Portable work bench

Abstract

An improved portable work bench includes a beam, legs for supporting the beam, and at least one bracket having first and second surfaces for contacting respective first and second sides of the beam, wherein the second surface is movable between a first position contacting the second side of the beam, and a second position not contacting the second side of the beam. A spring biases the second surface towards the first position.

Description

FIELD OF THE INVENTION

This invention relates generally to work benches and more particularly to a portable work bench that can support a power tool and a workpiece.

BACKGROUND OF THE INVENTION

It is common in the construction industry for users to bring their power tools to the work site. Thus, the users require a work surface at the work site to support the power tools for use. Preferably the work surface is at a certain height so that the user can comfortably use the power tool. In addition, the work surface should also be sufficiently portable to be easily moved around a work site.

In the past, users have disposed their power tools on sheets of wood which are in turn supported by two or more sawhorses. This arrangement, however, lacks the strength and stability for efficient operation, as well as being difficult to set up and move around the work site.

Accordingly, different support stands or work benches have been proposed in order to provide a portable work surface that can support a power tool. Some of these prior art solutions have been described in U.S. Pat. Nos. 1,864,840, 4,860,807, 4,874,025, 4,974,651, 5,193,598, and 5,421,231. However, these prior art solutions do not provide a platform supporting the power tool which can be moved horizontally so that the power tool can be moved without moving the workpiece.

Other prior art solutions, such as the one described in U.S. Pat. No. 5,592,981, provide a platform supporting the power tool which can be moved horizontally so that the power tool can be moved without moving the workpiece. However, they require that the user insert and slide the platform from the end of the workbench towards the desired position on the workbench.

SUMMARY OF THE INVENTION

In accordance with the present invention, an improved portable work bench is employed. The workbench may include a beam, legs for supporting the beam, and at least one bracket having first and second surfaces for contacting respective first and second sides of the beam, wherein the second surface is movable between a first position contacting the second side of the beam, and a second position not contacting the second side of the beam.

Additional features and benefits of the present invention are described, and will be apparent from, the accompanying drawings and the detailed description below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate preferred embodiments of the invention according to the practical application of the principles thereof, and in which:

FIG. 1 is a perspective view of a portable work bench of the present invention;

FIG. 2 is a side view of the work bench of FIG. 1 ;

FIG. 3 is a cross-sectional view of the work bench along line III—III of FIG. 2 ;

FIG. 4 is a cross-sectional view along line IV—IV of FIG. 3 ;

FIG. 5 is a top perspective view of a mounting bracket according to the present invention;

FIG. 6 is a bottom perspective view of the first embodiment of FIG. 5 ;

FIG. 7 is a partial cross-sectional view of a first embodiment of the mounting bracket of FIG. 5 ;

FIG. 8 is a partial cross-sectional view of a second embodiment of the mounting bracket of FIG. 5 ;

FIG. 9 is a close-up view of the area IX of FIG. 2 ;

FIG. 10 is a cross-sectional view along line X—X of FIG. 9 ;

FIG. 11 illustrates the stop tabs according to the present invention;

FIG. 12 is a partial perspective view of the assemblies disposed on the end of the portable work bench;

FIG. 13 is a partial side view of the assemblies disposed on the end of the portable work bench;

FIG. 14 is a top view of the portable work bench;

FIG. 15 illustrates a first embodiment of an extension arm lock assembly according to the invention;

FIG. 16 illustrates the lock assembly of FIG. 15 without a cover;

FIG. 17 illustrates a second embodiment of an extension arm lock assembly, where FIGS. 17A-17B show the lock assembly with and without a cover, respectively;

FIG. 18 is an exploded view of an extension arm assembly;

FIG. 19 is a partial cross-sectional view along line XIX—XIX of FIG. 18 ;

FIG. 20 illustrates a workpiece support assembly, where FIGS. 20A , 20 B and 20 C are exploded, front and side views of the assembly, respectively; and

FIG. 21 is a cross-sectional view along line XXI—XXI of FIG. 20 B.

DETAILED DESCRIPTION

The invention is now described with reference to the accompanying figures, wherein like numerals designate like parts. Referring to FIGS. 1 and 8 , a portable work bench 10 of the present invention is designed to carry a chop saw 100 and/or a workpiece (not shown). However, persons skilled in the art will recognize that the work bench 10 can support any power tool, such as a sliding compound miter saw, a drill press, a table saw, etc., any hand tools, or anything else that may need to be supported.

The work bench 10 has a structural body 11 and at least one mounting bracket 20 disposed on the structural body 11 . Preferably, the structural body 11 supports two mounting brackets 20 .

Referring to FIG. 3 , the structural body 11 is preferably elongated and tubular, and may have a thin wall which substantially defines the outer perimeter thereof. Such body 11 can withstand substantial amounts of torsional and lateral loads applied thereto. Body 11 can be made of extruded aluminum, bent metal, fabricated sheet metal, etc.

Body 11 may have rails 11 R and/or channels 11 TC, 11 SC, 11 BC to connect elements thereto, as explained below. In addition, body 11 may have two chambers 11 C for wholly or partially receiving extension arm assemblies 70 , as discussed below. Body 11 may also have a central wall 11 W to divide the chambers 11 C and/or increase the rigidity of body 11 .

In addition, the work bench 10 may have leg assemblies 30 for supporting the structural body 11 and mounting brackets 20 (and thus the chop saw 100 and/or workpiece). Referring to FIGS. 1-4 , the leg assemblies 30 may include a leg 31 pivotally connected to the body 11 via brackets 32 , 33 .

Preferably, leg 31 is made of metal, such as extruded aluminum. The cross-section of leg 31 may be round or ob-round (with two opposing substantially flat sides), such as shown in FIG. 4 .

Leg 31 may have an end 31 R, which may be made of an elastomeric material, a plastic or rubber. Preferably, the end 31 R is made of a material that prevents slippage of the leg 31 along a floor or other supporting surface.

Bracket 32 may wrap around the end of body 11 . Preferably, bracket 32 is made of metal, such as sheet steel. Bracket 32 may also be shaped so that it matches the upper profile of body 11 . Preferably, bracket 32 is attached to body 11 via screws 32 S, which may extend through bracket 32 and into channels 11 SC of body 11 , and threadingly engage nuts 32 N disposed in channels 11 SC. Persons skilled in the art should recognize that screws 32 S may be disposed in channels 11 SC, extend through bracket 32 and threadingly engage nuts 32 N disposed on bracket 32 . Persons skilled in the art should also recognize that washers may be provided between screws 32 S, bracket 32 , body 11 and nuts 32 N as necessary.

Similarly, bracket 33 may be made of metal, such as sheet steel. Preferably, bracket 32 is attached to body 11 via screws 33 S, which may extend through bracket 33 and into channel 11 BC of body 11 , and threadingly engage nuts 33 N disposed in channels 11 SC. Persons skilled in the art should recognize that screws 33 S may be disposed in channels 11 BC, extend through bracket 33 and threadingly engage nuts 33 N disposed on bracket 33 . Persons skilled in the art should also recognize that washers may be provided between screws 33 S, bracket 33 , body 11 and nuts 33 N as necessary.

As mentioned above, leg 31 may be pivotally connected to brackets 32 , 33 via screws 31 S, which may extend through bracket 32 , leg 31 and bracket 33 , and threadingly engage nuts 31 N disposed on bracket 33 , or vice versa. Persons skilled in the art should also recognize that washers may be provided between screws 31 S, brackets 32 , 33 , leg 31 and nuts 31 N as necessary.

It is preferable to provide leg assembly 30 with a detent mechanism 35 to maintain the leg 31 in predetermined positions. Different detent mechanisms 35 may be found in U.S. Pat. Nos. 4,605,099 and 5,592,981, which are hereby incorporated by reference. Preferably, detent mechanism 35 includes a detent pin 35 P, which engages a hole 32 H in bracket 32 . Detent pin 35 P may be spring-biased towards engagement with hole 32 H via a spring 35 S. A retainer 35 R, such as a C- or E-clip, may be disposed between pin 35 P and leg 31 , to prevent escape of the pin 35 P. Persons skilled in the art should recognize that the pin 35 P and hole 32 H may be disposed alternatively on bracket 32 and leg 31 , respectively.

Referring to FIGS. 1 and 5 - 8 , a power tool 100 may be mounted to workbench 10 via mounting brackets 20 . Mounting brackets 20 may mount onto beam 11 . Preferably, the mounting brackets 20 engage the top and/or outside of rails 11 R. Alternatively, the mounting brackets 20 could engage the insides of rails 11 R, i.e., channel 11 TC.

Mounting bracket 20 may have a body 21 , which may be made of a metal, such as extruded aluminum, sheet steel, etc. Body 21 may have slots 22 for mounting the power tool 100 . As shown in FIG. 8 , the power tool 100 may be mounted onto body 21 with nuts 100 N and bolts 100 B. Bolt 100 B may extend upwardly through slot 22 and through a hole in power tool 100 , and threadingly engage nut 100 N. Alternatively, bolt 100 B may extend downwardly through a hole in power tool 100 and slot 22 , and threadingly engage nut 100 N.

Referring to FIGS. 5-8 , mounting bracket 20 preferably engages rails 11 R between a glide strip 25 and a lever 24 . Preferably, both the glide strip 25 and the lever 24 are made of plastic, such as nylon. Glide strip 25 is preferably attached to body 21 via a bolt 25 B, and an undercut 21 U. On the other hand, lever 24 is pivotally attached to body 21 via a bolt 24 B, or a boss.

Preferably, lever 24 is biased towards contact with rail 11 R. This may be achieved with a spring 27 , 27 ′. Referring to FIG. 7 , a spring 27 may be captured between a bent tab 23 and a lever boss 24 BB. Alternatively, a leaf spring 27 ′ may be captured by a bolt 28 and washer 28 W threadingly engaging the lever 24 ′ (see FIG. 8 ). Spring 27 ′ may be fixed or riveted to body 21 at the other end. Alternatively, if the bend on spring 27 ′ is deep enough, the upper end of spring 27 ′ may stay in place without requiring any fixing means.

With such construction, the user can easily dispose the power tool 100 on beam 11 . All the user needs to do is pull on levers 24 , and put mounting brackets 20 (and power tool 100 ) on beam 11 . To remove the power tool 100 from beam 11 , the user needs only to pull on levers 24 , and lift mounting brackets 20 (and power tool 100 ) from beam 11 .

Persons skilled in the art should recognize that such arrangement can be tuned by the manufacturer between a slidable bracket 20 or a locking bracket 20 . In other words, by changing the strength of spring 27 , 27 ′, the shape of lever 24 , 24 ′, the composition of glide strip 25 and/or lever 24 , 24 ′, etc., the manufacturer can “program” the bracket 20 .

For example, if the user desires a mounting bracket that locks onto beam 11 so that it cannot be pushed along beam 11 unless a large force parallel to the longitudinal axis of beam 11 is provided onto bracket 20 and/or power tool 100 , the manufacturer can use a stronger spring 27 , 27 ′. Alternatively, the manufacturer can change the shape of lever 24 , 24 ′ so that tab 24 T ( FIG. 8 ) does not contact body 21 , allowing lever 24 to contact beam 11 with full spring force. Furthermore, the manufacturer can change the composition of glide strip 25 and/or lever 24 , 24 ′ so that they are “grippier” and less prone to sliding. Accordingly, the user can slide the mounting brackets 20 (and thus power tool 100 ) only when the user pivots levers 24 . When the user releases levers 24 , however, the mounting brackets 20 in effect lock in place.

On the other hand, if the user desires a mounting bracket that does not lock onto beam 11 so that it can be pushed along beam 11 with a small force parallel to the longitudinal axis of beam 11 provided onto bracket 20 and/or power tool 100 , the manufacturer can use a weaker spring 27 , 27 ′. Alternatively, the manufacturer can change the shape of lever 24 , 24 ′ so that tab 24 T ( FIG. 8 ) contacts body 21 , preventing lever 24 to contact beam 11 with full spring force. Furthermore, the manufacturer can change the composition of glide strip 25 and/or lever 24 , 24 ′ so that they are more slippery and more prone to sliding. Accordingly, the user can slide the mounting brackets 20 (and thus power tool 100 ) longitudinally at any time.

With such arrangement, if the user wants to lock the mounting brackets 20 in place, a locating mechanism 15 is required. Referring to FIGS. 1-2 and 9 - 10 , locating mechanism 15 may include a clip 15 C, which is preferably made of metal, such as sheet steel, or plastic. The clip 15 C may be held in place by a screw 15 S, which may extend through clip 15 C and into channel 11 SC, and threadingly engage a nut 15 N. Persons skilled in the art should recognize that the head of screw 15 S may be disposed within channel 11 SC, so that the screw 15 S extends outwardly through clip 15 C and threadingly engage nut 15 N.

Clip 15 C may have wings 15 CW extending therefrom. Preferably, wings 15 CW extend from both sides of clip 15 C. Accordingly, a user can locate bracket 20 on clip 15 C by disposing bracket 20 between the two wings 15 CW. Wings 15 CW may be inclined at an acute angle from the longitudinal axis of beam 11 . Intermediate wings 15 CW′ may also be disposed between clip 15 C and wings 15 CW. Intermediate wings 15 CW′ may be disposed at an angle steeper than the acute angle of wings 15 CW. Preferably, intermediate wings 15 CW′ are substantially perpendicular to the longitudinal axis of beam 11 , whereas wings 15 CW may be inclined at an angle of about 45°. Having such difference in angles may assist the user in locating clip 15 C with bracket 20 .

Preferably, the distance between intermediate wings 15 CW′ is about or larger than the width of bracket 20 . Accordingly, if a bracket 20 is disposed on clip 15 C between intermediate wings 15 CW′, the bracket 20 will have a small range of movement. Therefore, the bracket 20 is effectively limited in travel.

With such construction, a power tool 100 may be slidably disposed at any position on beam 11 . However, the movement of power tool 100 (and mounting brackets 20 ) will be limited only when one bracket 20 is disposed on a clip 15 C.

Persons skilled in the art will recognize the screw 15 S is preferably covered by bracket 20 when bracket 20 is installed on clip 15 C.

Brackets 20 may also have feet 26 attached thereto, so that, when power tool 100 and brackets 20 are removed from beam 11 , the user can disposed the power tool 100 and brackets 20 on a surface for further cutting, etc. Feet 26 may be made of rubber or other elastomeric material. In addition, feet 26 may be attached to body 21 via bolts 26 B.

Referring to FIGS. 3 and 11 , bracket 32 may have a portion 32 P, which may match the upper profile of beam 11 . However, portion 32 P may have tabs 32 T extending below the rails 11 R. Such tabs 32 T prevent brackets 20 from being moved beyond the end of beam 11 .

Referring to FIGS. 1-2 , beam 11 may also have a handle 16 . Preferably, the handle 16 is bolted onto beam 11 . Persons skilled in the art will recognize that handle 16 may be bolted directly onto beam 11 , or via a screw/nut assembly in combination with channel 11 BC, such as the one used for attaching bracket 33 . Persons skilled in the art will recognize that providing handle 16 on the underside of beam 11 will not inconvenience work being conducted on or above beam 11 .

Referring to FIGS. 1-3 and 12 - 14 , workbench 10 may have extension arm assemblies 70 on both ends thereof. An extension arm assembly 70 may include an extension arm 71 , which telescopes within channel 11 C in a retracted position and extends beyond the end of beam 11 in an extended position. Extension arm 71 may be made of a composite material, or a metal, such as steel or aluminum.

An end cap 71 C may be disposed at one end of extension arm 71 . Preferably, end cap 71 C is attached to arm 71 via bolt 71 CB. End cap 71 C may be made of plastic to facilitate movement of arm 71 along channel 11 C. Alternatively, sliding buttons or glides can be disposed instead of end cap 71 C. These glides may be made of plastic, such as nylon or UHMW.

Referring to FIGS. 1-3 , 12 - 14 and 18 - 19 , an end cap 72 may be disposed at the other end of arm 71 . End cap 72 is preferably made of metal, such as cast aluminum. End cap 72 may be attached to arm 71 via bolt 72 B.

Preferably, end cap 72 has upper surfaces 72 U which are substantially coplanar to the corresponding upper surfaces of rails 11 R. Similarly, end cap 72 may have bottom surfaces 72 B which are substantially coplanar with the corresponding surfaces of channel 11 TC. This would allow an assembly, such as work support assembly 80 (FIG. 1 ), which engages upper and bottom surfaces 72 U, 72 B and channel 11 TC when disposed on end cap 72 and beam 11 , respectively, to be movable between end cap 72 and beam 11 , and vice versa, without removal therefrom when end cap 72 and beam 11 are located adjacent to each other, such as is shown in FIG. 12 .

If the combined length of beam 11 and caps 72 (with retracted arms) is A (see FIG. 14 ), the length of each arm 71 is preferably more than half of length A. Accordingly, when both arms 71 are retracted, a portion of one arm 71 will overlap a portion of the other. However, when both arms 71 are expanded, the total length A′ of beam 11 and caps 72 would be at least about twice length A. Persons skilled in the art will recognize that, if the lengths of arms 71 is maximized for maximum length without being longer than beam 11 , the total length A′ will be between about 2-3 times length A.

It is desirable to lock arms 71 in any position relative to beam 11 . Accordingly, an arm locking mechanism 90 is discussed below. Referring to FIGS. 1-2 , 12 and 15 - 17 , arm locking mechanism 90 is preferably disposed on bracket 32 . A first embodiment of locking mechanism 90 is shown in FIGS. 15-16 , whereas a second embodiment of the mechanism is shown in FIGS. 1-2 , 12 and 17 .

Referring to FIGS. 15-16 , arm locking mechanism 90 may include a housing 92 , which is preferably bolted onto bracket 32 via bolts 92 B. Housing 92 may be made of plastic, and may have an opening 92 O for allowing arm 71 to extend therethrough.

In addition, housing 92 may have bearing surfaces 92 BS for supporting arm 71 and facilitating the sliding motion of arm 71 relative to channel 11 C (and thus beam 11 ). Bearing surfaces 92 BS are preferably made of plastic or nylon, and can be made integral to housing 92 .

A plate 98 may be disposed between bracket 32 and housing 92 . Plate 98 may be integral to bracket 32 , or it may be a separate piece that is preferably connected to bracket 32 via bolts 92 B. Plate 98 may have an opening 98 O for allowing arm 71 to extend therethrough.

A cam 95 may be captured between plate 98 and housing 92 . Preferably, cam 95 is pivotally connected to housing 92 and/or plate 98 to allow rotation of cam 95 about an axis substantially parallel to the longitudinal axis of beam 11 . Cam 95 may have a handle 95 H to enable the user to rotate cam 95 .

Cam 95 may have a cam surface 95 C which contacts a sliding lock 96 . Lock 96 is preferably captured between plate 98 and housing so that it can slide towards and away from cam 95 . Lock 96 may be made of plastic or rubber. Springs 97 may be disposed between lock 96 and plate 98 and/or housing 97 to bias lock 96 towards cam 95 .

With such arrangement, the user can lock arm 71 at a desired position by rotating cam handle 95 H. As handle 95 H is rotated, cam 95 (and thus cam surface 95 C) is rotated, pushing lock 96 towards openings 92 O, 98 O (and thus towards arm 71 ), locking arm 71 in place. To unlock arm 71 , the user needs only to move handle 95 H in the opposite direction, releasing the camming force, and allowing springs 97 to move lock 96 away from arm 71 .

FIGS. 1-2 , 12 and 17 illustrate the second embodiment of arm locking mechanism 90 , where like numerals refer to like parts. All the teachings of the first embodiment are incorporated herein by reference. Unlike in the first embodiment, the user rotates a knob 93 , which is connected to bracket 32 . Knob 93 may have an eccentric cam surface 93 C, which is received within an opening 96 O in lock 96 .

Accordingly, when the user rotates knob 93 , cam surface 93 C is rotated, causing a translational movement of lock 96 , thus locking arm 71 in place. To unlock, the user need only rotate knob 93 in the opposite direction. The second embodiment has the advantage that, since cam surface 93 C is captured within opening 96 O, springs 97 are not necessary. This is because the interaction between cam surface 93 C and opening 96 O retracts lock 96 .

Referring to FIG. 20 , a work support assembly 80 may be provided on end cap 78 and/or beam 11 . As discussed above, work support assembly 80 may engage upper and bottom surfaces 72 U, 72 B and channel 11 TC when disposed on end cap 72 and beam 11 , respectively. This would allow work support assembly 80 to be movable between end cap 72 and beam 11 , and vice versa, without removal therefrom when end cap 72 and beam 11 are located adjacent to each other, such as is shown in FIG. 12 .

Work support assembly 80 may include a lower body 81 , which may be made of bent sheet metal, such as steel. Lower body 81 may have at least one slot 81 S, which is preferably substantially vertical. Lower body 81 may slidingly receive middle body 82 , which may also be made of bent sheet metal, such as steel. Middle body 82 may also have at least one slot 82 S, which is preferably substantially vertical and/or aligned with slot 81 S.

The lower and middle bodies 81 , 82 may be held in place relative to each other by screws 81 B, which extend through slots 81 S, 82 S and engage a nut 81 N or wingnut 81 W on the other side. Persons skilled in the art will recognize that such construction will allow a user to move lower and middle bodies 81 , 82 vertically relative to each other.

An upper body 83 is preferably disposed on middle body 82 . Upper body 83 may be made of bent sheet metal, such as steel. Upper body 83 may have slots 83 S, which are preferably substantially horizontal. Middle and upper bodies 82 , 83 may be held in place relative to each other by screws 83 B, which extend through slots 83 S and holes 82 H on middle body 82 . Screws 83 B may be held in place by nuts (not shown), which may be integral to middle body 82 or upper body 83 , or may be separate therefrom.

Upper body 83 may have an upper support surface 83 SS for supporting a workpiece. Preferably, support surface 83 SS is substantially horizontal.

An end stop 84 may be pivotally attached to upper body 83 . Preferably, screws 84 B extend through stop 84 , washers 84 W (which may be made of nylon, plastic or metal), and upper body 83 , and threadingly engage nuts (not shown).

End stop 84 may have a substantially planar surface 84 E. Surface 84 E may be pivoted between first and second positions. In the first position, surface 84 E will preferably be substantially vertical. In addition, surface 84 E may face the power tool 100 , so that it can contact the workpiece and act as an end stop. In the second position (shown in broken lines in FIG. 20 C), surface 84 E is below support surface 83 SS (and thus below the workpiece). In other words, surface 84 E is effectively bypassed, so that the workpiece contacts only support surface 83 SS.

Persons skilled in the art will recognize that, with the arrangement described above, support surface 83 SS and/or surface 84 E can be adjusted vertically and/or horizontally.

As mentioned above, work support assembly 80 may be disposed in channel 11 TC of beam 11 . Accordingly, it is preferable to provide assembly 80 with the means for attachment thereon. Lower body 81 may have a lower plate 81 LP fixedly attached to lower body 81 . Lower plate 81 LP may be welded or riveted to lower body 81 . Lower plate 81 LP and/or lower body 81 may carry sliding pads 81 P and/or sliding rivets 81 SR for facilitating sliding of lower plate 81 LP and/or lower body 81 along beam 11 . Preferably, sliding pads 81 P and/or sliding rivets 81 SR are made of plastic, nylon, UHMW, etc.

Lower body 81 may carry a screw, which extends into a cavity 81 PC formed by lower plate 81 LP, and threadingly engage a retaining nut 85 N. Nut 85 N may have flanges 85 NF, which may extend through openings 81 NO and contact the underside of rails 11 R. Such screw may be a standard screw or thumbscrew. Accordingly, the user can rotate the screw, moving nut 85 N (and flanges 85 NF) upwardly into contact with the underside of rails 11 R, thus locking support assembly 80 in place.

Alternatively, such screw may be an adjustable screw assembly 85 , as shown in FIGS. 20B and 21 . Adjustable screw assembly 85 may have a lower screw 85 S for threadingly engaging nut 85 N and an inner pistil 85 I fixedly connected to screw 85 S. Pistil 85 I may be molded over screw 85 S. Pistil 85 may have outer grooves 85 IG formed thereon.

In addition, an outer shell 85 O may be slidably disposed on pistil 85 I. Outer shell 85 O preferably slides relative to pistil 85 I. Outer shell 85 O may have protrusions 85 OP which engage the grooves 85 IG, for fixing the axial location of outer shell 85 O relative to pistil 85 I. Outer shell 85 O may also have a handle for rotating outer shell 85 O with or without pistil 85 I.

A spring 85 OS may be disposed between pistil 85 I and a washer 85 W and/or outer shell 85 O for biasing the outer shell 85 O downwardly. In other words, spring 85 OS may bias protrusions 85 OP into engagement with grooves 85 IG.

With such construction, the user may rotate screw assembly 85 , moving nut 85 N (and flanges 85 NF) upwardly into contact with the underside of rails 11 R, thus locking support assembly 80 in place. If the user wants to adjust the axial position of handle 85 H to obtain better leverage, the user needs to lift handle 85 H and/or outer shell 85 O, rotate outer shell 85 O relative to pistil 85 I, and release outer shell 85 O. Spring 85 OS will then push outer shell 85 O back into engagement with grooves 85 IG of pistil 85 I.

Persons skilled in the art may recognize other additions or alternatives to the means disclosed herein. However, all these additions and/or alterations are considered to be equivalents of the present invention.

Claims

1. A work bench comprising:a beam; legs for supporting the beam; at least one bracket disposed on the beam for supporting a tool; a first extension arm connected to the beam, said first extension arm having first and second surfaces at an angle thereto; and a locking mechanism for locking the position of the first extension arm relative to the beam, the locking mechanism comprising a locking surface being movable between a first position contacting both first and second surfaces, and a second position not contacting both first and second surfaces, and a cam for moving the locking surface between the second and first positions.

2. The work bench of claim 1, wherein the locking mechanism further comprises a spring for biasing the locking surface towards the second position.

3. The work bench of claim 1, wherein the locking mechanism further comprises a spring for biasing the locking surface towards the cam.

4. The work bench of claim 1, wherein the locking mechanism is disposed on the beam.

5. The work bench of claim 1, wherein the first extension arm telescopes within the beam.

6. The work bench of claim 1, further comprising a second extension arm slidably connected to the beam.

7. The work bench of claim 6, wherein the second extension arm telescopes within the beam.

8. The work bench of claim 1, wherein the cam is movable about an axis substantially parallel to a longitudinal axis of the beam.

9. The work bench of claim 1, wherein the first extension arm is tubular.

10. The work bench of claim 1, wherein the first extension arm has a square cross-section.