Field of the Invention

The present invention relates to a safety light, for example for indicating the presence of a fixed or temporary structure.

Background

There are often safety risks in dark and/or poorly lit environments, for example in which vehicles are operated and/or pedestrians are moving around fixed and/or hazardous structures. For example, in mine sites, vehicles are often driven at night on roads that are poorly lit. Fixed and/or temporary structures, such as bollards, posts, and the like can be located near the edge of the road, and these can be difficult for vehicle operators to see in periods of darkness, and/or low-light ambient conditions, particularly at night time. Similarly, where mine site operators are working at night around areas that contain hazards, there is a risk that the operators can stray into areas that require particular personal protective equipment, and/or areas in which access is restricted to a specific group of people. Accordingly, it is desired to address the above, and/or at least provide a useful alternative.

Summary of the Invention

The present invention provides a safety light comprising a light emitting module, and a mounting housing that:

defines a region within which the light emitting module is disposed;

is made of a translucent material, such that light emitted from light emitting module can pass through the housing; and

includes one or more securing elements associated with the housing, the securing elements being for use in releasably and/or fixedly attaching the safety light to an article.

Preferably, the region is an internal cavity.

In certain embodiments, the light emitting module includes a rigid outer body, and the internal cavity includes a tapered throughway that is shaped such that the outer body can be passed into the throughway in a first direction, and the taper inhibits the outer body passing through the throughway.

Preferably, the mounting housing is made of a material that is at least partly resiliently deformable.

In some embodiments, the mounting housing can include an annular base, and the internal cavity can include one or more well portions that are each co-axial with the throughway and have an outer diameter that is larger than that of the throughway.

Preferably, the internal cavity includes three well portions, and the outer diameters of the well portions increase relative to the or each well portion that is closer to the throughway. In some alternative embodiments, the mounting housing includes an annular base, and the internal cavity is a void. In such embodiments, the mounting housing can include light diffusing elements. The light diffusing elements can be optical prisms. In one form, the light diffusing elements are diffusing ribs that are arranged on an internal surface of the mounting housing.

In some embodiments, the securing elements include one or more apertures that extend through the housing, wherein the housing can be secured to an article by extending fasteners through the apertures such that the fasteners engage the article. The apertures can be parallel to the throughway. Preferably, each aperture includes a counterbore such that the head of a fastener can be recessed within the respective aperture. In such embodiments, the article can be a bollard or post that is embedded in the earth.

In some embodiments, the safety light further comprises a cap member that includes:

a plate member having mounting holes,

a sleeve that projects from the plate member, the sleeve including at least one transverse hole such that the sleeve can be located over a top portion of a post, and a first fastener passed through the at least one transverse hole to secure the safety light to the post, and the safety light further includes second fasteners, wherein the mounting housing can be attached to the plate member by aligning the apertures in the mounting housing with the mounting holes in the plate member, and passing the second fasteners through the aligned apertures and holes.

Alternatively, the securing elements includes a sleeve that is integral with the mounting housing, the sleeve including at least one transverse hole, whereby the sleeve can be located over a top portion of a post, and a fastener passed through the at least one transverse hole to secure the safety light to post.

Preferably, the sleeve has a cross section that is shaped to locate on a star picket.

In some embodiments, the securing elements include connectors that are integrally formed in the mounting housing, and the safety light further includes at least one elongate fastening element that connects with the connectors, whereby the at least one fastening element can be passed around the article to releasably secure the safety light to the article.

In certain embodiments, each of the connectors defines an aperture, and the at least one elongate fastening element is configured to pass through each aperture.

The light emitting module can further include an electronic circuit with a light emitting device, and the electronic circuit is disposed within the rigid outer body. The electronic circuit can include an electrical storage device for providing electrical power to the light emitting device. The electrical storage device can be a rechargeable battery.

The electronic circuit can include an energy harvesting device, and electrical energy harvested by the energy harvesting device is supplied to the electrical storage device. The energy harvesting device can be a solar cell.

Preferably, the rigid outer body is made of a material that is at least translucent. More preferably, the rigid outer body is sealed against water ingress. In some embodiments, the rigid outer body may also be hermetically sealed. The present invention also provides a mounting housing for assembly with a light emitting module to provide a safety light, the mounting housing:

defines a region into which the light emitting module is to be disposed;

is made of a translucent material, such that light emitted from the light emitting module can pass through the mounting housing; and

includes securing elements associated with the housing, the securing elements being for use in releasably and/or fixedly attaching the mounting housing to an article. The present invention also provides a light unit comprising:

an outer body made of a translucent material that is permanently hermetically sealed;

an electrical storage device; and

an electrical circuit that has an energy harvesting device, one or more light emitting devices, and a magnetic switch that is normally closed, the electrical circuit being configured such that electrical energy harvested by the energy harvesting device can be supplied to the electrical storage device, and such that electrical energy can be supplied to the light emitting devices,

wherein the electrical storage device and the electrical circuit are embedded within the outer body, and wherein when the magnetic switch is within a magnetic field that exceeds a predetermined magnetic field strength, the magnetic switch is open.

In some embodiments, the light emitting devices include a first light emitting device that is arranged to emit light in a first direction with respect to the outer body, and a second light emitting device that is arranged to emit light in a second direction that is opposite to the first direction.

In some embodiments, the electrical circuit further includes a light sensing switch that is closed when the sensed light level is below a predetermined light level, and is open when the sensed light level is above the predetermined light level.

In certain embodiments, the energy harvesting device can be a solar cell. In such embodiments, the electrical circuit can be configured such that when the output voltage of the solar cell is below a predetermined threshold, electrical energy is supplied to the light emitting devices. Preferably, a portion of the outer body is shaped to define an optical lens that directs light contacting the outer surface of the lens towards the solar cell.

The body can be formed of an outer shell that is filled with a settable plastic after the electrical storage device and electrical circuit have been disposed in the outer shell. Thus, the light unit can be permanently hermetically sealed.

Preferably, the light unit is a light emitting module for assembly with a mounting housing to form a safety light, as previously described.

The present invention also provides a safety system for a mining site, the system comprising two or more sets of safety lights, the safety lights in each set having a colour and/or strobing pattern that is unique to that set, and wherein each set is representative of a predetermined warning, hazard, or operating requirement within the mine site.

Brief description of the drawings

In order that the invention may be more easily understood, embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 : is a top view of a safety light according to a first embodiment of the present invention;

Figure 2: is a perspective view of the safety light of Figure 1 ;

Figure 3: is a partially assembled view of the safety light of Figure 1 ;

Figure 4: is a lower perspective view of the housing of the safety light of

Figure 1 ;

Figure is a perspective view of the safety light of Figure 1 attached to bollard;

Figure 6: is a schematic plan view of the housing of Figure 1 ;

Figure 7: is a cross section view of the housing as viewed along the line X-X in

Figure 6;

Figure 8: is an upper perspective view of a housing for a safety light according to a second embodiment of the present invention;

Figure is a lower perspective view of the housing of Figure 8;

Figure is a bottom view of the housing of Figure 8; Figure 1 1 : is a cross section view of the housing as viewed along the line Y-Y in Figure 10;

Figure 12: is an lower perspective view of a housing for a safety light according to a third embodiment of the present invention;

Figure 13: is a bottom view of the housing of Figure 12;

Figure 14: is a perspective view of a safety light according to a fourth embodiment of the present invention, the safety light being attached to the top of a star post;

Figure 15: is a view of the safety light and star post of Figure 14, showing the light emitting module in an illuminated state;

Figure 16: is a partially assembled view of the safety light of Figure 14;

Figure 17: is a lower perspective view of the cap member of the safety light of

Figure 16;

Figure 18: is an exploded view of the safety light and star post of Figure 14; Figure 19: is a perspective view of the housing of Figure 12 and a strap for securing to a scaffold tube;

Figure 20: is an end view of the housing, strap and scaffold tube of Figure 19; Figure 21 : is a front view of the housing of Figure 12 and a strap for securing to a temporary bollard;

Figure 22: is a side view of the housing and strap of Figure 21 ;

Figure 23: is a front view of the housing and strap of Figure 21 attached to the top of a temporary bollard;

Figure 24: is a perspective view of the safety light of Figure 1 , the safety light being attached to the top of a temporary bollard;

Figure 25: is a schematic side view of a light emitting module according to a fifth embodiment of the present invention, showing the light emitting module in a deactivated state;

Figure 26: is a schematic side view of the light emitting module of Figure 25, showing the light emitting module in an activated state; and Figure 27: is a schematic plan view of a safety system for a mining site in accordance with sixth embodiment of the present invention. Detailed description

Figures 1 to 3 show a safety light 10 according to a first embodiment of the present invention. The safety light 10 includes a light emitting module 12, and a mounting housing 14. As shown most clearly in Figure 3, the housing 14 defines a region, which in this embodiment is in the form of an internal cavity 16, into which the light emitting module 12 is to be disposed. The housing 14 is made of a translucent material such that light emitted from the module 12 can pass through the housing 14. In addition, the housing 14 has securing elements that are for use in releasably and/or fixedly attaching the safety light 10 to an article. The securing elements of this embodiment are described in further detail below.

For the purposes of this specification, the term "translucent" is to include "transparent" and "semi-transparent". Thus, the safety light 10 can be secured to an article and, at least during periods of low light and darkness, the module 12 activated to emit light, which can pass through the housing 14. In one example that is illustrated in Figure 5, the safety light 10 can be secured to the top of a bollard B. In other words, the safety light 10 can be retrofitted to a pre-existing bollard; for example, after the bollard has been installed in the ground. In this example, light that is emitted radially outwardly of the module 12 - and thus also radially outwardly of the bollard B - passes through housing 14 and is visible to people nearby the bollard B. This has the advantage of increasing the likelihood of the presence of the bollard B being recognized, which reduces the likelihood of equipment being damaged, and/or people being injured.

The housing 14 is shown in greater detail in Figures 4, 6 and 7. As is particularly evident from Figure 7, the internal cavity 16 includes a throughway 18, which is tapered such that the throughway 18 narrows towards the upper side of the module 14. In Figure 7, the diameter of the throughway 18 at the upper side of the module 14 is indicated by reference numeral d{, and the diameter of the throughway 18 that is closest to the base of the module 14 is indicated by reference numeral d ₂ . By virtue of the tapering, d ₂ > d^ Furthermore, cross sections of the throughway 18 are circular, such that the throughway 18 has a generally frustoconical shape.

The light emitting module 12 has a rigid outer body 20, which in this embodiment is cylindrical. The housing 14 is made of a material that is resiliently deformable, relative to the outer body 20. The outer body 20 can be passed into the throughway 18 in a first direction, from the base side of the housing 14, as indicated by block arrow A in Figure 3. The taper of the throughway 18 inhibits the outer body 20 passing entirely through the throughway 18. In other words, the module 12 has an interference fit within the throughway 18. Further, the narrowest diameter d-ι of the throughway 18 is such that the module 12 can be disposed within the throughway 18 such that the upper sides of the module 12 and housing 14 are flush with one another.

The housing 14 has an annular base 22. The internal cavity 16 of this particular embodiment further includes three well portions 24, 26, 28 that are each co-axial with the throughway 18. The well portions 24, 26, 28 all have an outer diameter that is larger than that of the throughway 18. Furthermore, the outer diameters of the well portions 24, 26, 28 increase relative to the or each well portion that is closer to the throughway 18. In other words, the outer diameters of the well portions 24, 26, 28 increase with proximity to the base 22. The well portions 24, 26, 28 facilitate locating the safety light 10 on cylindrical objects, such as posts and bollards, of various diameters. Alternatively or additionally, the well portions 24, 26, 28 facilitate locating the safety light 10 on domed surfaces. In the embodiment of Figure 1 , the securing elements is in the form of two apertures 30, 32 that extend through the housing 14. The housing 14, and thus also the safety light 10, can be secured to an article by extending fasteners (not shown) through the apertures 30, 32 such that the fasteners engage the article. As will be appreciated, in this embodiment the fasteners can be threaded fasteners with an external thread that engages with the article, or a complementary internally fastening element associated with article. For example, in the example illustrated in Figure 5 the bollard B is hollow steel, and metal self-tapping screws may be used. As shown in Figure 7, each aperture 30, 32 includes a counterbore in which the head of a fastener can locate. The mounting housing 14 can be made of plastics materials, such as polycarbonate, polypropylene, polyethylene, or exotic plastics (including high performance plastics). The mounting housing 14 can include light diffusing elements that diffuse light passing through the housing. In this embodiment, the light diffusing elements are in the form of voids and/or entrained gas bubbles that assist in diffusing light passing through the housing 14. In some embodiments, the mounting housing includes voids that are formed by inserts that are placed in the injection moulding tool. The use of mould inserts can be advantageous in forming voids that optimally diffuse light passing through the mounting housing.

The light emitting module 12 further includes an electronic circuit (not shown) that is disposed within the rigid outer body. The circuit includes a light emitting device 34, an electrical storage device for providing electrical power to the light emitting device 34, and an energy harvesting device. In this embodiment, the electrical storage device is a rechargeable battery (not shown), and the energy harvesting device is a solar cell 36. As will be appreciated, electrical energy that is harvested by the solar cell 36 is supplied to the battery.

The rigid outer body 20 is at least sealed against water ingress, and in some embodiments, the outer body 20 may also be hermetically sealed. As is evident from Figure 3, the outer body 20 is made of a material that is at least translucent. Thus, the module 12 is a sealed, self-contained unit.

Figures 8 to 10 show a mounting housing 1 14 for a safety light, the housing 1 14 being in accordance with a second embodiment of the present invention. The housing 1 14 is substantially similar to the housing 14 of the safety light 10 of Figure 1. In Figure 8, the features of the housing 114 that are substantially similar to those of the safety light 10 have the same reference numeral with the prefix "1 ".

The housing 1 14 defines a region, which in this embodiment is in the form of an internal cavity 1 16, into which a light emitting module is to be disposed. The housing 114 is made of a translucent material such that light emitted from the module can pass through the housing 1 14. The internal cavity 16 includes a throughway 1 18, which is tapered in the same manner as the throughway 18 of the housing 14. Two apertures 130, 132 extend through the housing 114, and fasteners are to extend through the apertures 130, 132 to secure the housing 114 to an article.

The mounting housing 14 can be made of plastics materials, such as polycarbonate, polypropylene, polyethylene, or exotic plastics. In this embodiment, the light diffusing elements of the mounting housing 14 are optical prisms formed on the internal surface surrounding the cavity 1 16. In particular, the light diffusing elements are linear diffusing ribs 1 19 that each have a generally triangular prism shape, such that light passing through the housing 1 14 is diffused. Figures 12 and 13 show a housing 214 of a safety light, the housing being in accordance with a third embodiment of the present invention. The housing 214 is substantially similar to the housing 14 of the safety light 10 of Figure 1. In Figures 12 and 13, the features of the safety light 210 that are substantially similar to those of the safety light 10 have the same reference numeral with the prefix "2".

In this embodiment, the light diffusing elements of the mounting housing 214 are linear diffusing ribs 219 that each have a generally triangular prism shape.

In this embodiment, the securing elements of the housing 214 of a safety light includes in loops 254, 256 formed with the mounting housing 214. Each loop 254, 256 defines an aperture 230, 232.

The safety light 210 further includes at least one elongate fastening element (not shown in Figures 12 and 13), which can be in the form of one or more straps that can each be passed through the apertures 230, 232. The strap(s) can be passed around the article to releasably secure the safety light to that article.

In this embodiment, the housing 214 includes locating formations to facilitate locating a safety light including the housing 214 on an article. In this embodiment, the locating formations include two notches 260, 262 on opposing sides of the base 222. The notches 260, 262 facilitate locating the housing 214 over the T-shaped handle formed at the upper end of a "T-Top" temporary bollard. The two notches 260, 262 are spaced alternately and equiangularly with the loops 254, 256 around the base 222 of the housing 214. Thus, the housing 214 - and in particular, a safety light that includes the housing 214 - can be retrofitted to a pre-existing portable bollard.

The side walls of each notch 260, 262 are separated by the width of the T-shaped handle, and the base of each notch 260, 262 is arcuate to match the radius of curvature of the T-shaped handle. A commonly used T-Top bollard has a handle with a curved upper surface that is cylindrical with a diameter of 140 mm, and in this embodiment the base of each notch 260, 262 has a radius of 70 mm.

The securing of the housing 214 to a T-Top bollard is described in further detail in connection with Figures 21 to 23.

In this embodiment, the locating formations also include four circular arc segments 264, 266, 268, 270 formed in the base 222. The arc segments are shaped to facilitate locating the housing 214 on a cylindrical body, such as a scaffolding tube. In this embodiment, each arc segment 264, 266, 268, 270 is located on a respective side wall of the notches 262, 264. Commonly used scaffolding tube has a diameter of 65 mm, and in this embodiment each arc segment 264, 266, 268, 270 has a radius of 32.5 mm.

The securing of the housing 214 to a scaffolding tube is described in further detail in connection with Figures 19 and 20.

Figures 14 to 18 show a safety light 310 in accordance with a fourth embodiment of the present invention. The safety light 310 is substantially similar to the safety light 10 of Figure 1. In Figures 14 to 18, the features of the safety light 310 that are substantially similar to those of the safety light 10 have the same reference numeral with the prefix "3".

The safety light 310 includes a cap member 340 that has a plate member 342 with mounting holes 344, 346. The plate member 342 also has a sleeve 348 that projects downwardly from the plate member 342. The sleeve 348 has a pair of transverse holes 350, 352, such that the sleeve 348 can be located over a top portion of a post S, and a first fastener (not shown) passed through the transverse holes 350, 352 to secure the safety light 310 to the post S. The safety light 310 further includes second fasteners 345. The mounting housing 314 is to be attached to the cap member 340 by aligning the apertures 330, 332 in the mounting housing 314 with the mounting holes 344, 346 in the plate member 342, and passing the second fasteners 345 through the aligned apertures and holes.

The post S is star picket (also known as a "star post", "T-post", or "Y-post"), which has holes formed at intervals along one "arm" of the post S. As is evident from Figure 17, the sleeve 348 has a cross section that is shaped to locate over the end of the post S. The transverse holes 350, 352 align with one of the holes in that arm. In an alternative embodiment of a safety light that is substantially similar to that of Figures 14 to 18, the sleeve can be integrally formed with the mounting housing. In some of these alternative embodiments, the light emitting module can be co-moulded with the mounting housing and sleeve. Alternatively, the mounting housing and cap member can have complementary interlocking features, so that the light emitting module is positioned within the internal cavity of the mounting housing, and then mounting housing connected to the cap member. Figures 19 and 20 show the housing 214 together with a pair of straps 258a, 258b that each pass through a respective one of the apertures 230, 232. The four arc segments 264, 266, 268, 270 are located on the outer cylindrical surface of an article, which is a section of scaffolding tube U in this example. As indicated in Figures 19 and 20, in use of the safety light including the housing 214 and straps 258a, 258b, the straps 258a, 258b are passed around the tube U to releasably secure the safety light the tube U. The straps 258a, 258b can include complementary sections of hook and loop fastener materials to facilitate securing the strap 258, and thus the safety light to the tube U.

In some alternative embodiments, the elongate fastening element can be a loop of elastomeric material, such as rubber, synthetic rubber material, or similar. In such embodiments, the housing can include securing pins that project outwardly, and the strap can include holes that locate over the securing pins. In some alternative embodiments, the strap may be self locking to inhibit release of the strap and removal of the safety light. To this end, the strap and/or housing may include an integrated gear rack, and on one end a ratchet within a small open case. In one example, the strap and housing may cooperate in the manner of a cable tie with the gear rack disposed on the strap, and the ratchet formed in housing.

Figures 21 and 22 show the housing 214 together with a pair of straps 258c, 258d that each pass through a respective one of the apertures 230, 232. Each of the straps 258c, 258d is forked to have two free ends 270a, 270b, 270c, 270d. As indicated in Figure 23, the straps 258c, 258d can include complementary sections of hook and loop fastener materials to facilitate securing the straps 258c, 258d, and thus the safety light to an article. In the example shown in Figures 23 and 24, the free ends 270a, 270b, 270c, 270d of the straps 258c, 258d are to be wound around the handle of a "T-Top" temporary bollard T and secured to one another, so as to secure the housing 214 to the bollard T. Figures 25 and 26 show a light emitting module 412 according to a fifth embodiment of the present invention. The light emitting module 412 includes an electronic circuit that includes an electrical storage device, and at least one light emitting devices. In this embodiment, the electrical storage device is a rechargeable battery 472, and the circuit includes a first light emitting diode (LED) 436 that is oriented to emit light generally upwardly and radially of the module 412. In addition, a second LED 474 is oriented to emit light generally downwardly and radially of the module 412. When the module 412 is assembled in a mounting housing - for example, housing 214 - as previously described, the second LED 474 emits light into the internal cavity 216. As will be appreciated, the second LED 474 together with the ribs 219 facilitate visibility of the safety light from side aspects.

The electronic circuit includes an energy harvesting device in the form of a solar cell 436 that harvests energy for supply to the battery 472. The module 412 has an outer body that includes an outer shell 420. An optical lens 476 is formed by the outer shell 420, the lens 476 being shaped and positioned to direct light contacting the outer surface of the lens 476 towards the solar cell 436. Thus, the amount of sunlight that reaches the solar cell 436 is maximized, and the loss of charging voltage with decreasing angle between the sun and the plane of the solar cell 436 is reduced.

As shown schematically in Figures 25 and 26, the battery 472 and the components of the electronic circuit are embedded within the outer body. To this end, the battery 472 and the electronic circuit are positioned in the shell 420, and the shell 420 is filled with a settable plastic 478. Thus, the electronic circuit is hermetically sealed such that ambient air, moisture and dust cannot contact the electronic circuit.

The electronic circuit includes a magnetic switch 480 that is operable to isolate the battery 472. As shown in Figure 25, when a magnet M is placed in proximity to the switch 480, the switch 480 is open and the light emitting module 412 is in a deactivated state. However, the switch 480 is normally closed such that when the magnet M is removed the switch 480 closes and the light emitting module 412 is in an activated state, as shown in Figure 26. The electronic circuit also includes a light sensing switch 482, that is closed when the ambient light level is below a predetermined level, and is open when the ambient light is at or above the predetermined level. ln some alternative embodiments, the electrical circuit can be configured such that when the output voltage of the solar cell 436 is below a predetermined threshold, electrical energy is supplied to the LEDs 436, 474. In such embodiments, the light sensing switch may be omitted.

As will be appreciated, the supply of electrical energy is also governed by the state of the magnetic switch 480.

Figure 27 shows schematically a safety system 500 for a mining site S. The system 500 includes two or more sets of safety lights, such as the safety lights of the previously described embodiments. In the illustrated example, the system 500 has four distinct sets 501 , 502, 503, 504 of safety lights. The light modules of the safety lights in each set have a colour and/or strobing pattern that is unique to that set. Each set is representative of a predetermined warning, hazard, or operating requirement within the mine site S.

The safety lights within a set may be placed at an access point for a particular area. Alternatively or additionally, safety lights of a set may be placed on, or nearby to, particular hazards. Further, the safety lights of a set may be placed at intervals around the perimeter of a particular area.

In one non-limiting example, the system 500 is arranged such that the sets 501 , 502, 503, 504 are representative of:

• immovable objects that may be damaged, and/or cause damage, by impact with movable objects - by the safety lights in the first set 501 being disposed on each of the immovable objects;

• areas of that require a predefined minimum level of person protective equipment (PPE), for example, by electrical works, possible exposure opt hazardous materials, or works at elevated levels - by the safety lights in the second set 502 being disposed at access points to those areas;

• areas to which access is restricted to designated persons, for example, due to works that necessitate access being restricted to persons with certain levels of training - by the safety lights in the third set 503 being disposed at access points to those areas; and

· areas to which access is prohibited to all personnel, for example, due to highly hazardous activities such as rock blasting within a mine site - by safety lights in the fourth set 504 being disposed at access points to those areas, and/or at intervals around the perimeter of those areas.

As will be appreciated, a safety light in accordance with embodiments of the present invention can be readily secured to an article - including permanent and temporary structures, objects and other installations - at any time after that article has been erected/installed. Accordingly, an article that is considered to be hazardous due to its placement and/or due to proximity to other objects can have a safety light retrofitted to the article to increase its visibility in low-light conditions.

Although embodiments have been illustrated with bollards and scaffolding tubes, it will be appreciated that alternative embodiments can be secured to other articles and/or structures, including permanent and temporary road traffic barriers, fences, gates and doors, wall surfaces, tunnel walls and roofs, overhead structures with limited clearance, traffic cones, etc.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.