GB2029884A - Combined step-stool & workbench - Google Patents

Abstract

A folding work unit having at least one step 24, a seat 50, a vice unit 90, 92 positioned beneath the seat and to which access may be obtained by moving of the seat, a handrail 30 having an operative erect position and an inoperative storage position, the unit being capable of being used in any one of the following three workmodes, viz (i) a step-stool at which time the vice unit is covered by the seat and the handrail is in its storage position; (ii) a step ladder at which time the vice unit is covered by the seat and the handrail is in its operative erect position, and (iii) a workbench at which time the seat is moved to expose the vice unit and the handrail is in its storage position. A work tray may be connected to the handrail in its erect position. <IMAGE>

Description

SPECIFICATION Work unit This invention relates to work units, for example, for use in a household and in particular by the housewife in a kitchen and is concerned with the provision of a very flexible unit capable of use in a number of work modes.

Step-stools, step ladders and workbenches have, of course, been widely used for many years. Traditionally, these units have been considered distinct structures each having its own separate function, and typically a household will contain one or more of each. This not only has the disadvantage of requiring storage space for three units, but is frequently a serious inconvenience inasmuch as available storage space for some or all of the units is often out of the way, for example, in a garage or basement etc., Also, rather than go out of their way to get the appropriate unit, users many times would try to make do with what is close at hand. For example, a chair would be used to stand on, a stool to do carpentry work on, or perhaps a portable workbench to climb onto to reach high places, none of which can be safely or properly done.Thus, separate units are not only inconvenient, but also have shortcomings from the point of view of safety.

The present invention has, as its principal object, the provision of a construction which overcomes these shortcomings.

According to the present invention a folding portable work unit has at least one step, a seat, a vice unit positioned beneath the seat and to which access may be obtained by moving of the seat, a handrail having an operative erect position and an inoperative storage position, the unit being capable of being used in any one of the following three workmodes, viz (i) a step-stool at which time the vice unit is covered by the seat and the handrail is in its storage position; (ii) a step ladder at which time the vice unit is covered by the seat and the handrail is in its operative erect position, and (iii) a workbench at which time the seat is moved to expose the vice unit and the handrail is in its storage position.

The handrail is preferably pivoted between its operative erect position and its inoperative storage position. The unit may have a substructure incorporating the step and the substructure may be capable of folding to a storage mode in which case the sub-structure is preferably capable of folding to a storage mode whilst the handrail is in either its erect position or its storage position.

In a specific arrangement, the work unit includes a pair of spaced front legs and a pair of spaced rear legs with a step or steps extending between the front legs. In this case the handrail may be pivoted to upper portions of the front legs and in its inoperative storage position the handrail may lie in front of lower portions of the front legs but does not obstruct the step. The handrail is preferably latched in its operative erect position by engagement of handrail latching means extending between at least one front leg and the handrail. For example, the handrail may be latched by at least one portion of the seat.

The handrail may comprise a U-shaped member having the free ends of its side limbs pivoted to the front legs adjacent their upper ends and in its operative erect position the limbs extend generally parallel to the front legs.

The work unit may include a step rail extending between the rear legs which may serve as a footrest to stabilise the unit, particularly when it is being used in its workbench mode.

The vice unit may comprise a pair of horizontal extending vice members having flat upper surfaces lying in substantially the same plane to form a working surface, and a pair of spaced vice operating means being operatively connected to at least one of the members to move it with respect to the other member. Furthermore, the vice unit may include a pair of top rails extending from front to rear and supporting the vice members, the legs being pivotally connected to front and rear portions of the top rails for movement between an open position and a collapsed position.

Preferably manually releasable means is incorporated to retain the unit against folding from its open position and the releasable means may comprise co-operating latching members on at least one of the front legs and the vice unit.

The seat may be capable of folding to expose the vice unit and in its unfolded condition forms a tool tray which preferably blocks access to the step to ensure that the user cannot climb onto the top of the vice unit which may be a dangerous manoeuvre.

The invention may be carried into practice in a number of ways but two specific embodiments will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view from above and one side of a work unit formed in accordance with the present invention, and shown in its step ladder mode; Figure 2 is a side elevation of the unit of Fig. 1, with its handrail in a stowed position and its seat folded outwards to form a tool tray, the unit in Fig. 2 being in its workbench mode; Figure 3 is a perspective view corresponding to Fig. 2; Figure 4 shows the unit in a partially folded condition; Figure 5 is an enlarged perspective view of certain parts of the work unit including the latching mechanism; Figure 6 is a sectional side elevation showing the mechanism by which the work top vice of the unit operates;; Figure 7 is a scrap view in side elevation of the latching mechanism which prevents the unit folding; Figure 8 is a view of one of two latches for the handrail; Figures 9 and 10 show the location of certain of the instantaneous centres of relative rotation as the work unit begins to fold; Figure 10 also illustrates how inclined forces applied to the work unit may tend to cause it to fold.

Figure 11 is a perspective view of an alternative form of work unit of which the safety rail is shown in an operative position forming a step ladder; Figure 12 is a perspective view of the unit of Fig. 11 in its workbench mode with the safety rail in the storage position and the seat top folded to an open condition to reveal a vice unit; Figure 13 is a side elevation of the work unit of Figs. 11 and 12; Figure 14 is a side elevation showing the work unit in a half-folded condition; Figure 15 is a side elevation showing the work unit in a fully folded condition; Figure 16 is a scrap view showing the manner of folding of the safety rail; Figure 17 is a sectional plan showing the brackets supporting the safety rail; Figure 18 is a detail of a hinge for the top; Figures 19 and 19A are enlarged crosssections showing parts of the vice unit;; Figure 20 is a cross-section on the line 10-10 of Fig. 19; and Figure 21 is a detail view of the vice handle.

The work unit shown in the Figs. 1 to 10 has three distinct modes of use, namely, as a step ladder when a handrail is raised as in Fig. 1, as a small workbench when a seat is unfolded to form a tool tray as shown in Fig.

2, and as a step-stool when the seat is returned to its normal position.

The unit incorporates a pair of front legs 10 and a pair of rear legs 11. The upper ends of the legs 10 and 11 are pivotally connected to a pair of spaced rails 12, which form part of a top structure, the rails 1 2 each being of inverted U form. The front legs 10 are connected to the rails 1 2 by means of pivotal connections 14, of which one is shown in Fig.

5, whilst the rear legs 11 are connected to the rails 1 2 by means of pivotal connections 1 6 of which one is shown in Figs. 3 and 4.

The front leg TO and the rear leg 11 on each side are connected by respective braces 18, which braces are pivotally connected to the legs 10 and 11 by means of pivotal connections 20 and 22 respectively. In order that the unit can fold to the configuration shown in Fig. 4, in which the legs 10 and 11 are substantially parallel, the sum of the dimension between the pivots 14 and 1 6 plus the dimension between the pivots 16 and 22 is substantially equal to the sum of the dimension between the pivots 14 and 20 plus the dimension between the pivots 20 and 22.

The front rails 10 are interconnected by a pair of spaced steps, namely, a lower step 24 at a height of 200 mm and an upper step at a height of 400 mm.

The rear legs 11 are interconnected by a single horizontal rail 28 at a height of 1 80 mm which provides a ready means for stabilising the unit when in its workbench mode.

Each of the steps 24 and 26 and the rail 28 are provided with a ribbed tread surface.

Associated with the front legs 10 is a Ushaped handrail 30 having a pair of limbs 32 interconnected by a cross member 34. The handrail 30 is pivotally mounted on the front legs 10 by a pair of pivotal connections 36 positioned slightly below the pivotal connections 14 of the front legs 10 to the rails 1 2.

Figs. 2, 3, 4 and 5 show the handrail 30 in an inoperative stowed position in which it lies slightly in front of the lower parts of the front legs 10. It will be observed that the handrail 30 is slightly narrower adjacent the cross member 34 and in order to accommodate this narrow part of the handrail in the stored position, the lower step 24 has a pair of cut out corners 40 shown most clearly in Fig. 1.

The free ends of the limbs 32 of the handrail 30 extend slightly beyond the pivotal connections 36 and have at their extremeties latching mechanism in the form of spring loaded plungers 42 for securing the handrail in its operative position of Fig. 1. As is most clearly shown in Fig. 5, the front legs 10 each carry an abutment 44 having in it a hole 46 to accommodate the appropriate plunger 42 when the handrail is in its operative position.

The unit incorporates a moulded seat 50 having a depending flange 52. As shown in Fig. 5, at the front end of each side portion of the flange 52, the flange has secured to it a bracket 54, an end of which is connected by a pivotal connection 58 to a vertical limb 60 of an inverted-L-shaped bracket 62, the other horizontal limb 64 of which is secured to the front end of one of the rails 1 2. The seat also forms a top step or platform for the step ladder mode at a height of 608 mm. The platform is 250 mm in depth and 370 mm in width. In this manner, the seat 50 can be unfolded from its operative seat-forming position of Fig. 1 in order to uncover a worktop vice which will be described in detail later. In its unfolded position, the seat 50 lies horizontally, as shown in Figs. 2, 3 and 5 to form a tool tray. The tray includes a number of tool retaining clips as shown in Fig. 3. The seat has a pair of moulded indentations 60 which nest with the upper ends of the front legs 10 when the seat is forming a tray, as shown in Figs. 3 and 5, the indentations effectively providing abutments to prevent further rotation of the seat beyond its horizontal trayforming position.

Referring now to Fig. 5, extending from side to side, across the upper end of the unit, is a transverse rod 70 which is journalled in the forward ends of vertical limbs 72 of the rails 12.

The ends of the rod 70 each rigidly carry a collar 73 having a downwardly extending hook 74 of the detailed form shown in Fig. 7.

A hooked end 76 of each hook 74, in the erect condition of the unit, engages under an abutment surface 78 of an abutment block 80 secured to the upper end of the front leg 10 on that side. By means of a small coil spring 84, the rod 70 is biassed in a rotary direction to engage the hook 74 with the abutments 80. This effectively maintains the hooks in their latched positions in which they prevent collapse of the unit by folding about the pivots 14, 16, 20 and 22. Such folding would otherwise tend to occur when certain loads are applied to the top of the unit.

The unfolding movement of the unit is limited at the erect position of the legs by engagement of the abutment blocks 80 with the ends of the rod 70.

The hooks have cam surfaces 77 which bias the hooks to an open position as the unit is unfolded, but as soon as the hooks clear the abutment surfaces 78, the coil spring 84 biases the hooks into their engaged positions.

The latches formed by the hooks, apart from preventing collapse during use, also maintain the structure erect if it is lifted, say by its erect handrail. The fact that the surface 78 of the latch is formed on the abutment block 80 and the hooks 74 are formed on the collars 73 which abut against the blocks 80 makes for considerable simplicity and assist in overcoming tolerance problems which exist when trying to ensure that two parts abut to form a stop (the collars 73 and the blocks 80) simultaneously with the engagement of the latches.

Figs. 9 and 10 help to illustrate why such collapse may tend to occur. The geometry of the folding parts of the work unit dictates that the feet of the front legs 10 will move towards the feet of the rear legs 11 as the work unit begins to fold, so that some sliding of one or other of the sets of feet must occur. If the feet of the front legs 10 slide, while the feet of the rear legs 11 remain stationary, the centre of rotation of the front legs relative to the rear legs adopts the position shown at 200; the centre of rotation of the front legs 10 relative to the floor adopts the position shown at 202; and the centre of rotation of the top of the work unit relative to the floor, adopts the position shown at 204, all as shown in Fig. 9.Alternatively, if the feet of the front legs 10 remain stationary, while the feet of the rear legs 11 slide, the position of the centre of rotation of the front legs relative to the rear legs remains at 200; the centre of rotation of the rear legs 11 relative to the floor will adopy a position shown (diagrammatically only, because of its considerable distance from the other centres) at 202' in Fig.

10; and the centre of rotation of the top of the work unit relative to the floor will adopt the position shown at 204', all as shown in Fig. 10. From a comparison of Figs. 9 and 10, it can be seen that the horizontal position of the centre of rotation of the top of the work unit is the same in either case; it lies above a point 206 close to the rear of the top structure.

If friction between the feet and the floor is neglected, it can be seen that a pure vertical force applied to the top of the work unit at a point forward of the point 206 will tend to rotate the top anticlockwise, as seen in Fig. 9; such rotation corresponds to a movement in the sense from a folded condition to an erected condition, and therefore such a force will merely tend to hold the work unit more firmly in its erected condition. Conversely, a pure vertical force applied to the top of the work unit to the rear (i.e., to the right) of the point 206 will tend to rotate the top clockwise, collapsing the unit; such collapsing is however prevented by the hooks 74.

In the foregoing, friction between the feet and the floor is neglected, the effect of such friction will be that, even without the hooks 74, there would in practice be no danger of the work unit being collapsed by a pure vertical force. However, in some circumstances, a vertical force may be combined with a force directed forwardly (to the left in Fig. 10) and this will produce a stronger tendency for the work unit to collapse since the top of the work unit shifts forwards as collapsing occurs (assuming that all the feet remain in contact with the floor). The presence of a forwardly directed force will mean that, in collapsing, the rear feet of the work unit slide forwards, rather than the front feet sliding rearwards and therefore the centres of rotation will adopt the position of Fig. 10.

If the self-weight of the work unit is neglected, and the force applied to the top of the work unit is considered as comprising a vertical component V and a horizontal component H, the vertical reaction N at the rear feet will be given by the following equation: N.a=V.b-H.c (1) where, as shown in Fig. 10, a is the span between the front and rear feet; b is the horizontal distance from the front feet to the point of application of the force; and C is the vertical distance from the front feet to the point of application of the force.

For slipping of the rear feet to just begin, the work done by the two force components as the top of the work unit moves must just equal the energy absorbed by friction at the rear feet. For a small movement 8 of the rear feet, it can be shown that the point on the top of the work unit to which the force components H and V are applied will move horizontally by a distance ÇH= S e g (2) df where, as shown in Fig. 10, d is the distance from the point 202' to the rear feet; e is the distance from the point 202' to the pivot 16; f is the distance from the pivot 1 6 to the point 204'; and g is the vertical distance from the point 204' to the point of application of the force.

Similarly, the point of application of the forces will shift vertically by a distance ssv= S eh (3) df where h is the horizontal distance between the point 206 and the point of application of the force; if the latter point is forward of the former; this will result in an upward movement, and an upward dv will be taken as positive.

If the coefficient of friction at the rear feet is 211, then, for slipping just to begin, y NÇ = H ÇHV8V (4) Equations (1) to (4) can readily be solved to give a value for the maximum ratio of H to V, for each possible point of application of force to the top of the work unit. The arrows 208 in Fig. 10 show the positions of the lines of action of a number of forces which are just sufficiently inclined to initiate collapsing of the work unit in the absence of the hooks 74, for a coefficient of friction of 0.3. As can be seen, most of these lines of action pass appreciably to the right of the point 204', since a definite clockwise moment about this point is required to overcome friction and initiate collapse.However, the most leftward of the illustrated lines of action passes through the point 204', since a force applied along this line will be borne entirely by the front feet, and will not create any friction at the rear feet.

When it is desired to fold the unit, the hooks 74 can be very simply released by means of an upward and forward force ap plied to a release member 84 secured to the central portion of the rod 70. Such release will normally occur when the seat 50 is in the operative position of Fig. 1 at which time access can be had to the release member 84 via a notch 86 formed in the flange 52 of the seat 50.

The vice which forms the top of the work unit will now be described. It includes a fixed, rear, elongate vive member 90 and a movable front vice member 92. The fixed vice member 90 is secured to the rails 1 2 by pairs of bolts 94 and, with the rails 12, forms a U-shaped top structure of considerable rigidity. Referring to Fig. 6, extending within each of the Ushaped rails 1 2 is a vice operating screw 100 having at its rear end an operating handle 102. Adjacent the handle, the screw 100 is mounted in a journal bearing 104 secured in the rail 12.The screw 100 carries a nut 106 having a bolt 108 extending vertically upwards therefrom through a slot 110 in the horizontal web of the rail 12, the bolt connecting the nut 106 to the movable vice member 92, to form a vertical pivotal connection which enables arcuate movement of the movabde vice member 92 to occur during independent operation of one vice screw 100 without operation of the other vice screw. In this manner, the vice can be readily operated by a user holding a workpiece in one hand between the vice members and aternating the operation of the handles 1 02. This facility also enables the clamping of tapered workpieces between the clamping faces 1 20 of the two vice members.

The presence of the tool retaining clips, on the underside of the seat makes it necessary to open the vice members to substantially their full spacing in order to allow the clips between them. This has the advantage that the movable vice member 92 is then in a good position partially to support the seat from its underside. The seat is also supported by the stationary vice member 90 at this time.

It is to be noted that in its workbench mode of Fig. 3, both the handrail and the tool tray are well below the upper level of the vice members to provide unobstructed access thereto.

The height of the top of the handrail in its operative position is 1080mm which is at a convenient height in relation to the rest of the structure for a user when standing on the seat 50 to rest his or her knees against the hand rail.

Each vice member has in it four spaced vertically extending bores 1 22 to receive plugin attachments of the type described in British Patent No. 1,422,521, to enable workpieces wider than the maximum gap between the work faces 1 20 to be accommodated and also to enable workpieces of irregular shape to be clamped by the vice.

The work unit described is ideally suited for use in the home and has three main functions, namely, a step-stool, a step ladder or a miniature workbench. It can be readily converted from one to the other in a matter of moments and also can be stored away in a small storage space simply by folding to the configuration of Fig. 4. It is to be noted however that the unit can be collapsed to storage condition, with the handrail in its raised position if required. The unit is extremely stable when erected due to the forward and rearward inclination of the front and rear legs, and also due to the lateral splay of the lower part of the legs.

From its collapsed configuration of Fig. 4, the unit can be readily erected simply by resting the feet of the rear legs on the floor and allowing the front legs and seat structure to fold downwards automatically.

It is to be noted that when the seat is unfolded to form a tool tray, the tray effectively blocks access to the steps so that there is little risk of a user attempting to use the unit as a step-stool whilst the vice unit is uncovered.

Figures 11 to 21 illustrate an alternative embodiment having a top structure which incorporates a plastics moulded seat 310 arranged to fold about a pair of hinges 311, in a manner to be described in more detail, to an open position or workbench mode of Fig. 1 2 to reveal a vice unit. The stool incorporates a pair of vertically spaced steps, namely, an upper step 312 and a lower step 314 each pivotally mounted between the upright limbs 316 of a front frame generally indicated at 318, the limbs 31 6 merging at their lower ends into a horizontal rail 320 having a pair of feet 322. The frame 318 is made of tubular metal.

A similar rear frame 324 is provided having side limbs 326 and a lower rail 328, also provided with feet 322.

The top structure, of which the seat 310 forms a part, also includes a pair of generally L shaped supports 330 extending from front to back, each support having a vertical web 332 and a horizontal web 334. The upper end of the limbs 316 of the front frame 318 are connected to the vertical webs 332 of the supports 330 by means of pivotal connections 336 situated quite close to the front ends of the supports 330. Also pivoted to the vertical webs 332 of the supports 330, but adjacent their rear ends are sloping links 340 which are connected to the webs 332 by pivotal connections 342 situated at a higher level than the pivotal connections 336. The slope of the links 340 on each side is the same as the slope of the front frame 318.The links 340 are connected, by means of pivotal connections 344 and 346 respectively, to extensions 348 and 350 on the rearward sides of the upper and lower steps 312 and 314. As has been mentioned, the steps 312 and 314 extend between the upright limbs 316 of the front frame 31 8 and they are connected to these limbs by further pivotal connections 352 and 354 respectively. In this way, the six pivotal connections 336, 342, 352, 344, 354 and 346, together with the two steps, the supports 330, the rails 316 and the links 340 form a parallelogram linkage with the three pivots 336, 352 and 354 extending in one line and the pivots 342, 344 and 346 extending in another line lying parallel to the first line.

It is to be noted that the side limbs 326 of the rear frame 324 are also pivoted, by the pivotal connections 344, to the upper step 348 and the link 340. Adjacent their upper ends, the side limbs 326 of the rear frames 324 are pivotally connected at 358 to short boomerang-shaped links 360, the other ends of which are pivotally connected at 362 to the side limbs 316 of the front frames 318 substantially mid-way between the pivotal connections 336 and 352. Above the pivotal connections 358, the side limbs 326 of the rear frame 324, have at their upper ends, plastics abutments 366, arranged in the erected condition of Fig. 1 3 to abut the front limbs 316 of the front frames 318 closely adjacent to the upper pivots 336.

The links 340 extend slightly below the lower pivots 346 with the lower step 314 and are connected to further rearwardly and downwardly extending links 370, the lower ends of which are pivoted at 372 to the lower ends of the rails 326 of the rear frame 324. Each link 370 has in it a longitudinal slot 374 to receive a pin connection 375 on the lower end of the link 340.

The arrangement described folds in the manner shown in Figs. 14 and 15. Thus, the limbs 332 of the top structure, the upper step 312, the lower step 324, the limbs 316 of the front frames 318 and the links 340 fold in the manner of a parallelogram. By virtue of the links 360, the upper ends of the limbs 326 of the rear frame 324 are constrained to move in arcuate paths around the pivots 362, the links 360 acting at this time as tension links and the pin 375 slides along the slot 374 in the link 370.In the fully folded condition of Fig. 15, it will be seen that the front and rear frames extend parallel to one another and to the link 340 and the top structure to form an extremely compact construction which can be housed in a small cupboard or hung on a wall by means of hooks 380 shown in Fig. 1 5. The constructions is also very compact from the point of view of packaging.

As shown in Fig. 12, the top structure of which the seat 310 and the supports 330 form a part, also includes a pair of horizontally extending vice members 382 and 384 of which the vice member 382 remains stationary and is secured by means of screws 386 to the horizontal web 334 of each support 330.

Thus, the two supports 330 and the stationary vice member 382 in effect form a rigid U when viewed in plan adding strength and rigidity to the unit as a whole.

The movable vice member 384 can be moved towards and away from the stationary vice member 382 by operation of a pair of vice handles 388 disposed on the side of the step stool remote from the steps. Each vice handle 388, as shown in Fig. 19, is secured on the end of a vice operating screw 390, which, adjacent the handle end is journalled in a trunnion 392 which, as shown in Fig.

10, is located in a cage 394 by means of a pair of studs 396 which allow certain pivotal movement around a vertical axis. In front of the trunnions 392, the vice operating screws are received within a nut 398 on each side, the nut having an upwardly projecting integral stud portion 400 which is secured to the movable vice member 384 by means of a screw 402 which in effect provides a vertical pivotal connection, by means of which the two vice operating handles can be operated to a substantial extent independently of one another in the manner described in Patent 1,267,032. Movement of the vice member 384 away from the stationary vice member 382 is limited by engagement of the nut 398 with the trunnion 392.Each vice member 382 and 384 is provided with a number of vertical bores therein to receive abutment members 408 by means of which workpieces, irregularly shaped or of a dimension larger than the maximum vice gap, can be clamped by the vice members while lying on their upper surfaces.

The detail form of the seat 310 will now be described. As has been mentioned, this is connected to the remainder of the top structure by the two hinges 311. These hinges are connected to the horizontal webs 334 as shown in Figs. 1 2 and 1 3. As has been mentioned, the seat 310 comprises a plastics moulding having an appropriately ribbed understructure so that it can bear on the upper surface of the vice members for support.

When the seat is in its operative position in which it may be latched, the vice members have to be spaced fully apart so that a tool box 420, shown in Fig. 12, can be located between the vice members. The tool box is secured to or formed integrally with the underside of the seat 310. Tools are stored in the box in cut out sections of foam plastics and the tool box has a lid 422 also lined with foam plastics. As shown in Fig. 12, on each side of the tool box 310, are shallower storage compartments containing e.g., an oil can and fuses which are located, when the seat is in its operative position, above the horizontal webs 334 of each of the supports 330.

When the seat is folded to its inoperative position of Fig. 12, it blanks off the top step and deters a user from mounting the open vice unit. The lower step however remains available and can be used by a foot, as shown for stabilising the stool, for example, when the vice is being used for planing.

As shown in Fig. 11, the unit has an inverted U-shaped safety and hand rail 430 comprising a pair of substantially vertical limbs 431 and 431 and a horizontal rail 433 which can serve as a hand rail. The lower ends of the limbs 431 and 432 are pivotally connected to brackets 434 secured by bolts 435 to the upright limbs 31 6 of the front frame 318.

As shown in Figs. 1 6 and 17, the brackets 434 are pivotally connected to the safety rail by pivot screws 436 which pass through plugs 438 located in the lower ends of the limbs 432 and 431 and secured in these limbs by means of bolts 440 which also connect collars 442 to the limbs. These collars 442 are arranged to be located in recesses 444 (see Fig. 1 3) formed on the side portions 446 of the seat 310. As the safety rail is swung upwards towards its operative position, the seat has to be lifted around the hinges 311 in order that the collars 442 can be received in the notches 444 but this can be achieved without folding the whole stool.

The safety rail has connected to it, a work tray 452, by strap hinges 450, of the form shown in Fig. 18. The tray incorporates a trough 453 having a lid 454 in which tools can be stored or a pot of paint or bucket located. A bucket 455 of a suitable shape is shown in Fig. 11. The tray 452 also has shallow recesses 456 suitable for small tools, nails, screws, light bulbs etc, In the storage position of the safety rail, i.e., in the step stool mode, it lies in the position shown in Fig. 13, at which time the tray 452 rests on the lower ends of the limbs 316 of the front frame 318. The trough 453 projects between the limbs 316 as shown.

The bottom 457 of the trough, at this time, is in line with the projecting rib 460 of the seat 310 as shown in Fig. 1 5, in order not to take any more room than is required for storage of the step stool in a rectangular box.

Claims (23)

1. A folding portable work unit having at least one step, a seat, a vice unit positioned beneath the seat and to which access may be obtained by moving of the seat, a handrail having an operative erect position and an inoperative storage position, the unit being capable of being used in any one of the following three workmodes, viz (i) a step-stool at which time the vice unit is covered by the seat and the handrail is in its storage position; (ii) a step ladder at which time the vice unit is covered by the seat and the handrail is in its operative erect position, and (iii) a workbench at which time the seat is moved to expose the vice unit and the handrail is in its storage position.

2. A work unit as claimed in Claim 1 in which the handrail is pivoted between its operative erect position and its inoperative storage position.

3. A work unit as claimed in Claim 1 or Claim 2 in which the unit has a sub-structure incorporating the step, the sub-structure being capable of folding to a storage mode.

4. A work unit as claimed in Claim 3 in which the folding into and out of the storage mode can occur when the handrail is in its erect position.

5. A work unit as claimed in Claim 3 in which the sub-structure is capable of folding to the storage mode whilst the handrail is in either its erect position or its storage position.

6. A work unit as claimed in any one of the preceding claims including a pair of spaced front legs and a pair of spaced rear legs with the or each step extending between the front legs.

7. A work unit as claimed in Claim 2 and as claimed in Claim 6 in which the handrail is pivoted to upper portions of the front legs.

8. A work unit as claimed in Claim 7 in which the handrail, in its inoperative storage position, lies in front of lower portions of the front legs, but does not obstruct the step.

9. A work unit as claimed in Claim 7 in which the handrail is latched in its operative erect position by engagement of handrail latching means extending between at least one front leg and the handrail.

10. A work unit as claimed in Claim 7 in which the handrail is latched by at least one portion of the seat.

11. A work unit as claimed in Claim 7 in which the handrail comprises a U-shaped member having the free ends of its side limbs pivoted to the front legs adjacent their upper ends and in its operative erect position the limbs extend generally parallel to the front legs.

1 2. A work unit as claimed in Claim 6 including a step rail extending between the rear legs.

1 3. A work unit as claimed in any one of the preceding claims in which the vice unit comprises a pair of horizontally extending vice members having flat upper surfaces lying in substantially the same plane to form a working surface, and a pair of spaced vice operating means being operatively connected to at least one of the members to move it with respect to the other member.

14. A work unit as claimed in Claim 6 and as claimed in Claim 1 3 including a pair of top rails extending from front to rear and supporting the vice members, the legs being pivotally connected to front and rear portions of the top rails for movement between an open position and a collapsed position.

1 5. A work unit as claimed in Claim 3 including manually releasable means to retain the unit against folding from its open position.

1 6. A work unit as claimed in Claim 14 and as claimed in Claim 1 5 in which the releasable means comprises co-operating latching members on at least one of the front legs and the vice unit.

1 7. A work unit as claimed in any one of the preceding claims in which the seat is capable of folding to expose the vice unit, and in its unfolded condition forms a tool tray.

18. A work unit as claimed in Claim 1 7 in which the tool tray blocks access to the step.

19. A work unit as claimed in Claim 1 7 in which the tool tray is situated at a lower level than the vice unit.

20. A unit as claimed in any one of Claims 1 7 to 1 9 in which the tool tray is situated at a lower level than the vice unit.

21. A unit as claimed in Claims 13 and 1 7 in which the vice operating means have operating handles which are positioned on the side of the unit opposite to that at which the tool tray is situated.

22. A unit as claimed in Claim 1 3 in which the vice members have to be separated to enable the seat to cover the vice unit.

23. A unit substantially as described herein with reference to Figs. 1 to 10 or Figs. 11 to 21 of the accompanying drawings.