EP1216795A1

EP1216795A1 - Locking device and guide member for a movable jaw of an adjustable wrench

Info

Publication number: EP1216795A1
Application number: EP00126903A
Authority: EP
Inventors: Mei-Jung Wang
Original assignee: WANG MEI JUNG
Current assignee: WANG MEI JUNG
Priority date: 2000-12-08
Filing date: 2000-12-08
Publication date: 2002-06-26

Abstract

An adjustable wrench includes a handle and a head extended from the handle. The head includes a fixed jaw, a movable jaw, and an adjusting screw. The movable jaw is rectilinearly movable relative to the fixed jaw upon rotation of the adjusting screw. A locking device is provided for locking the adjusting screw in place to thereby preventing rotation of the adjusting screw. A guide member is provided for guiding rectilinear movement of the movable jaw to thereby prevent staggering of the movable jaw.

Description

Background of the Invention

1. Field of the Invention

The present invention relates to a locking device for retaining a movable jaw of an adjustable wrench after a fastener has been held between the movable jaw and a fixed jaw of the adjustable wrench. The present invention also relates to a guide member for preventing staggering of the movable jaw.

2. Description of the Related Art

Fig. 7 of the drawings illustrates a conventional adjustable wrench. It is well known to use an adjustable wrench for holding and driving fasteners (e.g., nuts, bolts, etc.) of various sizes. After the fastener has been securely clamped between the movable jaw 1 and the fixed jaw 3 by means of rotating an adjusting screw 2 of the adjustable wrench, the adjusting screw 2 is rotated in a reverse direction to form a gap between the jaws and the fastener for allowing easy disengagement of the jaws from the fastener and reengagement of the jaws with the fastener. The disengagement/reengagement of the jaws from/with the fastener are repeated until the fastener is tightened or loosened. If the gap is too small, the disengagement/reengagement is very difficult, yet the corner areas of a hexagonal outer periphery of the fastener will be damaged if the gap is too large. In addition, the adjusting screw tends to be rotated inadvertently during operation of the adjustable wrench such that the gap becomes larger, which results in damage to the corner areas of the fastener. The adjustable wrench is thus known as "nut killer". Further, the upper and lower side walls 4 (only one of them is shown) of the head of the adjustable wrench are apt to damaged or deformed, as some users use the adjustable wrench as a hammer. As a result, the movable jaw 1 staggers when holding a fastener and thus causes damage to the corner areas of the fastener.

Summary of the Invention

It is an object of the present invention to provide a locking device for retaining a movable jaw of an adjustable wrench after a fastener has been held between the movable jaw and a fixed jaw of the adjustable wrench.
It is another object of the present invention to provide a guide member for preventing staggering of the movable jaw of an adjustable wrench.
In accordance with a first aspect of the invention, an adjustable wrench comprises:
a handle;
a head extended from the handle, the head including a fixed jaw, a movable jaw, and an adjusting screw, the movable jaw being rectilinearly movable relative to the fixed jaw upon rotation of the adjusting screw; and
means for locking the adjusting screw in place.
The movable jaw includes a rack portion for engaging with the adjusting screw, and the head includes a track groove along which the rack portion of the movable jaw is moved. The head includes a compartment that is defined by two mutually facing walls and that is communicated with the track groove. The adjusting screw is freely rotatably received in the compartment. One of the walls includes a blind hole, and the other wall includes a screw hole. The locking means includes a locking rod that extends through the blind hole, the adjusting screw, and the screw hole. The locking rod includes a threaded portion that engages with the screw hole, and the locking rod is rotatable to a position such that the threaded portion of the locking rod is in contact with the adjusting screw, thereby preventing rotation of the adjusting screw. A turn-piece is mounted to an end of the locking rod for manually turning the locking rod by the turn-piece. The end of the locking rod includes a slit and a transverse through-hole. The turn-piece includes an end received in the slit of the locking rod. A pin is extended through the transverse through-hole of the end of the locking rod and a hole in the end of the turn-piece.
The head includes an end opposite to the fixed jaw, the end of the head including two mutually facing upper and lower side walls, the upper side wall including a first hole, the lower side wall including a second hole that is aligned with the first hole. A guide member is extended through the first hole and the second hole. The movable jaw comprises a groove in which the guide member is located, whereby rectilinear movement of the movable jaw is guided by the guide member. The guide member may be a bolt or a pin.
In accordance with a second aspect of the invention, an adjustable wrench comprises:
a handle;
a head extended from the handle, the head including a fixed jaw, a movable jaw, and an adjusting screw, the movable jaw being rectilinearly movable relative to the fixed jaw upon rotation of the adjusting screw; and
means for guiding rectilinear movement of the movable jaw.
In accordance with a third aspect of the invention, an adjustable wrench comprises:
a handle;
a head extended from the handle, the head including a fixed jaw, a movable jaw, and an adjusting screw, the movable jaw being rectilinearly movable relative to the fixed jaw upon rotation of the adjusting screw;
means for locking the adjusting screw in place; and
means for guiding rectilinear movement of the movable jaw.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

Fig. 1 is a perspective view of a head portion of an adjustable wrench in accordance with the present invention.
Fig. 2 is an exploded perspective view of the head portion of the adjustable wrench in accordance with the present invention.
Fig. 3 is a top view of the head portion of the adjustable wrench in accordance with the present invention,.
Fig. 4 is a top view similar to Fig. 3, illustrating operation of the adjustable wrench.
Fig. 5 is a top view similar to Fig. 4, wherein a locking device of the adjustable wrench is in a locking position for preventing displacement of an adjusting screw.
Fig. 6 is an exploded perspective view of a modified embodiment of the head portion of the adjustable wrench in accordance with the present invention.
Fig. 7 is a top view of a conventional adjustable wrench.

Detailed Description of the Preferred Embodiment

Referring to Figs. 1 through 6 and initially to Figs. 1 through 3, an adjustable wrench 200 in accordance with the present invention generally includes a handle 20 and a head 10 extended from the handle 20. The head 10 includes a fixed jaw 11 formed on a side thereof and a movable jaw 50. The other side of the head 10 includes a track groove 12 defined therein along which a rack portion 51 of the movable jaw is moved. The other side of the head 10 includes two mutually facing upper and lower side walls 121 and 123, the upper side wall 121 having a hole 122 and the lower side wall 123 having a screw hole 124 aligned with the hole 122. A guide member 13 (in the form of a bolt) is extended through the hole 122 and the screw hole 124. As illustrated in Fig. 3, the bolt 13 is received in a groove 52 in the movable jaw 50 to guide rectilinear movement of the movable jaw 50 relative to the fixed jaw 11, thereby preventing staggering of the movable jaw 11. The diameter of the bolt 131 is the same as or slightly smaller than a width of the groove 52. In conventional designs, the movable jaw 11 tends to stagger when it is moved away from the fixed jaw 11 by a larger distance, yet this drawback is mitigated by the provision of the guide member (i.e., the bolt) 13. The bolt 13 also provides improved structural strength for the head 10 of the adjustable wrench 200.
The head 10 of the adjustable wrench 200 further includes an opening or compartment 14 for rotatably receiving an adjusting screw 30 that meshes with the rack portion 51 of the movable jaw 50. A blind hole 16 is defined in a wall 14a that defines a portion of the compartment 14, and a screw hole 15 is defined in another wall 14b that defines another portion of the compartment 14 and that faces the wall 14a, best shown in Fig. 2.
A locking device 40 is provided to retain the adjusting screw 30 in place after the movable jaw 50 has been moved to a position for tightening/loosening operation of a fastener. As illustrated in Fig. 2, the locking device 40 includes a locking rod 41 and a turn-piece 42. The locking rod 41 has a threaded portion 413 and a slit 411 defined in an end thereof. A pin 43 is extended through a transverse through-hole 412 in the end of the locking rod 41 and a hole 421 in an end of the turn-piece 42 that is received in the slit 411 of the locking rod 41. The locking rod 41 is extended through the screw hole 15, a longitudinal hole 33 of the adjusting screw 30, and the blind hole 16. An elastic member 32 is mounted around the locking rod 41 and attached between the wall 14a and an end of the adjusting screw 30 for biasing the adjusting screw 30 toward the other wall 14b. The adjusting screw 30 may rotate freely in the compartment 14 for moving the movable jaw 50 away from or toward the fixed jaw 11. The adjusting screw 30 has a helical anti-slip surface 31 to avoid slip during manual rotation.
Referring to Fig. 4, when in use, the movable jaw 50 is moved toward the fixed jaw 60 upon manual rotation of the adjusting screw 30 to securely clamp a fastener (e.g., a nut 60). Next, the adjusting screw 30 is rotated in a reverse rotation to obtain required gap between the jaws 11 and 50 and the nut 60 for operation. Then, the tum-piece 42 is turned until the threaded portion 413 is in contact with the adjusting screw 30 (see Fig. 5), thereby preventing rotation of the adjusting screw 30. Thus, potential damage to the corner areas 61 of the nut 60 is prevented.
Of course, the adjustable wrench 200 may be retained in this status such that it can remain on the nut 60 even if the user's hand lets go. Thus, the user may leave the working site for other priority matters, and the adjusting wrench will be still there when he/she returns.
Fig. 6 illustrates a modified embodiment of the adjustable wrench, wherein the guide member is in the form of a pin 13a, and the hole 124 in the lower side wall 123 is not a screw hole.
Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.

Claims

An adjustable wrench (200) comprising:

a handle (20);

a head (10) extended from the handle (20), the head (10) including a fixed jaw (11), a movable jaw (50), and an adjusting screw (30), the movable jaw (50) being rectilinearly movable relative to the fixed jaw (11) upon rotation of the adjusting screw (30); and

means for locking the adjusting screw (30) in place.
The adjustable wrench as claimed in claim 1, wherein the movable jaw (50) includes a rack portion (51) for engaging with the adjusting screw (30), and wherein the head (10) includes a track groove (12) along which the rack portion (51) of the movable jaw (50) is moved.
The adjustable wrench as claimed in claim 2, wherein the head (10) includes a compartment (14) that is defined by two mutually facing walls and that is communicated with the track groove (12), the adjusting screw (30) being freely rotatably received in the compartment (14).
The adjustable wrench as claimed in claim 3, wherein one of the walls (14a) includes a blind hole (16), and the other wall (14b) includes a screw hole (15), and wherein the locking means (40) includes a locking rod (41) that extends through the blind hole (16), the adjusting screw (30), and the screw hole (15).
The adjustable wrench as claimed in claim 4, wherein the locking rod (41) includes a threaded portion (413) that engages with the screw hole (15), and wherein the locking rod (41) is rotatable to a position such that the threaded portion (413) of the locking rod (41) is in contact with the adjusting screw (30), thereby preventing rotation of the adjusting screw (30).
The adjustable wrench as claimed in claim 5, wherein the locking rod (41) includes an end, further comprising a turn-piece (42) mounted to the end of the locking rod (41) for manually turning the locking rod (41) by the turn-piece (42).
The adjustable wrench as claimed in claim 6, wherein the end of the locking rod (41) includes a slit (411) and a transverse through-hole (412), and wherein the turn-piece (42) includes an end received in the slit (411) of the locking rod (41), the end of the turn-piece (42) including a hole (421), further comprising a pin extended through the transverse through-hole (412) of the end of the locking rod (41) and the hole (421) of the end of the turn-piece (42).
The adjustable wrench as claimed in claim 2, wherein the head (10) includes an end opposite to the fixed jaw (11), the end of the head (10) including two mutually facing upper and lower side walls (121,123), the upper side wall (121) including a first hole (122), the lower side wall (123) including a second hole (124) that is aligned with the first hole (122), further comprising a guide member (13) extended through the first hole (122) and the second hole (124), the movable jaw (50) comprising a groove (52) in which the guide member (13) is located, whereby rectilinear movement of the movable jaw (50) is guided by the guide member (13).
The adjustable wrench as claimed in claim 8, wherein the guide member (13) is a bolt.
The adjustable wrench as claimed in claim 8, wherein the guide member (13) is a pin.
An adjustable wrench comprising:

a handle (20);

a head (10) extended from the handle (20), the head (10) including a fixed jaw (11), a movable jaw (50), and an adjusting screw (30), the movable jaw (50) being rectilinearly movable relative to the fixed jaw (11) upon rotation of the adjusting screw (30); and

means for guiding rectilinear movement of the movable jaw (50).
An adjustable wrench comprising:

a handle (20);

a head (10) extended from the handle (20), the head (10) including a fixed jaw (11), a movable jaw (50), and an adjusting screw (30), the movable jaw (50) being rectilinearly movable relative to the fixed jaw (11) upon rotation of the adjusting screw (30);

means for locking the adjusting screw (30) in place; and

means for guiding rectilinear movement of the movable jaw (50).