Beam suspension system

• US 4,019,298 A
• Filed: 11/04/1974
• Issued: 04/26/1977
• Est. Priority Date: 07/18/1973
• Status: Expired due to Term

• Current Assignee: International Designs Ecological Products and Processes Incorporated
• Original Assignee: John J. Johnson IV
• Inventors: Johnson, John J. IV
• Primary Examiner(s): Ridgill, Jr., James L.
• Application Number:
  US05/520,478
• Time in Patent Office: 904 Days
• Field of Search: 403/49, 403/175, 403/381, 403/331, 29/150, 52/122, 52/660, 52/594, 52/646, 182/178, 182/179, 5/300
• US Class Current: 52/590.1
• CPC Class Codes: A47B 2230/0081 Mortise and tenon type joints with some general male and female joints
• CPC Class Codes: E04B 1/185 Connections not covered by E04B1/21 and E04B1/2403, e.g. connections between structural parts of different material
• CPC Class Codes: E04B 1/541 Joints substantially without separate connecting elements, e.g. jointing by inter-engagement
• CPC Class Codes: F16B 2200/30 Dovetail-like connections
• CPC Class Codes: F16B 5/0052 the interlocking key acting as a dovetail-type key
• CPC Class Codes: Y10T 403/30 Laterally related members connected by latch means, e.g. , scaffold connectors
• CPC Class Codes: Y10T 403/346 Additional rod held by encompassing means
• CPC Class Codes: Y10T 403/61 Side slide: elongated co-linear members

Abstract

A dual tapered dovetail shaped mortise is formed within a joist to receive a dual tapered dovetail shaped tenon extending from a beam. Laterally oriented cavities are disposed within opposite faces of the mortise to receive correspondingly configured ridges formed integral with the mating tenon. The resulting frictional interlock between the mortise and the tenon created by two forces acting in opposition to one another rigidly secures the beam to the joist without play therebetween. The ridges, mating with the corresponding cavities, affords use of the resulting joint in any plane from horizontal to vertical without danger of separation.

Claims

1. A beam suspension structure securing a beam to a joint in a building structure, said suspension structure comprising in combination:

a. a dual tapered dovetail mortise disposed within a planar side of the joist and extending downwardly from the top of the joist, said mortise including;

i. an end surface depending downwardly from the top of the joist and sloping forwardly toward said side of the joist, said end surface being laterally terminated by lateral edges sloping downwardly toward one another at an acute angle and defining the sides of an inverted truncated isosceles triangle;

ii. a pair of opposed lateral surfaces sloping downwardly toward one another and extending horizontally from said lateral edges of said end surface toward said side of the joist and toward one another, each said lateral surface being laterally terminated by a further lateral edge, said further lateral edges being sloped downwardly and toward one another at an acute angle within the plane of said side of the joist such that each said lateral surface defines an inverted truncated right triangle whereby a cross-section of said mortise defined by said end surface and said lateral surfaces and taken parallel to the top surface of the joist defines a trapezoid and resulting in said mortise being linearly tapered in both width and depth; and

b. a dual tapered dovetail tenon extending from a planar end of the beam, said tenon including;

i. a further end surface at the extremity of said tenon sloping downwardly and inwardly toward the beam at an angle equivalent to the sloping angle of said end surface of said mortise, said further end surface being laterally terminated by yet further lateral edges sloping downwardly toward one another at an acute angle and defining the sides of an inverted truncated isosceles triangle; and

ii. a pair of further lateral surfaces sloping downwardly toward one another and extending horizontally from said further lateral edges of said further end surface toward said end of the beam and toward one another, each said further lateral surface being laterally terminated by still further lateral edges, said still further lateral edges being disposed in the plane of said end of the beam and sloping downwardly and toward one another at an acute angle such that each said further lateral surfaces defines an inverted truncated right triangle, whereby a cross-section of said tenon defined by said further end surface and said further pair of lateral surfaces and taken parallel to the longitudinal axis of the beam defines a trapezoid and resulting in said tenon being linearly tapered in both width and depth;

c. said tenon being mated with said mortise each of the surfaces defining said mortise interferingly contact corresponding surfaces of said tenon to establish force vectors perpendicular to each of the pairs of contacting surfaces to draw and retain said planar end of the beam adjacent said planar side of the joist and frictionally interlock said planar side of the joist and frictionally interlock said mortise and said tenon.

2. A structure as defined in claim 1 including

detent means for engaging said pair of opposed lateral surfaces with said pair of opposed further lateral surfaces and establishing a structural interlock therebetween;

whereby, on mating of said mortise with said tenon the frictional interlock therebetween is augmented by the structural interlock,

said detent means comprises a depression disposed in each said lateral surfaces and a ridge disposed in each said further lateral surfaces for engaging the respective one of said depressions,

said depressions and said ridges lie within a plane parallel to a plane defined by the top of said joist.