Patent Grant
11446797
This invention relates to driving tools, and more particularly to devices that are used to releasably hold fasteners in place at the working ends of driving tools.
Craftsmen, handymen, and other users of screw type fasteners have, since shortly after the invention of such fasteners, been frustrated by the difficulty posed by the need to occasionally install them in locations that are not easily accessed. Prior art is extensive, and in and of itself is evidence of the long held and widespread desire of artisans and the common handyman to devise a simple, inexpensive and versatile solution to this problem.
As early as 1870, U.S. Pat. No. 99,781 to Martyn demonstrates a solution that involves the employment of a cylindrical sleeve, actuated by a spring, to hold the screw in a favorable position with the driver head while the screw is driven, and to allow the sleeve to retract out of the way as the screw head comes into contact with the surface. U.S. Pat. No. 1,593,233 to Wilson in 1926 and U.S. Pat. No. 3,288,185 to Clark in 1966 are other examples of this approach. These devices are deficient in two basic ways. First, because the sleeve does not positively hold the screw to the driver head, the screw can fall free when the device is angled downward, and in all but an upward orientation the screw is so loosely in contact with the driver head that damage to the kerf is likely as the driving process occurs. Secondly, in order to work even reasonably well, the diameter of the sleeve must closely match the diameter of the screw head, necessitating multiple devices if it is to be used with a variety of screw sizes.
To overcome these deficiencies, inventors have employed a variety of remedies that involve flexible, resilient members that springably engage the screw head as a means of retaining it to the driver. U.S. Pat. No. 845,978 to Rappelee in 1907 employs a combination of a compression spring with a pair of screw holding jaws that are sleeved to the driver, the tips of said jaws being inwardly formed in a convex manner. This device, however, relies on a specifically modified driver and a permanent attachment of the device, the result being not only the requirement of a modification to the driving tool, but a modification that significantly weakens it. Additionally, the invention in no way envisions anything other than a device that must be permanently and specifically matched to the driver, thus eliminating the possibility of portability or minor adjustment to accommodate different fasteners.
U.S. Pat. No. 1,698,521 to Wood in 1929 combines the elements of a spring actuated guiding sleeve with springable fingers, said fingers being formed at the tips in a manner that lends itself to the retaining of a screw head. This invention, however, also relies on a driving tool that is specifically designed or modified to the requirements of the device, and as such is neither portable nor adjustable in the cause of dealing with different sizes and types of screws. Additionally, the sleeve, in order to be effective, as mentioned earlier, must closely match the diameter of the screw head. Furthermore, the sleeve presents an ineffective enclosure that prevents visual access to the driver head, thus making more difficult the alignment of the kerf with the driver head. Perhaps most significant of the drawbacks of this invention is its complexity, which involves the costly manufacture and assembly of multiple components that must have closely matched tolerances.
U.S. Pat. No. 1,712,196 to Burger et al. in 1929 features a sleeve with attached springable fingers, the tips of which are formed in a manner that allows for the insertion and retention of a screw head. The deficiencies of this invention are several. As with Wood, the sleeve not only has limited use unless its size is closely matched to that of the screw head, it presents an impediment to the visual alignment of the kerf with the screw head that often leads to the unnecessary and annoying need to “jockey” the two together. Additionally, though not as complex as Wood, it requires the costly manufacture and assembly of parts that demand close tolerances. Furthermore, this invention in no way envisions any means of actuation of the device on the driver other than manually sliding it to and fro, and therefore will not self grasp a fastener when it is being removed from a difficult to access location.
U.S. Pat. No. 4,744,273 to Bartok in 1988 features a generally U-Shaped attachment of resilient sheet metal that is adapted to be axially captured relative to the drive shank and wrench socket of a wrench assembly so as to extend along opposite sides of the socket and then inwardly of the fastener receiving opening in the wrench socket to releaseably retain the head of the fastener therein during application or removal of the fastener from a mating part. The deficiencies of the invention are limiter fastener use (hex head bolts), limited driver type (socket wrench) and a high profile as the attachment rides along the outside of the drive socket.
U.S. Pat. No. 5,515,755 to Kung in 1996 features an insulated fastener retainer that includes an oval sleeve and oval ring coupled by a plurality of connectors and supporting a pair of oppositely positioned elongated beams. The beams are secured to the flat sides of the oval ring at one end and are received within insulating blocks at the outer ends. A pair of resilient jaws having grip portions is coupled to the insulating blocks and are movable in response to movement of the elongated beams. The fastener retainer is received upon a screwdriver shaft and is maintained thereon by the oval sleeve. The elongated beams and jaws are separated by the user's application of a squeezing force to the ends of the oval ring thereby distorting the oval ring and separating the fastener retainer jaws. The deficiencies of the invention are limited fastener use and driver type due to shape of the retention features, complex construction and weak fastener retention.
U.S. Pat. No. 7,069,826 to Tilton in 2006 features an attachment for drivers that comprises a shaft collar, a spring, and a grasper, the grasper comprising an upper and a lower guide ferrule, joined concentrically by a pair of supports, and extending parallel from the lower ferrule a plurality of flexible fingers, each having at its distal end an inward facing detent that is substantially fulcrum shaped. The collar and spring are inserted between the ferrules, with the collar abutting the upper, the spring abutting the lower and the collar. A driver is inserted through the ferrules, collar, and spring until the tip is just shy of the detents, and the collar is then affixed to the driver shaft. A screw head is forced past the detents, the fingers yielding, and brought into proper contact with the driver tip, the fingers flexing back such that the detents hold the screw firmly to the driver. The deficiencies of the invention are bulky multi-piece construction and limited fastener usage due to specific retention features for each fastener head.
The following is a summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description and the defining claims that are presented later.
The present invention provides a low-profile fastener retaining device that provides for strong fastener retention, low foreign object damage (FOD) risk, compatibility with a wide range of driving tool and fastener types and sizes that is inexpensive to manufacture and capable of driving the fastener at an angle. The present invention addresses this problem with a single-sided device to releasably hold the fastener. The single-sided approach supports the low-profile requirement but necessitates a different design of the retention and release mechanisms to provide strong fastener retention.
In an embodiment, the fastener retaining device comprises an attachment mechanism (e.g., a compression sleeve, a sleeve and set screw, spot weld) configured to engage and hold the shaft of a driving tool of various sizes and shapes about an axis. A release mechanism includes a resilient arm and a lever arm joined by a fulcrum that contacts the shaft of the driving tool. The resilient arm extends from the attachment mechanism along and spaced apart from the axis and the lever arm extends from the fulcrum at an angle to the axis. A single fork, connected to the lever arm, has first and second arms that extend to either side of and at least to the level of the axis to define an opening facing the axis to receive the shaft of a fastener of various sizes and hold the head of the fastener to the working end of the driving tool in a retained position. The release mechanism is responsive to the application of a force to elastically deform the resilient arm causing the lever arm to pivot on the fulcrum moving the fork away from the axis to a released position to release the fastener. The release mechanism is responsive to the removal of the force to return the fork to the retained position.
In an embodiment, a method of using a driving tool to install a fastener into a material comprises engaging the attachment mechanism of the fastener retaining device to the shaft of the driving tool such that the fulcrum contacts the shaft and the fork receives the shaft of the fastener and holds the head of the fastener to the working end of the driving tool in a retained position. The driving tool is used (e.g., rotated) to partially engage the fastener into the material. Force is applied to elastically deform the resilient arm to cause the lever arm to pivot on the fulcrum moving the fork away from the axis to a released position to release the fastener. The driving tool is used to complete the engagement of the fastener into the material. The driving tool is withdrawn and the force is removed allowing the fork to return to the retained position. To drive the fastener at an angle, the driving tool is oriented with the release mechanism facing away from the material such that the fork does not engage the material and pre-maturely release the fastener.
In an embodiment, a method of using a driving tool to remove a fastener from a material comprises engaging the attachment mechanism of the fastener retaining device to the shaft of the driving tool such that the fulcrum contacts the shaft and the fork is held in a retained position. A force is applied to elastically deform the resilient arm to cause the lever arm to pivot on the fulcrum moving the fork away from the axis to a released position. The driving tool is used to partially remove the fastener from the material. The force is removed allowing the fork to return to the retained position to hold the head of the fastener to the working end of the driving tool. The driving tool is used to completely remove the fastener from the material. The driving tool and retained fastener are withdrawn. To drive the fastener at an angle, the driving tool is oriented with the release mechanism facing away from the material such that the fork does not engage the material and pre-maturely release the fastener.
In an embodiment, a method of fabricating a fastener retaining device for retaining a fastener to the working end of a driving tool comprises providing a sheet of resilient material such as spring steel. A one-piece form including a transverse rectangular member, a longitudinal rectangular member and a fork is cut from the sheet along an axis. The one-piece form is mechanically manipulated to exceed the elastic modulus of the resilient material and induce plastic deformation to form the fastener retaining device. The manipulation includes rolling the transverse rectangular member around the axis to form a compression sleeve, bending the longitudinal rectangular member to form a release mechanism including resilient and lever arms joined by a fulcrum, and bending the fork such that an opening faces the axis. The application of a force to elastically deform the resilient arm to pivot the lever arm and fork away from the axis to a release position does not exceed the elastic modulus such that removal of the force allows the release mechanism to pivot the fork towards the axis to a retained position.
These and other features and advantages of the invention will be apparent to those skilled in the art from the following detailed description of preferred embodiments, taken together with the accompanying drawings, in which:
As previously stated, the prior art is extensive, and in and of itself is evidence of the long held and widespread desire of artisans and the common handyman to devise a simple, inexpensive and versatile solution to this problem. A particular market segment must address the need to reliably install and remove fasteners in locations that are not easily accessed and demand low-profile devices, ones that can fit through access holes not much larger than the fastener head and drive fasteners at an angle. Prior art devices are configured to hold the head of the fastener on opposing sides or around the circumference, which in turn necessitates a retention and release mechanism that is configured on opposing sides or around the shaft of the driving tool. This increases the profile of the fastener retaining device. Furthermore, such devices cannot be used to drive fasteners at an angle as one side will tend to disengage and drop the fastener. This can be a very important feature when, for example, the small access hole in a panel is some distance from the installation of the fastener. Inevitably, the two will have some degree of misalignment.
The present invention provides a low-profile fastener retaining device that provides for strong fastener retention, low FOD risk (e.g., the dropped fastener rattling around), compatibility with a wide range of driving tool and fastener types and sizes that is inexpensive to manufacture and capable of driving the fastener at an angle. The present invention addresses this problem with a single-sided device to releasably hold the fastener. The single-sided approach supports the low-profile requirement but necessitates a different design of the release and retention mechanisms to provide strong fastener retention and the capability to drive the fastener at an angle. Instead of multi-sided cams/jaws/teeth that hold the fastener head or shaft directly, a single “fork” receives the fastener shaft and pins the fastener head against the working end of the driving tool. For the single fork to “clear” the fastener head and release the fastener, the release mechanism required a larger range of motion. This was achieved by positioning the fulcrum between any applied force and the fork. In the absence of such force, the fork returns to a retained position to hold the fastener. The present invention provides for methods of using the low-profile fastener retaining device to both install and remove fasteners, if necessary, at an angle and a method of fabricating an embodiment of a one-piece device.
As used herein, a “fastener” includes a head on an externally threaded shaft. Examples include screws or bolts. The fasteners may have different types of drive heads such as blade, Phillips or hexagonal. A “driving tool” typically includes a handle for rotating a shaft having a “working end” or tip that is configured to mate with a particular type and size of fastener. Examples include screwdrivers (Philips, slotted, cruciform),
Hex Keys and socket drive tools to name a few. Rotation of the driving tool causes the fastener to rotate and engage a material such as wood, metal or a mating fastener such as a nut.
Referring now to
The compression sleeve 18 is recommended to be undersized to the shaft of the driving tool (roughly 0.75× to 0.95× the diameter of shaft of the driving tool). The resilient arm 26 should be sufficiently distanced from the axis of the compression sleeve (roughly 1× to 2× the diameter of the compression sleeve) to properly engage the lever arm 28. The resilient arm should also have sufficient engagement area to apply force 52 to the resilient arm to prevent injury or fatigue to the user. This is recommended to be roughly 5× to 10× the nominal thread size of the fastener. Fulcrum 30 should be of adequate size to rest on the shaft of the drive tool in it's relaxed state. The placement of the fulcrum is directly related to the length of resilient arm 26. The lever arm must be of sufficient length geometrically to fully clear the fastener head and is typically related to resilient arm 26 length with the lever arm typically equal or longer in length. Depending on size of the fastener this could be roughly 1× to 3× the length of the resilient arm.
In the non-actuated retained position, compression sleeve 18 exerts inward forces 44 on shaft 20 of the driving tool. The inward forces provide friction or axial forces 46 that hold the fastener retain device 10 in place and provide an axial force 48 at fork 32 that pins the fastener head 42 to the working end of the drive tool. Fulcrum 30 contacts shaft 20 of the driving tool and may or may not provide a small inward force 50 to maintain contact. As shown in
In the actuated release position, release mechanism 24 is responsive to the application of a force 52 on resilient arm 26 towards the axis 22 of the compression sleeve to elastically deform the resilient arm causing the lever arm 28 to pivot 54 on the fulcrum 30 moving the fork 32 away from the axis to a released position to release the fastener 12. Force 52 overcomes a spring tension force 56 in order to pivot. Fulcrum 30 moves along the shaft away from the attachment slightly such that the fork clears the head of the fastener as it is released. Accordingly, the release mechanism is responsive to the removal of force 52 to return the fork to the retained position. Force 52 may, for example, be provided by a user pressing down on the resilient arm or via a telescoping sleeve as will be discussed later. The release mechanism, and particularly the resilient arm, is formed from a material such as spring steel or certain plastics that exhibit an elastic modulus sufficient to provide the requisite spring tension 56 to return the fork to the retained position. The actuation does not exceed the elastic modulus of the release mechanism and thus does not induce plastic deformation. As will be described later, the entire fastener retaining device 10 may be fabricated from a single piece of material by cutting a form from the material and rolling or bending the form to create the compression sleeve, release mechanism and fork.
Referring now to
Referring now to
Referring now to
Referring now to
Referring now to
Referring now to
Referring now to
While several illustrative embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Such variations and alternate embodiments are contemplated, and can be made without departing from the spirit and scope of the invention as defined in the appended claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 99781 | Martyn | Feb 1870 | A |
| 845978 | Rappelee | Mar 1907 | A |
| 1218452 | Ohl | Mar 1917 | A |
| 1311147 | Bernisen | Jul 1919 | A |
| 1593233 | Wilson | Jul 1926 | A |
| 1659671 | Stone | Feb 1928 | A |
| 1698521 | Wood | Jan 1929 | A |
| 1712196 | Burger et al. | May 1929 | A |
| 1773483 | Guze | Aug 1930 | A |
| 1977323 | Morgan | Oct 1934 | A |
| 2206364 | Petre | Jul 1940 | A |
| 2526211 | Erickson | Oct 1950 | A |
| 2704954 | Martorella | Mar 1955 | A |
| 2753747 | Brown | Jul 1956 | A |
| 2960131 | Clark | Nov 1960 | A |
| 3178971 | Bachli | Apr 1965 | A |
| 3288185 | Clark | Nov 1966 | A |
| 3730237 | Hanzlik | May 1973 | A |
| 4455898 | Marbourg, Jr. | Jun 1984 | A |
| 4526072 | Manhoff, Jr. | Jul 1985 | A |
| 4631985 | Roberts | Dec 1986 | A |
| 4744273 | Bartok, Jr. | May 1988 | A |
| 5515755 | Kung | May 1996 | A |
| 6626347 | Ng | Sep 2003 | B2 |
| 6857343 | Easterbrooks et al. | Feb 2005 | B1 |
| 7069826 | Tilton | Jul 2006 | B2 |
| 7913593 | Dahar et al. | Mar 2011 | B2 |
| 8726769 | Jacker | May 2014 | B1 |
| 20040163500 | Walsh | Aug 2004 | A1 |
| 20060236822 | Nish | Oct 2006 | A1 |
| 20070106283 | Garcia et al. | May 2007 | A1 |
| 20070295173 | Swartz | Dec 2007 | A1 |
| 20120253355 | Murray et al. | Oct 2012 | A1 |
| Number | Date | Country |
|---|---|---|
| 1469920 | Apr 1977 | GB |
| Entry |
|---|
| “International Application Serial No. PCT/US2020/032339, International Search Report dated Nov. 9, 2020”, 5 pgs. |
| “International Application Serial No. PCT/US2020/032339, Written Opinion dated Nov. 9, 2020”, 7 pgs. |
| Number | Date | Country | |
|---|---|---|---|
| 20210197346 A1 | Jul 2021 | US |
