Fixing device with a locking mechanism

• US 5,606,753 A
• Filed: 06/06/1995
• Issued: 03/04/1997
• Est. Priority Date: 06/20/1994
• Status: Expired due to Fees

• Current Assignee: Hashimoto Shinwa Setsubi, Limited
• Original Assignee: Hashimoto Shinwa Setsubi, Limited
• Inventors: Hashimoto, Toyoji
• Primary Examiner(s): Meyers, Steven N.
• Assistant Examiner(s): CONLEY, FREDRICK C
• Application Number:
  US08/471,520
• Time in Patent Office: 637 Days
• Field of Search: 411/7, 411/82, 411/190, 411/120, 411/121, 411/149, 411/150, 411/258, 411/930, 411/191, 411/198, 411/962, 411/963, 411/977, 411/978, 411/114, 411/330, 411/326
• US Class Current: 411/7
• CPC Class Codes: F16B 39/32 Locking by means of a pawl or pawl-like tongue
• CPC Class Codes: Y10S 411/962 Bolthead or nut-carried pawl
• CPC Class Codes: Y10S 411/978 Pawl and ratchet

Abstract

A fixing device with a locking mechanism includes a bolt having a hexagonal head, a seat attached to the bottom face of the bolt head, and a washer to be fit onto the threaded shaft of the bolt. The seat has an engagement portion which is raised from an outer edge of the seat along a side face of the bolt head to restrain the free rotation of the bolt with respect to the seat, and an elastic engagement pawl outwardly extending from a lateral end of the engagement portion. The washer has a plurality of engagement grooves which are engagable with the engagement pawl, and an antislipping means provided on the side which contacts the surface of a member to be fastened. When the bolt is fastened, the engagement pawl engages with one of the engagement grooves of the washer. This prevents the hexagon-head bolt from turning in a loosening direction. A locking function can be added to the fixing device without additionally machining the bolt or a member to be fastened. The locking mechanism can be unlocked using a box wrench.

Claims

1. A fixing device with a locking mechanism, comprising:

a bolt having a hexagonal head,

a seat attached to the bottom face of the bolt head,

a washer to be fit onto a threaded shaft of said bolt,

said seat having a generally planar central base portion and an engagement portion which is raised from an outer edge of said central base portion and fixedly located thereon so as to maintain a generally constant position along a peripheral side face of the bolt head to restrain the free rotation of said bolt with respect to said seat,

an elastic engagement pawl extending outwardly from a lateral end of said engagement portion,

said washer being provided with an annular rim which is raised from the peripheral edge of said washer to form a rimmed shape and a plurality of axially extending engagement grooves which are formed in an inner surface of the annular rim for engagement with said engagement pawl,

said washer having an antislipping means on the side which contacts a surface of a member to be fastened, and

said engagement pawl outwardly extending from said engagement portion elastically engaging with one of said engagement grooves formed in the inner surface of the annular rim of said washer when said bolt is fastened, thereby preventing said bolt from turning in a loosening direction.

2. A fixing device with a locking mechanism according to claim 1, wherein said engagement portion or said engagement pawl of said seat are partially extended to form an unlocking portion, said unlocking portion engaging with an edge of an opening of a box wrench when the box wrench is engaged with the bolt head so that said unlocking portion is deformed and said engagement pawl is disengaged from said engagement grooves of said washer, thus unlocking said fixing device.

3. A fixing device with a locking mechanism, comprising:

a bolt having a hexagonal head,

a seat attached to the bottom face of the bolt head,

a washer to be fit onto a threaded shaft of said bolt,

said seat having a generally planar central base portion and an engagement portion which is raised from an outer edge of said central base portion and fixedly located thereon so as to maintain a generally constant position along a peripheral side face of the bolt head to restrain the free rotation of said bolt with respect to said seat,

an elastic engagement pawl extending outwardly from a lateral end of said engagement portion,

said washer being provided with a plurality of radially extending engagement grooves which are formed in the peripheral edge of an upper surface of said washer for engagement with said engagement pawl, and said washer having an antislipping means on the side which contacts a surface of a member to be fastened, and

wherein said engagement pawl extending outwardly from said engagement portion elastically engages with one of said engagement grooves formed in the peripheral edge of the upper surface of said washer when said bolt is fastened, thereby preventing said bolt from turning in a loosening direction.

4. A fixing device with a locking mechanism according to claim 3, wherein said engagement portion or said engagement pawl of said seat are partially extended to form an unlocking portion, said unlocking portion engaging with an edge of an opening of a box wrench when the box wrench is engaged with the bolt head so that said unlocking portion is deformed and said engagement pawl is disengaged from said engagement grooves of said washer, thus unlocking said fixing device.