Connection for securing a helically convoluted hose to a hose fitting

• US 4,174,858 A
• Filed: 12/06/1976
• Issued: 11/20/1979
• Est. Priority Date: 12/06/1976
• Status: Expired due to Term

• Current Assignee: White Consolidated Industries Incorporated
• Original Assignee: National Union Electric Corp.
• Inventors: Brooks, Joseph F.
• Primary Examiner(s): Callaghan, Thomas F.
• Application Number:
  US05/747,549
• Time in Patent Office: 1,079 Days
• Field of Search: 285/DIG. 4, 285/239, 285/251, 285/391, 285/7, 285/390, 285/238, 285/92, 285/334, 151/22, 85/47
• US Class Current: 285/7
• CPC Class Codes: A47L 9/242 Hose or pipe couplings
• CPC Class Codes: Y10S 285/903 Corrugated

Abstract

A connection for securing one end of a helically convoluted suction hose to a hose fitting such as is used to effect rapid engagement of the hose with or disengagement thereof from the suction inlet of a vacuum cleaner. The fitting includes a tubular portion having external threads of the same pitch as the unstressed convolutions of the hose so that the tubular portion can be threaded into the end of the hose. The cross sectional configuration of the threads is such as to resist relative rotation between the fitting and the end of the hose when the threads are engaged with the hose convolutions. Additional resistance to relative rotation between the fitting and end of the hose is provided by a collar at the inner end of the tubular portion, the collar serving as an abutment to cause compression and a reduction in the pitch of the convolutions of the hose between the threads and collar with continued threading of the fitting into the end of the hose after the end edge of the hose has engaged the collar. Barbs on the threads substantially increase the resistance to rotation of the fitting relative to the end of the hose in a direction to effect unthreading of these parts, the barbs being provided by sharp transverse edges and corners on the threads. Removal of the remnant of the hose remaining on the tubular portion after the hose has been severed adjacent to the end of the tubular portion in order to replace or repair the hose is facilitated by interrupted portions of the threads, such interrupted portions permitting axial slitting of the hose remnant and removal thereof from the tubular portion.

Claims

1. A connection for securing one end of a helically convoluted resilient hose to a hose fitting, each of the convolutions of said hose having inner surfaces defined by a pair of axially spaced, substantially radially extending side walls and a connecting end wall, and said fitting including a tubular portion extending into one end of said hose, said connection comprising at least a portion of one thread on the exterior of said tubular portion and having a pitch substantially the same as the pitch of the unstressed convolutions of said hose, said thread portion having substantially radially extending side walls and a substantially flat top so as to define a sharp edge at the intersection of each side wall with said top, said sharp edges frictionally engaging the inner surfaces of at least a portion of one of the convolutions of said hose, said thread portion also having spaced leading and trailing ends with respect to the relative direction of rotation of said tubular portion and said one end of said hose as these parts are being engaged, and barb means carried at the trailing end of said thread portion, said barb means comprising a sharp edge on the trailing end of said thread portion, said sharp edge extending transversely to said thread portion and being wider than said thread portion, the transverse width of said sharp edge also being greater than the internal width of the convolutions of said hose so that said sharp edge digs into the interior of at least one of the convolutions of said hose, whereby relative rotation between said one end of said hose and said tubular portion in a direction to effect disengagement of these parts is resisted when said thread portion is engaged with said portion of said convolution.

2. The hose connection of claim 1, in which the distance between the edges of said thread portion is greater than the space between the inner surfaces of the side walls of a convolution of said hose when said convolution is in an unstressed condition, whereby the portion of the convolution engaged by said thread portion is expanded when said thread portion is engaged with said portion of said convolution.

3. The hose connection of claim 1, in which a plurality of threads are provided on the exterior of said tubular portion, each of said threads has a pitch substantially the same as the pitch of the unstressed convolutions of said hose, and each of said threads has substantially radially extending side walls and a substantially flat top so as to define sharp edges at the intersections of the side walls and top of each thread, said sharp edges frictionally engaging the convolutions of said hose and increasing the resistance to relative rotation between said tubular portion of said fitting and said one end of said hose.

4. The hose connection of claim 1, in which said sharp edge is defined by an undercut in said thread portion at said trailing end.

5. The hose connection of claim 1, in which two transversely spaced corners are defined on said trailing end of said thread portion at each end of said sharp edge, said corners digging into the interior of one of the convolutions of said hose and increasing said resistance to rotation of said one end of said hose relative to said tubular portion in said direction effecting disengagement of said parts.

6. The hose connection of claim 1, in which at least one thread is provided on the exterior of said tubular portion and at least two substantially diametrically spaced sharp edges are provided on said one thread.

7. The hose connection of claim 1, in which a plurality of threads are provided on the exterior of said tubular portion, each of said threads has a pitch substantially the same as that of the convolutions of said hose and at least a portion of each thread is removed to define leading and trailing ends adjacent to said removed portion, and a transversely extending sharp edge is provided on the trailing end of each of said threads.

8. The hose connection of claim 7, in which at least two complete threads are provided on the exterior of said tubular portion, at least two portions of each thread are removed to define two pairs of leading and trailing ends on each thread, and a transversely extending sharp edge is provided on each of said trailing ends.

9. The hose connection of claim 8, in which about two and one quarter threads are provided on the exterior of said tubular portion so that five trailing ends are defined on said tubular portion.

10. A connection for securing one end of a helically convoluted flexible hose to a hose fitting, said connection comprising a fitting having a tubular portion extending into one end of said hose, said tubular portion having thread means on the exterior thereof and being threadable into the convolutions of said end of said hose in response to rotation of said tubular portion relative to said end in a direction to effect engagement of these parts, said thread means including at least a portion of one thread on said tubular portion, said thread portion having a transverse width substantially equal to the internal width of the convolutions of said hose, said thread portion also having barb means which digs into the interior of at least one of the convolutions of said hose so as to resist rotation of said one end of said hose relative to said tubular portion in a direction to effect disengagement of these parts, and an abutment on the exterior of said tubular portion and spaced inwardly from said thread portion, said abutment engaging the end edge of said hose and causing compression and a change in the pitch of a plurality of the convolutions of said hose between said portion of said thread and said abutment with continued rotation of said tubular portion relative to the end of said hose after said end edge has engaged said abutment, whereby said barb means and the change in pitch of the compressed convolutions of said hose between said abutment and said thread portion increases the resistance to rotation of said one end of said hose relative to said tubular portion in a direction to effect disengagement of these parts.

11. The hose connection of claim 10, in which the tubular portion of said hose fitting has axially inner and outer ends, said thread portion is located intermediate said ends, and said abutment is located at said inner end.

12. The hose connection of claim 11, in which said thread portion has a pitch substantially the same as that of the convolutions of said hose when the latter is unstressed.

13. The hose connection of claim 10, in which said abutment comprises a collar extending radially outwardly from said tubular portion.