip, the fastener head, or both.

As shown in the drawing, the modified screwdriver incorporating the invention includes a manual grip 10 of plastic resin, wood, rubber or other suitable material, having conventional exterior longitudinal ribs 11 to facilitate the manual engagement thereof. A cylindrical shank 12 projects outwardly from the grip 10 and is centered along its axis. The shank 12 may be of any desired length or diameter, depending upon the purpose of the tool. At the remaining end of shank 12 is a tip configuration 13 shown for illustration as being a screwdriver tip designed to engage a Phillips recess.

According to this disclosure, a collapsible reservoir or cartridge of friction enhancing material is mounted within the grip 10 and is generally designated by the numeral 14. The reservoir or cartridge 14 might be made of a flexible plastic resin impermeable to the material contained therein. It is formed in a general cylindrical shape, having an axial outlet at 15, the diameter of outlet 15 being restricted and of much smaller dimension than the remainder of cartridge 14.

Cartridge 14 fits within an axial cavity 16 formed through the outer end of grip 10. The outlet 15 fits within a complementary recess 17 formed at the end of shank 12 in open communication with cavity 16. The recess 17 is adapted to seal against the outer surfaces of outlet 15 to provide a liquid-tight seal.

Leading from recess 17 is an elongated axial aperture 19 having a cylindrical configuration and substantially the same diameter as outlet 15. Aperture 19 extends through the length of shaft 12 and leads to a restricted orifice 18 of reduced diameter. The orifice 18 extends to the outer tip of shank l2 and terminates at an axial opening indicated at 20.

The collapsible cartridge 14 contains liquid or other material adapted to enhance frictional engagement of one metal element relative to another. This liquid, shown at 21, might be of any suitable composition. As an example, grinding compounds used in machine shop operations have been used in this application together with abrasive particles suspended therein, such as carborundum dust. A mixture of a commercial grinding compound and carborundum dust, having sufficient viscosity to remain at the interior of the screwdriver until propelled outward, is most effective in increasing the operational friction between the tip 13 and the fastener engaged thereby.

In use, the cartridge 14 is placed within the grip l0, and its outer end can be selectively depressed to propel the liquid or other material therein through outlet 15 and aperture 19 to orifice 18, where it is ejected at outlet 20. This is preferably accomplished with the tip 13 engaged in the recess of a screw or other fastener. The exiting material will be forced between the tip 14 and the fastener recess, and will thereby be spread about the surfaces of the screwdriver tip 13. The increased frictional engagement improves the turning capability of the manual tool and assures greater efficiency in turning the fastener, while increasing the operational life of the tool and fasteners.

As the friction enhancing material 21 is ejected from the cartridge 14, the interior of cartridge 14 will progressively be collapsed by the pushing of ones finger or another object within cavity 16. This is indicated in the drawings at 22, which shows the condition of the cartridge 14 when partially empty.

This collapsing action continues until the depressed portion of cartridge 14 bottoms at the opposite end of cartridge 14 adjacent to outlet 15. At that time, the cartridge 14 can be removed from the tool and a new cartridge substituted in its place.

Various modifications might be made in the structure illustrated without deviating from the basic concept set out herein of providing a source of friction enhancing material within a reservoir at the grip of a tool in communication with the tip thereof through an axial aperture in the tool shank.

For instance, a slidable plunger might be sealed against the walls of the cavity 16 and the replaceable cartridge structure eliminated all together. Compressed air or other gas might be used as a propellant to exert force against the cartridge and force the material to the tip of the tool. In addition, the tool itself need not be designed precisely as illustrated. It might include replaceable tip elements which in turn would be apertured to direct the liquid or other fluid to the operative tip end. The friction enhancing material need not be liquid in form. It can be dry or in the form of a thick paste.

Minor modifications might be made in the device without deviating from the basic concepts disclosed herein. For these reasons, only the following claims are intended to be restricting definitions of the scope of the invention.

Having thus described my invention, I claim:

1. In a tool for applying rotational torque to a fastener of the type comprising:

a longitudinal shank;

an operative tip end at one longitudinal end of the shank adapted to engage the fastener;

and a grip at the remaining end of the shank adapted to be manually grasped for turning of the shank thereby during torque application;

the improvement comprising:

a source of friction enhancing material located within the an elongated aperture extending longitudinally through the shank, said aperture being in open communication with the shank exterior at the tip end thereof and with said sourceof friction enhancing material;

and means on said grip operatively associated with said source of friction enhancing material for selectively propelling the material from said source, through the aperture along said shank and to the shank exterior at the tip end thereof.

2. The tool improvement as set out in claim 1 wherein the grip includes an open cavity formed coaxially with the shank aperture and in open communication therewith;

and a collapsible container having an axial outlet, said container being adapted to be seated within the cavity of the grip with its outlet in communication with the shank aperture.

3. The tool improvement as set out in claim 2 wherein the cavity of the grip extends axially through the end of the grip opposite to said shank for permitting access to the collapsible container therein.

4. The tool improvement as set out in claim 1 wherein the tool is an axial screwdriver.

5. The tool improvement as set out in claim 1 wherein the tool is a Phillips type screwdriver.

Claims

1. In a tool for applying rotational torque to a fastener of the type comprising: a longitudinal shank; an operative tip end at one longitudinal end of the shank adapted to engage the fastener; and a grip at the remaining end of the shank adapted to be manually grasped for turning of the shank thereby during torque application; the improvement comprising: a source of friction enhancing material located within the grip; an elongated aperture extending longitudinally through the shank, said aperture being in open communication with the shank exterior at the tip end thereof and with said source of friction enhancing material; and means on said grip operatively associated with said source of friction enhancing material for selectively propelling the material from said source, through the aperture along said shank and to the shank exterior at the tip end thereof.

2. The tool improvement as set out in claim 1 wherein the grip includes an open cavity formed coaxially with the shank aperture and in open communication therewith; and a collapsible container having an axial outlet, said container being adapted to be seated within the cavity of the grip with its outlet in communication with the shank aperture.