Separable Securing Means Patents (Class 433/13)
  • Patent number: 6358045
    Abstract: A self-ligating orthodontic bracket comprised of a ligating member containing a coil spring segment for extending the ligating member over an archwire or retainer wire and over one or more tie wings to secure the archwire or retainer wire in the bottom of a slot in the bracket. The ligating member containing the coil spring may have ends that are engaged in opposing mesially-distally extending bores in one side of the bracket body, with the ligating member being engaged with one or more tie wings on an opposite side of the bracket body. Alternatively, the ligating member may form a closed loop with the ligating member engaged under both occlusally-projecting and gingivally-projecting tie wings or engaged under one or more tie wings on one side of the bracket body and passing through a mesially-distally extending bore on the opposite side of the bracket body.
    Type: Grant
    Filed: March 23, 2000
    Date of Patent: March 19, 2002
    Assignee: Ormco Corporation
    Inventors: Farrokh Farzin-Nia, Rohit C. L. Sachdeva, Thomas V. Selkee
  • Patent number: 6203317
    Abstract: An orthodontic elastomeric appliance with a polymer coating that becomes slippery when wetted, and a method of making the appliance which comprises the steps of forming an appliance of elastomeric material and coating the appliance with a polymer film capable of making the appliance slippery when wetted.
    Type: Grant
    Filed: July 19, 2000
    Date of Patent: March 20, 2001
    Assignee: TP Orthodontics, Inc.
    Inventor: Thrumal Davanathan
  • Patent number: 6168429
    Abstract: An insert for generic or custom preadjusted edgewise brackets. The device is formed of metallic material or synthetic material, or resilient elastomeric material. The device will capture and retain the orthodontic archwire into the archwire slot of the orthodontic edgewise bracket. The device includes a region aligned with the archwire slot in the edgewise bracket to position, but not frictionally interfere with the archwire, because it does not put pressure on the archwire, but creates a tunnel for the archwire to easily slide through. The crescent shaped horizontal anchors defined on the device cooperate with the underside of the tiewings on the edgewise bracket to maintain the device in position. The crescent shape provides room for other ancillary devices to be placed on the bracket and secured behind the tiewings when the device is in place.
    Type: Grant
    Filed: October 9, 1999
    Date of Patent: January 2, 2001
    Assignee: Jelaga Incorporated
    Inventor: William Burns Terrell Brown
  • Patent number: 6168428
    Abstract: In one embodiment, a pre-engaging orthodontic bracket includes a body having a lingual surface for attachment to a tooth, a pair of laterally spaced gingival tie wings and a pair of laterally spaced occlusal tie wings. The gingival and occlusal tie wings project from a labial surface of the body. An archwire slot extends mesiodistally across the body and between the gingival and occlusal tie wings at opposed mesial and distal sides of the body to accomodate an archwire. A shutter is moveable between an open position in which placement and removal of an archwire is facilitated, and a closed position in which placement and removal of an archwire is inhibited.
    Type: Grant
    Filed: July 23, 1999
    Date of Patent: January 2, 2001
    Inventor: John C. Voudouris
  • Patent number: 6071119
    Abstract: A self-ligating orthodontic bracket has a latch that is movable from a slot-open position to a first closed position or a second closed position. In the first closed position of the latch, the latch engages an archwire with sufficient force to provide active orthodontic therapy. In the second closed position, the effective labial-lingual dimension of the archwire slot is somewhat greater than the overall labial-lingual dimension of the archwire such that the bracket provides passive orthodontic therapy.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: June 6, 2000
    Assignee: 3M Innovative Properties Company
    Inventors: James D. Christoff, John S. Kelly, Evangelos G. Georgakis
  • Patent number: 6042373
    Abstract: An archwire locking device for an orthodontic bracket system is provided. The system includes a series of conventional edgewise brackets which engage the teeth of a patient by means of an adhesive which bonds the bracket to the tooth. Each bracket includes a laterally extending slot for selectively receiving an orthodontic archwire. The archwire locking device of the invention is used for maintaining the archwire within the laterally extending archwire slot of the bracket. The locking device is selectively moveable between a first locked position and a second unlocked position.
    Type: Grant
    Filed: December 16, 1997
    Date of Patent: March 28, 2000
    Inventor: Lawrence Hermann
  • Patent number: 6042374
    Abstract: A self-ligating orthodontic bracket comprised of a ligating member containing a coil spring segment for extending the ligating member over an archwire or retainer wire and over one or more tie wings to secure the archwire or retainer wire in the bottom of a slot in the bracket. The ligating member containing the coil spring may have ends that are engaged in opposing mesially-distally extending bores in one side of the bracket body, with the ligating member being engaged with one or more tie wings on an opposite side of the bracket body. Alternatively, the ligating member may form a closed loop with the ligating member engaged under both occlusally-projecting and gingivally-projecting tie wings or engaged under one or more tie wings on one side of the bracket body and passing through a mesially-distally extending bore on the opposite side of the bracket body.
    Type: Grant
    Filed: January 14, 1998
    Date of Patent: March 28, 2000
    Assignee: Ormco Corporation
    Inventors: Farrokh Farzin-Nia, Rohit C. L. Sachdeva, Thomas V. Selkee
  • Patent number: 5971753
    Abstract: An orthodontic bracket having an archwire slot includes a arc-shaped leaf spring capable of exerting a lateral force onto an archwire inserted into the archwire slot. The leaf spring is secured to a structure of said bracket at positions spaced along the slot. The bracket may have a slider plate to close the slot to avoid ligatures. In another embodiment the structure comprises an undercut holding the archwire in a position defined by the pressure exerted by the leaf spring. A bent slider may be interposed between said leaf spring and the archwire.
    Type: Grant
    Filed: January 13, 1999
    Date of Patent: October 26, 1999
    Inventor: Wolfgang Heiser
  • Patent number: 5967773
    Abstract: A low-profile orthodontic assembly comprising a bracket having a base surface and a top surface, the base surface for mounting to a tooth; at least two pairs of spaced-apart wings, the pairs in mutual faced-apart arrangement, extending upward from the bracket, each wing terminated by a distal end spaced-above the top surface; the distal ends of each the pair of wings joined together by a cross-member to form a passageway thereunder, above the bracket top surface and between the pair of wings; each the pair of wings positioned on opposite sides of a slot formed in the bracket to receive therein an archwire passing along the bracket; and, a cap for assembly with the bracket to cover a portion of the slot including a pair of springy, flexible tongues extending from opposite ends thereof for insertion down into the passageways to spring upward against the cross-members and retain the cap over the archwire with minimal contact therebetween.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: October 19, 1999
    Assignee: Orthodontic Design & Production
    Inventors: Patrick Roman, Richard Bryant
  • Patent number: 5931668
    Abstract: A ligature for securing an orthodontic bracket to an orthodontic archwire is formed from nylon and comprises a thin, elongate member having sufficient tensile strength to withstand orthodontic forces. A locking member receives the ligature therethrough and prevents disengagement of the ligature from an orthodontic bracket and an orthodontic archwire following installation. In one embodiment the ligature has locking teeth at one end and a locking member at the other end for cooperation with the locking teeth to prevent disengagement of the ligature. In another embodiment the ligature has locking teeth at both ends which engage one another and a locking tube to prevent disengagement of the ligature. In another embodiment the locking member is initially open and is closable to secure the ligature therein, thereby preventing disengagement of the ligature from an orthodontic bracket and an orthodontic archwire following installation.
    Type: Grant
    Filed: March 26, 1998
    Date of Patent: August 3, 1999
    Inventor: John W. Birkel
  • Patent number: 5906486
    Abstract: An orthodontic bracket comprises a spring ligating member comprising a thin flat metal strip that embraces the bracket body and is moved thereon between slot closed and open positions. At least the free end part of the spring member labial arm portion that closes the slot is of smaller width in the mesial distal direction than the arch wire slot gingival surface which is provided with a recess of smaller mesial distal width so that it is closed at its mesial and distal ends. The free end part of the labial arm portion extends into the recess to protect the spring member against excessive movement in the labial direction, while the arch wire slot gingival surfaces at the closed mesial and distal ends of the recess are engagable by an arch wire in the slot for application of maximum torque moment from the arch wire to the bracket.
    Type: Grant
    Filed: May 7, 1998
    Date of Patent: May 25, 1999
    Inventor: G. Herbert Hanson
  • Patent number: 5890893
    Abstract: An orthodontic bracket having an archwire slot and including a pressure spring capable of exerting a lateral force onto an archwire inserted into the archwire slot, said force pressing the archwire into abutment to a lateral slot wall thereby reducing the clearance of the archwire within the slot.
    Type: Grant
    Filed: February 26, 1998
    Date of Patent: April 6, 1999
    Inventor: Wolfgang Heiser
  • Patent number: 5885074
    Abstract: A ligature for an orthodontic appliance comprising a coil spring hoop of helically wound metal strip or wire or a wave spring hoop of wave wound metal strip or wire, preferably of shape memory metal. Such a metal ligature is simpler and more convenient to use than wire ties and has a life considerably longer than the elastomeric ligatures currently in use; because of this extended life they can be permanently attached to a bracket body to provide a self-ligating bracket. A coil wound ligature has the form of a hoop and is attached to the bracket body via a U-shaped core member threaded through part of the hoop and having its ends fastened to the bracket body. The ligature may have the form of a loop having its ends inserted in respective bores in the bracket body.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: March 23, 1999
    Inventor: Eric H. Hanson
  • Patent number: 5738513
    Abstract: An archwire locking device for an orthodontic bracket system is provided. The system includes a series of conventional edgewise brackets which engage the teeth of a patient by means of an adhesive which bonds the bracket to the tooth. Each bracket includes a laterally extending slot for selectively receiving an orthodontic archwire. The archwire locking device of the invention is used for maintaining the archwire within the laterally extending archwire slot of the bracket. The locking device is selectively moveable between a first locked position and a second unlocked position.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: April 14, 1998
    Inventor: Lawrence Hermann
  • Patent number: 5630715
    Abstract: A twin edgewise orthodontic bracket having an engagement mechanism for retaining an archwire, comprising a base having a pair of tie wing sets with an archwire slot and a slidable locking shutter or clip which in closed position retains the archwire in the archwire slot without the need for an elastic ligature and in open position allows placement and removal of the archwire.
    Type: Grant
    Filed: February 21, 1995
    Date of Patent: May 20, 1997
    Inventor: John C. Voudouris
  • Patent number: 5618176
    Abstract: An orthodontic bracket and ligature are provided in which the bracket, in the preferred embodiment, includes a cylindrical post, spaced from a bracket base to extend horizontally parallel thereto, and having an archwire slot therein. A spring material ligature band, naturally coiled and secured to a plastic installation strip, is pulled around the post of the bracket until a hooked trailing terminal end of the band catches on the bracket, pulling it loose from the strip, and allowing it to snap around the post to hold and confine the archwire in the slot. Different width ligatures seat to different positions on the post to allow the wire to be held to selected tightnesses in the slot by selection of the ligature.
    Type: Grant
    Filed: June 12, 1995
    Date of Patent: April 8, 1997
    Assignee: Ormco Corporation
    Inventors: Craig A. Andreiko, Mark A. Payne
  • Patent number: 5586882
    Abstract: Self-ligating orthodontic brackets comprise a spring ligating member of U-shape with converging arms movable on the bracket body between slot open and closed positions; in the latter position the spring retains an arch wire in the slot and urges the bracket and wire to their optimum relative positions. The ligating member is of a superelastic shape recovery metal alloy, preferably of thickness from 0.20 mm (0.008 in) to 0.25 mm (0.010 in), with rounded edges. At least the lingual portion of the member to be stiffer than the remainder; at least a part of the occlusal portion can also be stiffer. Alternatively, or in addition, the bracket body has a large mesial distal extending bore between and spaced from the bracket occlusal, lingual and labial surfaces and the arch wire slot occlusal surface. The large bore accepts attachment members used for attachment of a range of auxiliaries, such as hooks and traction springs.
    Type: Grant
    Filed: July 12, 1994
    Date of Patent: December 24, 1996
    Inventor: G. Herbert Hanson
  • Patent number: 5540586
    Abstract: A reinforced elastomeric non-hoop ligature comprises a thin flat body of the elastomeric material having incorporated therein a thin flat rigid insert of gingival-occlusal dimension greater than the corresponding dimension of the arch-wire receiving slot of the orthodontic bracket with which it is employed. The ligature body has holes or slots through which ligature retaining projections of the bracket body protrude, and when mounted on the bracket the rigid member straddles the bracket slot mouth. A reinforced hoop ligature comprises a torus of the elastomeric material with two diametrically opposed rigid inserts of gingival-occlusal dimension sufficient to straddle the bracket slot.
    Type: Grant
    Filed: October 6, 1994
    Date of Patent: July 30, 1996
    Inventor: G. Herbert Hanson
  • Patent number: 5470228
    Abstract: An improved edgewise orthodontic bracket is disclosed. In one embodiment, a bracket (10) comprises a single pair of opposing T-shaped tie wings (12, 14) which define an archwire slot (18) therebetween. Notches (20) are provided on each of the mesial and distal sides of the center leg (28) of each T-shaped tie wing (12, 14) for selectively receiving a ligating device. The notches (20) are defined in the gingival/occlusal edges of the tie wings (12, 14) and comprise sloped portions (24) that extend labially towards the archwire slot (18). Convex sidewall portions (42) and convex floor portions (44) are provided in the archwire slot (18) adjacent to the notches (20). An auxiliary slot (70) may be centrally disposed under the center legs (28) of the opposing T-shaped tie wings (12, 14). Alternatively, twin auxiliary slots (80) may be disposed under the convex archwire slot floor portions (44).
    Type: Grant
    Filed: May 12, 1993
    Date of Patent: November 28, 1995
    Assignee: RMO, Inc.
    Inventors: Steve A. Franseen, Jeffrey A. Peterson
  • Patent number: 5466151
    Abstract: A self-locking orthodontic bracket includes a supporting base and transversely spaced tying lugs interrupted by a transverse archwire slot. A closure mounted on the bracket includes a movable cover slidably overlapping an anterior surface across the bracket. The closure is supported by sliding guides that engage opposed side surfaces of the tying lugs. A transverse flat spring is recessed within the fixed wall to selectively engage indented areas on the posterior surface of the cover and serve as a detent. The detent selectively positions the cover in an open or closed position relative to the archwire slot. The brackets are preferably installed in two sets for attachment to the upper and lower teeth with the covers of both sets being movable to their open positions in common inferior directions. This facilitates visualization of the open archwire slot and adjacent bracket surfaces by attending professionals.
    Type: Grant
    Filed: June 28, 1994
    Date of Patent: November 14, 1995
    Assignee: Damon Family Limited Partnership
    Inventor: Dwight H. Damon
  • Patent number: 5439378
    Abstract: A self-locking orthodontic bracket includes a base for attachment to a tooth or tooth band. Transversely spaced tying lugs project from the base and include opposed extensions for orthodontic attachment purposes. The tying lugs present an anterior surface interrupted by an archwire slot. A closure mounted on the bracket includes a movable cover slidably engaging the anterior surface of the bracket. The cover spans the full width of the tying lugs and has a perpendicular width greater than the width of the archwire slot across the anterior surface. The closure is supported on the bracket by a pair of guides that slidably engage opposed side surfaces of the tying lugs for opening and closing the cover. The closure can also be designed to complement the archwire slot structure between the lugs, forming a complete tube encircling the archwire across the full width of the bracket when the cover is in its closed position.
    Type: Grant
    Filed: October 20, 1993
    Date of Patent: August 8, 1995
    Assignee: Damon Family Limited Partnership
    Inventor: Dwight H. Damon
  • Patent number: 5429500
    Abstract: A self-locking orthodontic bracket includes a base for attachment to a tooth or tooth band. Transversely spaced tying lugs project from the base and include opposed extensions for orthodontic attachment purposes. The tying lugs present an anterior surface interrupted by an archwire slot. A closure mounted on the bracket includes a movable cover slidably engaging the anterior surface of the bracket. The cover spans the full width of the tying lugs and has a perpendicular width greater than the width of the archwire slot across the anterior surface. The closure is supported on the bracket by a pair of guides that slidably engage opposed side surfaces of the tying lugs for opening and closing the cover. The closure can also be designed to complement the archwire slot structure between the lugs, forming a complete tube encircling the archwire across the full width of the bracket when the cover is in its closed position.
    Type: Grant
    Filed: October 20, 1993
    Date of Patent: July 4, 1995
    Assignee: Damon Family Limited Partnership
    Inventor: Dwight H. Damon
  • Patent number: 5356288
    Abstract: This invention relates to a novel bracket assembly for producing tooth movement in the treatment of dental malocclusions. A dual bracket system includes a primary and secondary bracket. An archwire is received in the secondary bracket. The primary bracket is attached to the tooth and the secondary bracket engages the primary bracket, thereby holding the secondary bracket and the archwire in place. Various configurations of the secondary bracket can be used with the primary bracket for producing desired tooth movements. A novel pin and ligature assembly can be used with the bracket assembly or a conventional bracket.
    Type: Grant
    Filed: December 7, 1992
    Date of Patent: October 18, 1994
    Inventor: Howard Cohen
  • Patent number: 5275557
    Abstract: A self-locking orthodontic bracket includes a base for attachment to a tooth or tooth band. Transversely spaced tying lugs are fixed to the base and include opposed extensions for orthodontic attachment purposes. The tying lugs present an anterior or front surface interrupted by a transverse archwire slot. A closure mounted on the bracket includes a movable cover slidably engaging the anterior surface of the bracket. The cover spans the full width of the tying lugs and has a perpendicular width greater than the width of the archwire slot across the anterior surface. The closure is supported on the bracket by a pair of guides that slidably engage opposed side surfaces of the tying lugs for opening and closing the cover. The closure can also be designed to complement the archwire slot structure between the lugs, forming a complete tube encircling the archwire across the full width of the bracket when the cover is in its closed position.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: January 4, 1994
    Inventor: Dwight H. Damon
  • Patent number: 4712999
    Abstract: An orthodontic bracket with self-ligating features is described. A cover plate is rotatably attached to the bracket base. Turning of the cover plate to the open position provides access to an archwire slot. After archwire placement, returning of the cover plate to its closed position achieves various degrees of play and seating depending on archwire size and cover plate configuration. The over plate promotes cleanliness and provides cosmetic advantages.
    Type: Grant
    Filed: September 10, 1986
    Date of Patent: December 15, 1987
    Inventor: Farel Rosenberg
  • Patent number: 4698017
    Abstract: The invention provides a new orthodontic bracket consisting of a bracket body having a mesio-distal extending arch wire receiving slot that opens to the labial surface. A latch member of "comma" transverse cross-section is accommodated in a recess in the body, being pivoted thereto by two spaced pivot pins passing through the latch member body portion, while the latch member tail portion moves between a closed position in which it closes the arch wire slot to retain an arch wire therein, and an open position in which the arch wire can be inserted in and removed from the slot. A load spring for applying corrective forces to the arch wire is accommodated within the body to the lingual side of the slot and is a thin bowed sheet spring convex toward the latch so that it urges the arch wire toward the latch lingual surface, the gingival part of which is inclined lingually for cooperation with the arch wire in controlling the movements of the bracket on the arch wire.
    Type: Grant
    Filed: December 10, 1986
    Date of Patent: October 6, 1987
    Inventor: Gustaf H. Hanson
  • Patent number: 4627816
    Abstract: The wire of an orthodontic appliance is attached at either end to a tooth by means of a lock secured to a band passed around the tooth and having a U-shaped recess into which a retaining spring is set so that when the latch holding the wire is inserted, the ends of the spring catch in notches on the latch thereby affording secure attachment and easy removal and replacement of the wire.
    Type: Grant
    Filed: May 16, 1985
    Date of Patent: December 9, 1986
    Inventor: Hans Gunzel
  • Patent number: 4561844
    Abstract: An improved orthodontic bracket for mounting on the inside surface or lingual of a tooth having an upwardly opening longitudinal channel for receiving an arch wire therein. The bracket includes a one-piece body having a locking groove formed in a front wall. A locking pin is rotatably mounted in a key-hole shaped opening formed in the body and is removable therefrom for replacement if it becomes damaged. The locking pin has a locking plate at one end of a shaft which is engageable in the locking groove of the body wall to secure an arch wire in the channel. A locking tab is mounted on the other end of the shaft and moves along a ramped surface formed in a recess for securing the locking plate in the locking groove. Rotation of the locking pin 180.degree. moves the locking plate between an arch wire retaining or locked position and an arch wire receiving or unlocked position. Rotation of the pin 90.degree.
    Type: Grant
    Filed: October 9, 1984
    Date of Patent: December 31, 1985
    Inventor: Lyn V. Bates
  • Patent number: 4443189
    Abstract: A multi-purpose orthodontic bracket comprises two interfitting cast parts, a body and a slider, uniquely configured to secure an arch wire to the lingual side of a tooth. The body has an arch wire slot oriented for insertion of an arch wire in a direction normal to the occlusal plane. The slider has a sliding portion slidably received in a channel extending transversely of the arch wire slot in the base of the body, and a closure member having a free end positioned to span the slot when closed. The channel is acutely angled from the depthwise plane or insertion direction of the slot. The closure member of the slider is positioned to move through such plane at an obtuse angle to it so that, during closure, its free end can either push the arch wire down into the slot or clamp it against a shoulder of the body alongside the slot.
    Type: Grant
    Filed: October 15, 1982
    Date of Patent: April 17, 1984
    Inventor: Alexander J. Wildman
  • Patent number: 4355975
    Abstract: The present invention relates to an orthodontic appliance for the treatment of dental malocclusion. Brackets of the present invention, used for securing the orthodontic wire, are all bonded to the internal sides of the teeth, that is, the lingual or palatal side. The orthodontic appliance comprises a plate bonded to a tooth, which plate is connected to the main body of the bracket. The covering orthodontic cap for fixing the wire is connected to the main body of the bracket. The cap can be removed from the bracket since it is fixed and connected thereto with a connecting part and elastic connecting device. The bracket or the cap is provided with a shearing groove that prevents the caps from sliding off and provides for locking and removal of the cap by simple operations.
    Type: Grant
    Filed: December 15, 1980
    Date of Patent: October 26, 1982
    Inventor: Kinya Fujita
  • Patent number: 4217686
    Abstract: The disclosure is directed to an orthodontic O-ring assembly which comprises a plurality of orthodontic O-rings integrally molded to a core which can be readily wrapped about an orthodontist's hand and the respective O-rings being individually dispensed by a ligator. The ligator comprises a tool having relatively moveable jaws which are sized so as to be received within the internal diameter of the O-ring in the closed position and thereafter moved to an open or expanded position to effect the stretching of the O-ring to be dispensed, thereby causing the O-ring to separate from its core at a frangible point. In a modified form of the invention, the ligator may be provided with a lock to maintain the ligator in the open jaw position.
    Type: Grant
    Filed: September 19, 1977
    Date of Patent: August 19, 1980
    Inventor: William B. Dragan
  • Patent number: 4193195
    Abstract: An orthodontic appliance to be used in a straight-wire technique setup as an auxiliary for applying closing forces between spaced teeth, wherein the appliance is mounted on a bracket attached to a band or pad. The appliance includes a base attachable to the bracket and an arm extending from the base and terminating in a hook for the attachment thereto of a force transmission member, such as an elastic. The appliance is attached to the bracket so that it is removable from the bracket after the use of the appliance has been completed and while the bracket remains mounted on a tooth.
    Type: Grant
    Filed: July 20, 1978
    Date of Patent: March 18, 1980
    Assignee: American Orthodontics Corporation
    Inventors: Daniel A. Merkel, John E. Viglietti, William P. Gagin
  • Patent number: 4180912
    Abstract: An orthodontic appliance for covering the outer surfaces of a light wire bracket and/or for securing an archwire thereto, which includes a body of tooth colored plastic material having means for detachably securing the appliance to a bracket, and being structured to substantially cover the faces of the bracket so that none are visible from the labial side.
    Type: Grant
    Filed: September 22, 1978
    Date of Patent: January 1, 1980
    Inventor: Peter C. Kesling
  • Patent number: 4178687
    Abstract: A clamp, particularly suitable for orthodontia, comprises a threaded screw member and a threaded nut member which is threadably engageable therewith. The screw member has a notch thereacross to receive a wire therethrough, the notch being directed generally towards one end of the thread on the screw. The notch opens on a surface of the screw for accepting a wire and has a first portion adjacent the opening which is defined by substantially parallel opposing walls, and has a second bottom portion which is adjacent the first portion and remote from the opening, the second bottom portion being generally V- or U-shaped and defined by inclined walls which are directed toward each other and toward the bottom of the notch.
    Type: Grant
    Filed: February 28, 1977
    Date of Patent: December 18, 1979
    Inventor: Melvin Wallshein