Hopper fed tee-nut having counterbore with nylon lock

[0001] The invention is in the field of tee-nuts having locks or locking rings to secure a threaded screw or bolt therein.

[0002] U.S. Pat. No. 5,904,461 to McKarge, Jr. discloses a locking tee-nut (T-nut) 10 for securely fastening a threaded element such as a threaded bolt to a structure. FIG. 1 is a front view of a prior art tee-nut illustrated in combination with a caster 50. The tee-nuts 10 are used to secure the frame of the caster to the substrate. The device includes a cylindrical nut body 20 with a threaded bore 22 extending therethrough. The bore 22 has at least one resilient locking ring 40, 42 mounted within an annular groove 25 provided on the inner surface of the bore. A radial flange 30 extends radially from one end of the nut body and includes at least one securing tooth 32 extending therefrom toward the other end of the nut body. Reference numeral 21 denotes the outer surface of the body and reference numeral 28 is an annular lip. FIG. 2 is a cross-sectional view of the prior art tee-nut of FIG. 1.

[0003] The McKarge, Jr. tee-nut is not easily fed through a track delivery system due to the geometry of the teeth 32. It is, therefore, desirable to have a tee-nut which is reliably guided by a track and which includes the feature of a nylon locking ring for securing a stud which interengages the tee-nut.

[0004] Additionally, the tee-nut of McKarge has the disadvantage in that it may be dislodged from the substrate during assembly when a threaded member is inserted into the tee-nut because of the location of the resilient locking ring 40. In other words as the bolt 1 as illustrated in FIG. 1 is inserted into the tee-nut the teeth 32 may come loose by the force of the bolt pushing the locking ring 40 and the entire tee-nut out of the substrate 2. Additionally, the McKarge tee-nut has the disadvantage of short teeth or prongs 32 which are easily extracted from the substrate 2. In other words the teeth or prongs 32 are relatively short in relation to the locking ring 40. The other locking ring 42 does not solve the problem of pushing the tee-nut out of the substrate because the locking ring 40 is engaged by the bolt 1 before the bolt ever reaches the locking ring 42. Additionally, locking ring 42 also does not solve the problem even if locking ring 40 is not used because the teeth of McKarge are not long enough to prevent extraction of the tee-nut from the substrate. The locking ring 42 of McKarge is about the same length as the teeth 32 of McKarge.

[0005] The tee-nut of McKarge will require an external force to hold the tee-nut in engagement with the substrate.

[0006] These and other problems are solved by the instant invention as set forth hereinbelow.

[0007] A tee-nut for use in combination with a track is disclosed and claimed. The track comprises an upper guide and a lower guide. The upper guide is spaced apart relatively narrower than the lower guide.

[0008] The tee nut comprises a flange which includes an upper portion and a lower portion. The upper and lower portions of the tee nut slide within the guides. The tee nut includes a shank or barrel extending perpendicularly from the upper portion of the flange and a head extending perpendicularly from the lower portion of the flange. The flange includes four elongated teeth which extend perpendicularly from the flange and which are inserted deeply into a wooden substrate. A passageway extends through the barrel, flange and head. The passageway includes a stepped bore, a cavity, and female threads within the bore for interengagement with a stud. The passageway includes a first-counterbored entranceway for reception of a threaded stud. The first counterbore accommodates misalignment of the threaded stud with respect to the entranceway to the passageway so as to guide the threaded stud into the female threaded portion of the passageway. A locking ring resides in the cavity in the passageway.

[0009] The cavity is formed by a second counterbore at an end opposite the first counterbore and is enclosed by a lip which is deformed so as to assist in retaining a thin nylon locking ring in the bore or passageway of the tee-nut. The nylon locking ring is thin relative to the length of the four elongated teeth so as to ensure that the tee-nut will not be extricated from (pushed out of) the wooden substrate when a stud interengages the females threads of the passageway of the tee-nut. When a bolt or other threaded member is inserted into the first counterbore and is threaded into the female threaded portion of the passageway, it should be noted that the nylon locking ring is located relatively far from the entrance to the barrel shaped portion of the tee-nut. Thus, as the bolt is threaded into the tee-nut it interengages the nylon locking ring and tends to push the entire tee nut in the direction of travel of the bolt. However, since the nylon locking ring is not very thick or deep the prongs or teeth of the tee nut cannot escape (longitudinally, i.e., in the direction of travel of the bolt) from the substrate thus enabling the bolt to be completely threaded into the tee-nut resulting in a secure fastening device. It will be noticed that the nylon locking ring in the longitudinal or axial direction is not very thick compared to the length of the teeth of tee-nut. This means that the prongs or teeth remain embedded in the member or bolt to completely engage the nylon locking ring. To the extent a gap is created during coupling of a threaded member with the tee nut, the gap is closed and the tee-nut is drawn back into the substrate as the threaded member is screwed further into the tee nut.

[0010] The bore or passageway of the tee-nut extends completely through the tee-nut.

[0011] The head resides between the lower guide and the teeth reside between the upper guide and the tee nuts are thus guided by the track.

[0012] The stud interengages the locking ring which is preferably made of nylon. Since the nylon is relatively inelastic the stud cannot be loosened from the tee-nut as a result of vibration and similar forces and thus ensures a secure fastener.

[0013] A method of manufacturing a tee-nut is disclosed comprising the steps of: cold heading steel to form a flange having a solid barrel portion and a solid head portion; cold heading a bore through the solid barrel portion and the solid head portion; cold heading and forming a first counterbore in the bore of the barrel portion; cold heading and forming a second counterbore in the head portion for receiving a nylon locking ring; threading a portion of the bore; inserting the nylon locking ring into the second counter bore; crimping the nylon locking ring in place. The step of zinc plating may be added to the process. Additionally, the step of crimping the nylon locking ring may be performed by crimping the lip portion. The step of forming prongs or teeth may be added to the process as well.

[0014] Accordingly it is an object of the instant invention to provide a tee-nut which does not separate from the substrate in which it is lodged upon the entry of a threaded stud within the tee-nut.

[0015] It is a further object of the instant invention to provide a tee-nut which includes prongs or teeth which extend from a flange in combination with a nylon locking ring positioned such that the tee-nut will not be forcefully separated from a substrate in which it is embedded.

[0016] It is a further object of the instant invention to provide a hopper fed tee nut having a first counterbore and a nylon lock.

[0017] It is a further object of the present invention to provide a tee-nut having an enlarged head portion and a nylon lock within the enlarged head portion.

[0018] It is a further object of the present invention to provide a tee-nut having a nylon lock residing within a second counterbore located within the enlarged head.

[0019] It is a further object of the invention to provide a tee-nut having a head on one side of the flange with the head accommodating a nylon locking ring which is relatively thin.

[0020] It is a further object of the invention to provide a tee-nut having relatively long teeth or prongs extending from a flange and wherein the length of the teeth or prongs exceeds the axial length (thickness) of the nylon locking ring.

[0021] These and other objects will be best understood when reference is made to the Brief Description Of The Drawings and Description Of The Invention which follow hereinbelow.

[0036] The drawings will be better understood when reference is made to the Description of the Invention and Claims which follow hereinbelow.

[0037] FIG. 1 is a front view of a prior art tee-nut 1 illustrated in combination with a caster and was described above in connection with the Background Of The Invention above. FIG. 2 is a cross-sectional view of the prior art tee nut of FIG. 1 with the Background Of The Invention above.

[0038] FIG. 3 is a bottom-side perspective view 300 of the hopper fed tee-nut of the instant invention. The hopper fed tee-nut includes head 320 which is used to guide the tee-nut in a feed track which leads from a hopper (not shown). Head 320 resides within a slot in the hopper feed. Locking ring 309 resides within a lip 320 to the head 302. Head 302 extends perpendicularly away from the bottom side 301A of flange 301. The tee-nut includes teeth 304, 305, 306, and 307 which extend perpendicularly in a direction opposite of the head 302. Teeth 304, 305, 306 and 307 are deformed and extend downwardly away from the flange 301. Reference numeral 301B is used to denote the top side of flange 301B and shank 303 extends perpendicularly away from the top side 301B of the flange 301.

[0039] Generally the material of construction of the tee nut is C1006 to C1010 carbon steel with a zinc plate finish. The locking ring 309 is preferably nylon but may be made of any suitable hard plastic capable of gripping exterior threads of a stud which non-elastically deform the suitable hard plastic.

[0040] FIG. 3A is a top side (gripping side) perspective view 300A of the hopper fed tee-nut of the instant invention. The tee-nut includes a passageway comprised of inner surfaces 309A, 308, 321 and 320. Surface 308 is a threaded surface which interengages corresponding threads 401A on stud 401. See, FIG. 4D which is a cross-sectional view 400D of the tee-nut interengaging a substrate made of wood 403 and coupled with a stud 401. Stud 401 secures two substrates such as those denoted by reference numerals 402 and 403 together. Reference numeral 309A is used to denote a cavity in which nylon locking ring 309 resides. However, the passageway through the tee nut includes the second entranceway 302 to the cavity 309A, the cavity 309A, the interior threaded portion 308 and the first counterbore or opening 321. The first counterbore 321 extends approximately 0.13 inches into the bore in the barrel portion of the tee-nut. The first counterbore enables alignment and coupling with a stud having exterior threads thereon.

[0041] Locking ring 309 is a nylon or other hard polymer which interengages threads 401A of stud 401 as illustrated in FIGS. 4D and 4E. As threads 401A enter the locking ring 309 deformation 309B of the ring 309 occurs and threads 401A interengage the locking ring 309 and prevent the extraction of the stud 401 from the tee-nut. Locking ring 309 prevents the stud 401 illustrated in FIG. 4D from becoming loose so that the wood substrate pieces 402 and 403 remain joined together.

[0042] FIG. 4 is a top side view 400 of the tee-nut and illustrates the bore or passageway 321, 308 and the top of the flange 301B. Inner walls 309A and 322 are not visible in FIG. 4. FIG. 4A is a side view 400A of the tee nut viewed from the perspective of line 4A-4A of FIG. 4. Teeth or prongs 304, 305, 306, and 307 are bent upwardly from flange 301, are formed therefrom, and are of the same thickness as the flange 301. One such flange thickness which may be used is 0.06 inches; however, different flange thicknesses may be used depending on the application of the tee nut and the loads on the parts or substrates secured thereby.

[0043] FIG. 4B is a cross-sectional view 400B of the invention taken along the line 4B-4B of FIG. 4. FIG. 4B illustrates the inner surfaces 321, 308, 309A and 322 which form a passageway which receives a threaded stud 401 illustrated in FIG. 4D. FIG. 4C is a side view of the tee nut as viewed along the line 4C-4C of FIG. 4.

[0044] FIG. 4D is a cross-sectional view 400D of the tee nut interengaging the first substrate 403 which may be wood or plywood coupled to a second substrate 402 which also may be wood or plywood. A stud 401 is used which has threads 401A which interengage reciprocal threads 308 of the tee nut. As stud 401 is threaded into the reciprocal threads 308 of the tee nut threads 401A interengage and deform nylon ring 309. Reference numeral 309B is used to denote the deformation of nylon ring 309 by threads 401A. See, FIG. 4E.

[0045] Nylon ring 309 is trapped in a cavity 309A of the head portion 302 of the tee nut. Specifically, nylon ring 309 is trapped in a space defined generally by inner annular wall 309A and lip 322. The nylon ring 309 is non-elastically deformed when a threaded stud is forcibly engaged therewith. Reference numeral 309B represents the deformation of the nylon ring 309. As the stud is forcibly rotated into and through a portion of the nylon ring 309, a helical path matching the helical geometry of the stud is formed within the nylon ring. Referring to FIG. 4B, nylon ring 309 is annularly shaped with an inner diametrical surface 309D which extends radially inwardly. The nylon ring is essentially shaped like a washer.

[0046] Threaded portion 308 of the passageway includes an inner diameter 308D which represents the diameter of the threaded bore at the mean diametrical extent of the threads. Inner diametrical surface 309D (inner diameter surface 309D) of the locking ring 309 extends radially inwardly further than the inner diameter 308D of the threaded portion 308 which results in threads 401A interengaging the locking ring 309. See, FIG. 4F. Since the nylon ring 309 is retained within the head portion 302 of the tee nut, stud 401 does not loosen with respect to the threads 308 as the nylon ring 309 and the stud cannot move.

[0047] FIG. 4D is a cross-sectional view 400D of the tee nut interconnecting first substrate 403 and second substrate 402 together. The shank or barrel 303 of the tee nut is press fit into a corresponding bore 405 in the first substrate 403. In one example the shank or barrel of the tee-nut is approximately 0.33 inches long. Alternatively, barrel 303 of the tee-nut may snugly fit into bore 405 or the tee-nut may even be inserted with a gap between the barrel 303 and the bore 405. Teeth 304, 306 are pressed into the first substrate 403 until the top 301B of the flange 301 of the tee-nut is flush with respect to the surface 403A of the first substrate 403. It will be noticed that the teeth 304, 306 of the tee-nut are relatively long and are shown in phantom in FIG. 4D as substantially engaging substrate 403. In one example the teeth are approximately 0.25 inches long. Therefore, as the stud 401A enters the passageway it interengages threads 308 which are female interior threads of the tee-nut. As the stud progresses through and in engagement with threads 308 it engages nylon locking ring 309 where it is met with some resistance as nylon locking ring is not threaded. In one example the nylon locking ring is approximately 0.10 inches thick. In one example the overall length of the tee-nut is approximately 0.50 inches. The thickness of the nylon locking ring is relatively small in comparison to the length of the teeth so as to ensure that the teeth remain engaged with a wooden substrate in which the teeth of the tee-nut are embedded.

[0048] Referring to FIG. 4D, as bolt 401 interengages nylon ring 309 it tends to push the teeth 304, 306 (and the other teeth not shown in FIG. 4D) out of engagement with the wooden substrate 403. However, since the thickness of the nylon ring is relatively thin (small) as compared to the length of the teeth 304, 306, the threads 401A of the stud forcibly interengage the nylon ring 309 and inelastically deforms nylon ring 309 so as to secure the stud 401 to the nylon ring 309 and hence to the tee nut. While the threads 401A of the stud are interengaging the nylon ring 309 the top surface 301B of the flange of the tee-nut may separate slightly from the surface 403A of the wooden substrate creating a temporary gap. However, during this time the tee-nut will not rotate because the teeth are long enough to prohibit the rotation and the thickness of the nylon ring is approximately 0.10 inches. As the stud 401 is completely tightened the tee-nut and the teeth of the tee-nut are drawn completely back into the wooden substrate into the position indicated in FIG. 4D.

[0049] The passageway through the tee-nut includes a relatively larger diametrical region 321 than the mean diameter of the threaded region 308 to facilitate entry of the stud 401 into the threaded region. A bore 404 through the second substrate (wood/plywood) 402 permits passage of the stud 401 therethrough. An enlarged head portion (not numbered) of the stud engages the surface of the second substrate 402. In this way, the stud 401 engages the wooden substrate 402 securing it forcibly against the wooden substrate 403 such that there is no movement therebetween. Nylon locking ring 309 locks stud 401 with respect to the tee nut and stud 401 cannot be loosened with respect to threads 308.

[0050] The cavity 309 is formed by a second counterbore at an end opposite the first counterbore and is enclosed by a lip 320 which is deformed so as to assist in retaining the nylon locking ring in the bore or passageway of the tee-nut. When a bolt 401 or other threaded member is inserted into the first counterbore and is threaded into the female threaded portion 308 of the passageway, it should be noted that the nylon locking ring 309 is located relatively far from the entrance to the barrel shaped portion of the tee-nut. Thus, as the bolt 401 is threaded into the tee-nut it interengages the nylon locking ring and tends to push the entire tee nut in the direction of travel of the bolt. However, since the nylon locking ring is not very thick or deep the prongs or teeth of the tee nut cannot escape (longitudinally, i.e., in the direction of travel of the bolt) from the substrate 403 thus enabling the bolt to be completely threaded into the tee-nut resulting in a secure fastening device. It will be noticed that the nylon locking ring in the longitudinal or axial direction is not very thick compared to the length of the teeth of tee-nut. The bore or passageway of the tee-nut extends completely through the tee-nut.

[0051] FIG. 4E is an enlargement 400E of a portion of FIG. 4D illustrating the stud interengaging the nylon ring. Reference numeral 309B is used to indicate the non-elastic deformation of the nylon ring 309 so as to secure the stud 401 to the tee-nut.

[0052] FIG. 4F is a view 400F similar to FIG. 4E without the nylon locking ring 309 in the counterbore 309A. FIG. 4F illustrates the internal geometry of the cavity 309A which is formed by a second counterbore in the tee-nut. The second counterbore 430 is diametrically larger than the first counterbore in the tee-nut and is located within the head portion 302 of the tee-nut. A lip 322 is formed by mechanically bending the wall at the point of the second counterbore forming cavity 309A.

[0053] The track comprises an upper guide 501 and a lower guide 502. The upper guide is spaced apart relatively narrower than the lower guide. The tee nut comprises a flange 301 which includes an upper portion and a lower portion. The upper and lower portions of the tee nut slide within the guides. The tee nut includes a shank or barrel 303 extending perpendicularly from the upper portion 301B of the flange and a head 302 extending perpendicularly from the lower portion 301A of the flange. The flange includes four teeth 304, 305, 306, 307 and a passageway 321, 308, 309A, 322, through the flange. The passageway includes a first counter bore 321 located within barrel 303, a stepped bore portion or shoulder 321A, a female threaded portion 308, a cavity or annular wall 309A, and an exit wall portion 322. The female threaded portion 308 within the bore interengages stud 401.

[0054] The passageway includes a first counterbored entranceway 321 for reception of threaded stud 401. The counterbore 321 accommodates misalignment of the threaded stud 401 with respect to the entranceway to the passageway so as to guide the threaded stud 401 into alignment with the female threaded portion 308 of the passageway. Shoulder 321A reduces the diameter of the bore to that represented by reference numeral 308D, the mean diameter of the threaded portion 308 of the bore through the tee nut. A locking ring 309 resides in the cavity 309A in the passageway. The cavity 309A is formed by a second counterbore 430 at an end opposite the first counterbore, i.e., at the head portion 302 of the tee-nut and is enclosed by a lip 320 which is deformed so as to retain the nylon locking ring 309 in the bore or passageway of the tee-nut. The bore or passageway of the tee-nut extends completely through the tee-nut. Lip 320 is created by mechanically deforming wall 309W.

[0055] FIG. 5 is a perspective view 500 of the barrel portion 303 of the tee-nut guided within track 501. FIG. 5A is an end view 500A of the tee-nut illustrated within the track. The track includes upper guide 501 and lower guide 502 portions for routing head portion 302 of the tee nut within the lower guide portion 502 and for routing teeth 304, 305, 306 and 307 through the upper guide portion 501 of the track. The upper guide portion of the track 501 is necessarily narrower as the spacing between the teeth 304, 305 and 306, 307 is narrower than the outside diameter of the head portion 302 of the tee-nut.

[0056] A process for making the tee-nut of the invention is disclosed. See, FIG. 6, a schematic illustration 600 of the process steps for manufacturing the tee-nut of the instant invention. The steps of the process include: cold heading steel to form a flange having a solid barrel portion and a solid head portion, 601; cold heading a bore through the solid barrel portion and the solid head portion, 602; cold heading and forming a first counterbore in the bore of the barrel portion, 603; cold heading and forming a second counterbore in the bore of the head portion for receiving a nylon locking ring, 604; threading a portion of the bore, 605; forming prongs or teeth, 609; zinc plating the tee-nut, 608; inserting the nylon locking ring into the second counter bore, 606; and, crimping the nylon locking ring in place 607. Additionally, the step of crimping the nylon locking ring may be performed by crimping the lip portion. The steps set forth herein may be performed in different sequences as desired.

[0057] The second counterbore forms a shoulder 430 in the bore through the tee-nut. Cavity 309A is bounded by the second counterbore and it is this second counterbore which interengages the locking ring 309 and secures it in place along with lip 320. The instant invention includes a passageway having a bore therethrough with the first counterbore terminating in shoulder 321A and the second counterbore terminating in shoulder 430. The counterbores 321A, 430 enable stud 401 to be inserted as indicated in FIG. 4D and to retain the locking ring 309.

[0058] A list of reference numerals follows.

• [0059] 1—threaded element
• [0060] 2—structure such as a plate
• [0061] 10—tee-nut
• [0062] 20—nut body
• [0063] 21—outer surface of the nut body
• [0064] 22—bore
• [0065] 25—annular groove
• [0066] 28—annular lip
• [0067] 30—radial flange
• [0068] 32—securing teeth
• [0069] 40—locking ring
• [0070] 42—locking ring
• [0071] 50—caster
• [0072] 301—flange
• [0073] 301A—bottom side of flange
• [0074] 301B—top side of flange
• [0075] 302—head of tee-nut
• [0076] 303—shank
• [0077] 304—tooth
• [0078] 305—tooth
• [0079] 306—tooth
• [0080] 307—tooth
• [0081] 308—threaded surface of passageway
• [0082] 308D—thread diameter
• [0083] 309—nylon locking ring
• [0084] 309A—inner surface of passageway
• [0085] 309B—non-elastic deformation of the locking ring caused by the threads of the stud
• [0086] 309D—diameter of the inner surface of the locking ring 309
• [0087] 309W—wall thickness of the second counterbore
• [0088] 320—lip or opening
• [0089] 321—first counterbore, opening of passageway
• [0090] 321A—shoulder in bore
• [0091] 322—wall of passageway trapping ring 309
• [0092] 401—stud
• [0093] 401A—threads on stud 401
• [0094] 402—second substrate
• [0095] 403—first substrate
• [0096] 403A—surface of first substrate 403
• [0097] 404—bore in second substrate 402
• [0098] 405—bore in first substrate 403
• [0099] 430—second counterbore
• [0100] 501—upper portion of track
• [0101] 502—lower portion of track
• [0102] 601—cold heading steel to form a flange having a solid barrel portion and a solid head portion
• [0103] 602—cold heading a bore through the solid barrel portion and the solid head portion
• [0104] 603—cold heading and forming a first counterbore in the bore of the barrel portion
• [0105] 604—cold heading and forming a second counterbore in the head portion for receiving a nylon locking ring
• [0106] 605—threading a portion of the bore
• [0107] 606—inserting the nylon locking ring into the second counter bore
• [0108] 607—crimping the nylon locking ring in place
• [0109] 608—plating the tee-nut with zinc or other material
• [0110] 609—crimping the nylon locking ring may be performed by crimping the lip portion
• [0111] 610—pressing or forming teeth or prongs.

[0112] The dimensions given in the specification are by way of example only and may be changed without departing from the spirit and scope of the claims which follow hereinbelow. Those skilled in the art will readily recognize that the invention has been set forth by way of example only and that changes may be made to the invention which has been set forth herein with particularity without departing from the spirit and scope of the invention as set forth in the claims below. For instance, changes to the length of the teeth or prongs may be made. Additionally, changes to the thickness or the axial length of the nylon locking ring can be made without departing from the spirit and the scope of the invention as set forth in the claims below.