MOUNTING APPARATUS FOR DYNAMICALLY LOADED STRUCTURAL JOINTS
1. A mounting structure apparatus, comprising:
- A first member having an aperture through a first surface and communicating with a counterbore in a second surface;
a second member having a blind bore coaxial with said first member aperture;
an insert engageable with said counter bore, anda fastener insertable into said first member aperture and interactive with said second member blind bore to join said first member to said second member.
A mounting structure apparatus for dynamically loaded structure joints is disclosed. The apparatus includes a first member having an aperture through a first surface and communicating with a counterbore in a second surface. A second member is included having a blind bore coaxial with the first member aperture. An insert is engageable with the counter bore, and a fastener is disclosed insertable into the first member aperture and interactive with the second member to join the first member to the second member.
- 1. A mounting structure apparatus, comprising:
A first member having an aperture through a first surface and communicating with a counterbore in a second surface; a second member having a blind bore coaxial with said first member aperture; an insert engageable with said counter bore, and a fastener insertable into said first member aperture and interactive with said second member blind bore to join said first member to said second member.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
This disclosure was made in part with Government support by The United States Department of the Army. The Government has certain rights in the disclosure.
This disclosure relates to improved mounting structures for dynamically loaded structural joints. The mounting structure allows shear strength and tensile strength of a joint to be independently tuned by varying sizes of an engaged counter bore and a fastener.
Existing fasteners are limited in creating a joint with improved shear and tensile strength. Traditional joints consisting of a bolt threaded into a nut are limited in the amount of energy they can absorb prior to failure. This is especially important in situations with dynamically loaded structural joints. Dynamically loaded structural joints, such as those formed when jointing armor plating, are subjected to shear and tensile forces. Existing fasteners can also result in a “secondary projectile” when subjected to shear forces that overcome the fastener strength. It is important to be able to accommodate these forces in armored vehicles which may be subjected to blast forces that may overcome existing fasteners.
Improvements to such joints are given in the several embodiments disclosed. In one embodiment, one piece of a structure may be attached to another piece of a structure with a bolt and an insert that is mechanically loaded as a result of translational movement of the two pieces. The insert may be threaded into the main piece of structure, and the insert may have internal threads for attachment, and a shoulder feature that sits on the surface of the main structure. The mating piece of the structure has a counterbore that fits over the shoulder of the insert and transfers load when translation occurs between the two structures.
All figures and examples herein are intended to be non-limiting; they are mere exemplary iterations and/or embodiments of the claims appended to the end of this description. Modifications to structure, materials, the order of steps in procedures, etc., are contemplated.
Referring now to the drawings, and particularly to
Any of the described mounting structures may be used for joining dynamically loaded structures. One piece of structure is attached to another piece of structure with a bolt and an insert that is mechanically loaded as a result of translational movement of the two pieces of structure. The insert may be threaded or otherwise joined, such as a physical/chemical bonding, or a press fit, or a friction weld) into the main piece of structure, and, may have internal threads for attachment and a shoulder feature that sits on the surface of the one of the structures. The other piece of the structure (mating structure) has a counterbore that fits over the shoulder of the insert that transfers load when translation occurs between the two structures (members) to be joined. A fastener, such as a bolt, threads into the internal thread of the insert holding two pieces of structure together. In one embodiment, the configuration of the counterbore depth is tolerance such that the clamp load provided by the bolt clamps the two members together. The counterbore may be oblong or circular. An oblong counterbore allows for the members to be joined at an angle and will load the fastener and counterbore in three directions and the fastener in one direction. The mounting structures as described may be tuned as one might tune a shear pin, so that it could be constructed to take certain forces without failure but fail if those forces are exceeded.
The tolerances of the fastener, insert major diameter and counterbore diameter can be utilized to adjust the load sharing between the fastener (bolt) and the insert. The fastener can be utilized to adjust the load sharing between the fastener and the insert. The insert can be comprised of different materials dependant on the properties required. To maximize the energy the joint can transmit, a fastener with superb elongation and energy to failure properties may be selected.
The mounting structures as described may be suited for structural joints and may be selected for use in the application of under armor to eliminate the need for a puck on the inside face of the structure. The insert is threaded into the structure and can be replaced without reworking the base structure. The mounting apparatus as described can be utilized to reduce weight by allowing for the use of smaller fasteners (bolts). In additional the shear strength and tensile strength of the joint can be tuned independently by varying the sizes of the engaged counterbore and the fastener (bolt). Joints may be designed to have different shear strength in different directions by shaping of the counterbore.
Although the steps of the above-described processes have been exemplified as occurring in a certain sequence, such processes could be practiced with the steps performed in a different order. It should also be understood that certain steps could be performed simultaneously, that other steps could be added, or that certain steps could be omitted. In other words, the descriptions of the processes are provided for the purpose of illustration, and should not limit the claimed invention.
Accordingly, it is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent upon reading the disclosure. The scope of the invention should be determined with reference to the appended claims along with the full scope of equivalents. It is intended that future developments will occur, and that embodiments of the disclosed systems and methods will incorporate and be incorporated with such future developments.
Use of singular articles such as “a,” “the,” “said” together with an element means one or more of the element unless a claim expressly recites to the contrary.