Mast assembly

• US 4,021,978 A
• Filed: 02/25/1976
• Issued: 05/10/1977
• Est. Priority Date: 10/17/1973
• Status: Expired due to Term

• Current Assignee: IRI International Corporation (NOV, Inc.)
• Original Assignee: Cabot Corporation
• Inventors: Welch, Raymond L., Moore, Hermus C. Jr., Busse, Ralph
• Primary Examiner(s): Purser, Ernest R.
• Assistant Examiner(s): Pate, III, William F.
• Application Number:
  US05/661,394
• Time in Patent Office: 440 Days
• Field of Search: 52/116-121, 403/13, 403/14, 403/161, 173/151
• US Class Current: 52/118
• CPC Class Codes: E21B 15/00 Supports for the drilling machine, e.g. derricks or masts
• CPC Class Codes: Y10T 403/1616 Position or guide means

Abstract

There is disclosed herein a telescoping mast assembly adapted for use with drill rigs and the like. The mast assembly comprises multiple sections, said sections being adapted for nesting one within the other in the telescoped-to-the-closed condition and each section comprising mutually convergent corner leg members which, when said mast assembly is extended, form concentric and in-line arrangements of the corner leg members from the base to the crown of the mast. Means are provided for connecting each mast section to its neighboring mast section upon extension thereof. In addition, means are also provided for indexing of the connector means upon extension of the mast assembly from its telescoped-to-the-closed condition.

Claims

1. A telescoping, nestable multiple-section mast assembly, said mast assembly having a generally rectangular cross-section, an open V-door side and a closed drawworks side, said mast assembly being adapted for extension and retraction in a substantially horizontal condition with the V-door side up and comprising at least two mast sections, including a lower base mast section and an upper crown mast section;

each mast section of said assembly comprising four mast leg members defining the corners thereof and extending in a substantially mutually convergent manner from the lower base end to the upper crown thereof;

the crown ends of each of said mast leg members of each lower mast section corresponding to and being in concentric and in-line arrangement with the base ends of the corresponding mast leg members of the adjacent upper mast section;

connector means between each of said lower and upper mast leg members, each of said connector means comprising

a female connector bracket comprising at least a pair of parallel spaced apart side plate members affixed to and extending from the end of one of the mast leg members, said side plate members being disposed vertically and substantially equidistantly bracketing the extended centerline of said one of the mast leg members with the mast assembly in the horizontal V-door-side-up condition, and a ramp element located between said side plate members, said ramp element being adapted to engage and provide vertical guidance to the corresponding male connector bracket of the other of said mast leg members during extension and retraction of the mast assembly, and

a corresponding male connector bracket comprising at least one plate element affixed to and extending from the end of the other of said mast leg members, said male connector bracket being disposed substantially along the extended centerline of said other of said mast leg members and each of the plate elements thereof being adapted for engagement into a corresponding space between the side plate members of said female connector bracket;

connector pin receiving apertures through said side plate members and plate element of said female and male connector brackets, said apertures being located so as to be coaxially aligned with one another upon establishing said one and said other of said mast leg members in their extended, concentric and in-line arrangement with one another, and

pin connector means adapted for insertion into said coaxially aligned apertures.

2. The mast assembly of claim 1 wherein, in each mast section, the side plate members of at least one pair of female connector brackets comprise a transverse stop notch located across the edges thereof and wherein each corresponding male connector bracket of the adjacent section comprises a stop pin extending transversely therethrough, said stop in being located to engage said stop notch upon gaining the limits of extension of the mast sections during extension of the mast assembly.

3. The mast assembly of claim 1 wherein the drawworks side of each lower mast section comprises parallel spaced apart guide rails oriented lengthwise on the interior thereof and each adjacent upper mast section comprises rub members depending from the exterior of the drawworks side thereof, said rub members being adapted to engage said guide rails of said lower mast section in sliding relationship therewith and said rub members depending sufficiently to maintain the connector brackets associated with the lower ends of the mast leg members of said adjacent upper mast section out of contact with said guide rails of said lower mast section during retraction and extension of said mast sections.