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US 6,672,811 B2Granted
Threaded insert for fasteners
AssigneeHi-Shear Corporation
InventorDennis Schultz
Life of this patent
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AssigneeHi-Shear Corporation
InventorDennis Schultz
Estimating the term…
A threaded insert for providing stronger threads to a parent material. The threaded insert includes a bushing portion having male threads on the external surface and female threads within an internal bore. The threaded insert also includes keys which lock the threaded insert into a threaded hole within the parent material. The keys are positioned within slots along the external surface of the bushing portion of the threaded insert. The slots include two substantially parallel walls which are substantially perpendicular to a bottom surface of the slots. A method for assembling the threaded insert reduces the tendency of the keys to be installed offset from the bottom surface of the slots.
A threaded insert, comprising:
A threaded insert, comprising:
A method of assembling a threaded insert, comprising:
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
From the US filing history. Foreign family members aren’t listed.
Threaded inserts, e.g. "rampa bolts": the external surface of the insert being threaded
With a member penetrating the screw-threaded surface of at least one part, e.g. a pin, a wedge, cotter-pin, screw: with a pin or staple parallel…
Thread lock: longitudinal key
Devices for fastening or securing constructional elements or machine parts together
Term ended 22 May 2022 (estimated)
1. Field of the Invention
This invention relates generally to threaded inserts, and more particularly to a threaded insert having keys which are positioned within 90° straight wall slots.
2. Description of the Related Art
From the above, it may be seen that the invention provides for a threaded insert having at least one key which is positioned within a slot having parallel walls that are perpendicular to the bottom surface of the slot. It may also be seen that the key has less tendency to broach into the slot within the bushing portion and that the threaded insert is configured for improved key driving compared to prior art threaded inserts. Additionally, it may be seen that the threaded insert of the invention can be manufactured more economically and with improved retention and alignment of the key compared to prior art threaded inserts. These and other aspects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings, which illustrate by way of example the features of the invention.
FIG. 1a is an elevation view, partly in cross section, depicting a prior art threaded insert.
FIG. 1b is a plan view of the prior art threaded insert of FIG. 1a taken from line 1b-1b in FIG. 1a.
As shown in the drawings, which are provided for purposes of illustration, but not by the way of limitation, the invention is embodied in a threaded insert which is used to provide strong, permanent threads in a relatively soft or ductile parent material. Referring to the drawings in which like reference numerals are used to designate like or corresponding elements among the figures, FIG. 2 depicts a threaded insert 20 of the present invention. The threaded insert 20 includes a bushing portion 22 having a substantially cylindrical shape with a first end 24, a second end 26 and a central bore 28 therethrough. A surface of the central bore 28 includes female threads 30 throughout the length of the bushing portion 22, while an external surface 32 of the bushing portion includes male threads 34 throughout the length of the bushing portion. The male threads 34 may be configured to mate with a threaded hole 36 (FIGS. 5a and 5b) in a parent material 38, such as a plate or casting, while the female threads 30 may be configured to mate with a male threaded fastener, such as a bolt or a stud (not shown). The threaded insert 20 also includes at least one key 40 for ensuring that the threaded insert does not rotate within the threaded hole in the parent material after installation into the parent material. Each of the keys 40 is positioned within a slot 42 which extends substantially longitudinally along the external surface 32 of the bushing portion 22. In one currently preferred embodiment, the threaded insert 20 includes four keys 40 which are positioned within four respective slots arranged approximately ninety degrees apart from each other about the circumference of the bushing portion 22.
Referring to FIGS. 3a and 3b, the key 40 includes a tang portion 44 and a locking portion 46 which may be formed from a single piece of material which is stronger than the parent material. The tang portion 44 may include a substantially longitudinal structure having a first end 47, a second end 49, a first face 48 and a second face 50. The first face 48 and the second face 50 of the tang portion 44 may be substantially parallel and include a curved profile with the first face forming an inside, concave curved surface and the second face forming an outside, convex curved surface. The tang portion 44 may also include a first side surface 52 and a second side surface 54. The first side surface 52 may be substantially perpendicular to the tangent along the first face 48 at the intersection of the first face and the first side surface. Similarly, the second side surface 54 may be substantially perpendicular to the tangent along the first face 48 at the intersection of the first face and the second side surface. The curved shape of the tang portion 44 may be created through manufacturing processes which are well known in the art, such as stamping.
The locking portion 46 of the key 40 may include a substantially longitudinal structure which is positioned adjacent to the tang portion 44. The locking portion 46 may include a first end 55, a second end 57 and a substantially triangular cross section. The triangular cross section may include a back face 56 and two angled faces 58. The second end 57 of the locking portion 46 may be positioned adjacent to the first end 47 of the tang portion 44 such that the tang portion and the locking portion are substantially longitudinally aligned. The back face 56 of the locking portion 46 may be substantially longitudinally aligned with an apex 60 of the first face 48 of the tang portion 44. The two angled faces 58 of the locking portion 46 may taper into the second face 50 of the tang portion 44 of the key 40, such as through an angled taper or a curved taper. The distance between the back face 56 and the intersection 62 between the two angled faces 58 is sufficient such that after installation of the key 40 into the slot 42 in the bushing portion 22 (FIGS. 4a, 4b and 4c), the intersection of the angled faces is positioned at a depth which is shallower than the inside diameter 72 of the male threads 34 on the external surface 32 of the bushing portion. In one currently preferred embodiment, the intersection 62 of the two angled faces 58 of the locking portion 46 may be positioned substantially flush with the outside diameter 64 of the male threads 34 on the external surface 32 of the bushing portion 22. In other currently preferred embodiments, the intersection 62 of the two angled faces 58 of the locking portion 46 may be positioned either above flush or below flush with the outside diameter 64 of the male threads 34 on the external surface 32 of the bushing portion 22. An end surface 66 at the first end 55 of the locking portion 46 may be substantially perpendicular to the back face 56 and the two angled faces 58.