WO2013122537A1

WO2013122537A1 - Apparatus and method for marking of reference dots

Info

Publication number: WO2013122537A1
Application number: PCT/SE2013/050129
Authority: WO
Inventors: Jan-Olof OLSON; Per-Ove SKÖLD
Original assignee: Olson Jan-Olof
Priority date: 2012-02-17
Filing date: 2013-02-15
Publication date: 2013-08-22
Also published as: EP2825838A4; EP2825838A1

Abstract

This invention relates to a handhold pocket-sized marking apparatus, comprising a housing (1), a reference wheel (3), rotatably attached to the housing (1) by means of a bearing (33) having one part (33B) fixed to the housing and the other part (33A) fixed to the wheel (3), a rotatable member (6) within said housing arranged to be rotated by means of said wheel (3), an electronic measurement arrangement (10,11) connected to said rotatable member (36) and an electronic control unit (200) registering and handling input data from said measurement arrangement (10,11), wherein, a marking holder member (2) is arranged to protrude through an opening (102) in said housing (1), a marking member (20) arranged at one end of said marking holder (2) and an activation mechanism (5A, 5B, 6, 7, 9) arranged to move said marking holder (2) from an inactive to an active position for providing a marking, wherein said activation mechanism (5A, 5B, 6, 7, 9) is electronically controlled and arranged to include interconnecting means (6), which in an inactive mode disables said marking holder (2) to move and which in an active mode interconnects with said rotatable member (10) for movement of said marking holder (2).

Description

APPARATUS AND METHOD FOR MARKING OF REFERENCE DOTS

TECHNICAL FIELD

This invention relates to a handhold pocket-sized marking apparatus, comprising a housing, a reference wheel arranged to roll along a surface to marked and/or measured, said reference wheel being rotatably attached to the housing by means of a bearing having one part fixed to the housing and the other part fixed to the wheel, a rotatable member within said housing arranged to be rotated by means of said wheel, an electronic measurement arrangement connected to said rotatable member and an electronic control unit registering and handling input data from said measurement arrangement.

TECHNICAL BACKGROUND

In connection with construction work it is essential that correctness may be applied regarding measurement, e.g. fixation of support members in accordance with a predefined pattern. In many situations a plurality of items have to be fixedly positioned (e.g. by means screw and nail) with a predefined spacing. There exist many different utilities that are meant to facilitate marking of reference dots in a more efficient manner than the traditional way of using a rule and pen. However, existing such utilities do have drawbacks regarding one or more aspects.

For instance US 2005/0178019 discloses a marking system having a coiled measuring tape arranged in a housing with an incorporated marking device. By means of manual power a marking is achieved that may be read on the measuring tape. Also US 5416978 shows a marking system based on the use of coiled measuring device.

US 2007/0124952 and US2003/0037448 discloses an electronic marking and measuring device which can measure the length or distance along both planar and non-planar surfaces, using a wheel that rolls along the surface to be measured. The wheel is used to electronically measure and to encode the distance of the wheel rotation.

US 2009/0064527 discloses a marking and measuring device calibrated to measure and mark surface at regular predetermined intervals. The device does not present a handheld, portable apparatus but instead a large bulky structure that comprises a frame with a handle and with a support member intended for a marking substance such as an aerosol paint container, resulting in limited use, i.e. merely on horizontal surfaces. The frame further comprises two wheels that rotates relative the surface to be measured, a measurement mechanism that is in communication with actuating means wherein the measurement mechanism sends a signal to the actuating means which in turn sends a signal to an actuator causing marking substance to dispense from the container and onto the surface.

SUMMARY OF THE INVENTION

It is an object to provide an improved device and method for marking, which is achieved by means of the novel concept as defined in claim 1. Thanks to the invention marking utility is provided that in a reliable manner enables fulfilment of marking needs that may be used within a wide variety of construction work and that enables easy use and also enable a desired compactness.

According to further aspects of the invention:

- the interconnecting means is arranged to interconnect by means of the friction, which provides the advantage that total flexibility is obtained in relation to when the interconnection between the inner rotating member and the interconnecting device is to be obtained.

- the rotatable member includes a disc and the interconnecting means includes friction elements arranged to clamp into frictional engagement with the disc in its active mode, which provides a reliable design for obtaining interconnection, the disc includes regularly displaced sensor elements arranged to interact with a sensor device to measure the rotation movement of the disc, which provides a safe and cost-efficient concept to measure the positioning of the reference wheel and thereby also the distance that the wheel has moved, resulting in a cost- efficient manner of facilitate accurate control for positioning markings reference dots on desired locations.

- the rotating member, preferably in the form of a disc, is fixedly attached to an inner rotating part that is arranged to rotate synchronically with the reference wheel, which provides the advantage that it may eliminate any need of intermediate transmission elements in the form of gearings, i.e. providing a cost- efficient design.

- the activation mechanism includes an arm rotatably arranged within said housing having said marking holder and said interconnecting means attached thereto, which furthermore facilitates a cost-efficient design of the apparatus. - the use of a lever mechanism interconnecting the rotatable arm and the marking holder, which facilitates a protected positioning of the marking pen in its inactive position, thanks to enabling further lateral movement.

- the activation mechanism includes at least one electronically activated voice coil for activation of said interconnecting means, which enables many advantages, e.g. low cost and low weight.

- the use of a control unit comprising processor means and memory storage means (in combination with appropriate software) enabling use of prestored parameters to initiate active mode, which provides the advantage that the apparatus may be pre-programmed with a variety of the marking patterns, that the user may easily get access to. For instance such pattern may be chosen in relation to actual national regulations regarding "c-c" sent distances for different building structures etc., enabling the user to easy achieve accurate markings in connection with different constructions.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be described in more detail with reference to the figures, wherein:

Fig. 1 is a sectioned, vertical, cross-sectional frontview of a preferred embodiment in a semi active mode, having the marking marking holder in a ready to strike position/Fig. 1 A is a from above seen, cross-sectional view of the

interconnecting mechanism,

Fig. 2 is a differently sectioned, vertical, cross-sectional frontview of the embodiment of Fig. 1, along lines II - II in Fig. 3, showing the marking holder in inactive mode,

Fig. 3 is a cross sectional view along lines III - III in Fig. 2,

Fig. 4 shows the marking pen and accessories

DETAILED DESCRIPTION

In Figs. 1-3 there is shown an apparatus in accordance with a preferred embodiment according to the invention, comprising a housing 1. The size of the housing is in the preferred embodiment pocket-sized, i.e. it will easily fit into a pocket of a user, e.g. having a cross sectional maximum extension that is less than 15 cm and a thickness of normally less than 5 cm preferably the height and weight thereof is substantially the same, within the range of 8-12 cm. Within the housing 1 there is arranged a marking holder 2 having a front part protruding through an opening 10 of the housing 1. At the front end of the marking holder 2 there is arranged a marking pen 20, by means of some kind of easily manipulated attachment 21, e.g. a bayonet fixation, or any other snap in attachment. Thanks to this attachment 21 the marking pen 20 may be easily exchanged, e.g. in connection with wear or exchange for another colour. At the back side of the housing 1 (see Fig. 3) there is also arranged a reference wheel 3 having a diameter that generally corresponds to the height/width of the housing 1.

Preferably the housing 1 is divided into two halves 1 A, IB, wherein one half IB is used for fixing of a bearing 33. Accordingly the wheel reference 3 has a periphery that at least at some locations is positioned adjacent but inside of the other parts of the housing. At the contact end i.e. lower end of the apparatus the reference wheel 3 has its periphery 30 protrude outside of the lower end 101 of the housing 1. Accordingly the lower periphery 30 of the reference wheel 3 will come in contact with the surfaces on to which the apparatus is positioned. The reference wheel 3 has an axis of rotation 8 that is positioned substantially centrally across the housing 1. The reference wheel 3 is arranged with a stubshaft 31 that protrudes from one side of the reference wheel 3 into a bearing 33, i.e. into the inner half 33 A (the bearing seat), of the bearing 33. The bearing has its outer half 33 B fixed to the backside IB of the housing by means of a ring 34 that is clamped (by screws 35) in fixed contact with the housing 1 and the outer bearing half 33B. The inner half 33 A is clamped (by screws 37) to an inner rotating part 36 within the housing. Also the reference wheel 3 (with stubshaft 31) is clamped thereto by means of the same screws 37. Accordingly when the apparatus is positioned with its contact side 101 opposing a surfaces S and is moved, the reference wheel 3 will rotate around the centre of rotation 8, and all details affixed to the inner rotating part 36 within the housing 1 will then also rotate. Adjacent the bottom 101 of the housing 2 there are arranged two support wheels 13, 15 which together with the large wheel 3 provides for three support points, that enables a balanced and steady handling of the apparatus when moving it along a surface.

The marking holder 2 is moveably arranged within the housing 1, and comprises one inner portion 2B and one outer portion 2A. The movement of the marking holder 2 is partly achieved by means of the reference wheel 3, for this purpose there is a rotatable arm 7 having its pivot axis coaxial with the axis 8 of the reference wheel. At the lower end 7B of the arm 7 there is arranged a parallel lever mechanism 9 which in turn has the marking holder 2 attached therefor. At the other end of the arm 7 there are attached interconnecting members 6, which when active will allow the reference wheel to transmit its rotationable movement to the arm 7, thereby moving the marking holder 2, from an inactive position to an active position. The arm 7 is rotatably arranged within the housing 1 around the same axis 8 as the reference wheel, but rotatable in relation to the inner rotating part 36.

It is shown that the arm 7 preferably is Z-shaped having an upper part 7A directed substantially vertically. The intermediate portion 7C extends transversely and downwardly, in order to allow the lower part 7B of the arm 7 to be positioned off centred in relation to the disk 10. Thanks to this positioning the space requirement for the lever mechanism 9 of the marking holder 2 is easily provided for. Further the connecting device 6 may easily be positioned in relation to the disk at a location where forces due to gravity acting on an interlocking member 60 may easily be balanced as seen in Fig. l . The upper portion 7A of the arm 7 consists of one solid part, whereas the lower part 7B of the arm 7 comprises one inner portion and one outer portion 72.

Between these portions 71, 72 there are arranged distance elements 73. The arrangement of the lower part 7B of the arm 7 provides for a rigid design that enables reliable and precise positioning of the second voice coil 5B and the lever mechanism 9. Further Fig 3 shows that there is a protective cap 104 that encloses the upper portion of the reference wheel 3, which enables the user to grab around the housing 1 and the cap 104 to firmly grip the apparatus.

According to a preferred embodiment of the invention the interconnection between the arm 7 with the lever mechanism 9 and the movement of the wheel 3 is achieved by means of friction. In a preferred embodiment that interconnection is achieved by an activation mechanism comprising a friction element 60 arranged in the upper part 7A of the arm 7, which may interact with a rotating disc 10 that is affixed to the central rotating part 36. When the friction elements 60 is moved into contact with the disc 10 it will interlock therewith, to thereby allow the arm 7 to rotate together with the disc 10/reference wheel 3. A mechanical deactivation device 61, is fixed within the housing, which device 61 includes a protruding pin 62 that when contacting the friction element 60, will force it out of contact with the disc 10 thereby freeing the arm 7. Accordingly this mechanism allows the marking holder 2 to move between an inactive and active position. Fig.1 A shows the principles used for the connecting mechanism 6 according to the invention. As can be seen in Fig.2 there is an opening 75 in the upper part 7A of the arm 7. Within this opening 75 there is ranged a U-shaped floating holder 64', e.g. a floating yoke. The holder 64 is arranged with the one interface 64 having an angled surface arranged to cooperate with the friction element 60, preferably cylindrical to achieve self-locking of the element in between the angled surface 64' and the disc 10. Thanks to the use of a floating yoke relatively large tolerances may be used, i.e. enabling cost efficient production. Further the arm also has attachments devices 76 that hold one activation pin 79 and a deactivation pin 77. Spring elements 78 are arranged onto the arm 7 in order to keep the friction element 60 in a non-locking position. Only when the activation pin 77 is hit by the plunge of the voice coil 5A the friction member 60 is moving into locking contact between the inner wall 64a and the disk 10 thereafter the interlocker situation will be maintained until the deactivation pin 77 hits against the end stop pin 62.

An activation mechanism 5A is positioned within the housing to allow for activation of the friction member 6, by means of a plunge 50 that upon activation will force the friction element 60 into contact with the disc 10. Preferably this activation mechanism 5A is the form of a voice coil, allowing mere electronic activation and also providing low weight and extremely quick action. The lever mechanism 9 enables a downward movement of the marking holder 2,. i.e. allowing the marking pen 20 to get in contact with the surfaces. For the activation of the leaver mechanism 9 there is a further solenoid like device 5B, preferably also in the form of voice coil, that when activated will affect the lever mechanism 9 to make a desired movement, both upwardly and downwardly of the marking holder 2. In order to eliminate dirt from entering into the housing 1 there is a preferably resilient, protective bellow 14 around the marking 2, covering the opening 102.

Both the second voice coil 5B and the first voice coil 5A need to be activated in connection with every marking that should be delivered. A further purpose of the second voice coil 5B is to allow the marking pen 20 to be positioned in a protective cap 22 in connection with non-activity during a relatively long time, i.e. to avoid drying of the marking pen 20. Accordingly, when the apparatus is in use the second voice coil 5B, via the lever mechanism 9, will keep the marking pen 20 uplifted a distance from the protective cap 22 (se Fig. l) Hence the second voice coil 5B needs to be activated prior to activation of the first voice coil 5 A, and normally it will not be moved into its inactive position (into protective cap 22) during the use of the apparatus under a marking sequence, since that final downward movement will be programmed to take place after a relative long time period, e.g. 1 minute. Further it is shown in Fig. 2 a preferred embodiment where magnets 216A-C are used to minimize power need for the second voice coil 5B. There is one magnet in the outer portion 2A of the marking holder 2 and two magnets 216B, C fixed in the housing IB. A lower magnet 216C for keeping the pen 20 within the protective cap 22 and an upper one 216B assisting in keeping the marking holder in its active position. As a

consequence the second voice coil 5B merely has to be active when moving the marking holder to and from the protective cap 22, and further also during the marking

movement. The control system 200 of the apparatus includes the disc 10 which in cooperation with a sensor device 11 enables exact detection of the position of the disc 10/wheel 3. In a preferred mode of detection it includes the to use a wheel 10, provided with teeth 10A at its periphery and an optic sensor device 11, that registers the movement of the teeth 10A (in a known manner). Preferably the sensor device 11 includes a plurality of sensor elements 110A, HOB, preferably in the form of photo cells, positioned with varying angular distance in between that will enable reliable and accurate measurement and also to detect the direction of rotation of the disc 10. The signals from the sensor device 11 are used within the control unit 200 that also comprises a processor. The processor (in a known manner, in combination with appropriate software and hardware) handles input data for accurate activation of the solenoid devices 5A, 5B at desired positions.

Furthermore there is a display 4 and in connection therewith an input interface, (not shown, e.g. touch screen) by means of which the user may easily and flexibly decide what kind of intervals/pattern that should be used for the marking. The central unit 200 may also have prestored a number of predefined intervals, e.g. standard "c-c" measure for each certain kind of support member in connection with constructing a house.

Furthermore instead of using magnets for the marking head 20 to position it in desired end position, there may be arranged springs (not shown) allowing the marking head 20 to return into rest within the protection cap 22.

When using the apparatus the user first activates the control unit 200 (e.g. battery powered) whereby the display 4 will be lit. Preferably a touch screen (not shown) is used to enable input for delivery of a desired marking/pattern. Preferably there is a preprogrammed menu system wherein the user easily may choose between different preinstalled marking patterns, e.g. different preinstalled "c-c" distances. Alternatively the user may give direct input by pressing buttons to program the control unit 200 of the apparatus to deliver markings at desired intervals. Preferably this is achieved by using a software that will assist the user to give input in a correct manner, as is known per se in connection with many software programs. Thanks to the electronic activation also irregular patterns may be achieved, e.g. two nearby markings at certain intervals. Once the desired settings have been finalized the user merely puts the marking apparatus 1 in contact with the surface S that is to be marked in an appropriate starting position. Preferably the apparatus is arranged with a reference line (or light, not shown) that is intended to be positioned to coincide with a start marking on the surface S (which preferably is applied manually, e.g. by means of a pen). Preferably the rear end of the housing 1 is used for a reference line and the software programmed to deduct the distance to the marking pen 20 for the first marking. Thereafter the user merely moves it along the surface S. As soon as the housing 1 is moved forward the reference wheel 3 will start to rotate and thereby also the disc 10, whereby the sensor device 11 will sense the movements and transmit distance input data to the control unit 200, which registers the exact movement of the reference wheel 3, enabling accurate calculation of the distance that have been moved in relation to the last marking. A start button (not shown) may be used that is pressed shortly before a marking movement , and also to activate the second voice coil 5B to pull/pivot the marking holder 2 out of its resting position. As soon as the control unit 200 has registered a pre-set distance (i.e. pre-set number of signals, corresponding to the desired distance between the markings), it will initiate activation of the first voice coil 5 A that in turn activates the friction member 6, interlocking the arm 7 to the disc 10. Thereby the marking holder starts moving against the surface S within the u-shaped cross opening 103 and at the predefined moment (identified by the sensors) the second voice coil 5B will start a downward pivoting of the holder arm 2, whereby the marking member 20, hits against the surface S to affect a marking dot. Preferably the mechanism is calibrated such that the tip 206 of the marking pen 20 moves a slight distance (e.g. 1-2 mm) below the surface S, which is feasible thanks to using a resilient material. Thereafter pin 62 will deactivate the friction element 60 and by means of spring elements (not shown) the arm 7 and marking holder 2 will return to the inactive positions. The second voice coil 5B performs a return stroke at once, i.e. it does not stop in its front end position, whereby the holder 2 is pivoted upwardly and moved backwards simultaneously.

Meanwhile the signals from the sensor 11 will continue to be transmitted to the control unit 200 in order to prepare for activation at the next location when the desired distance has been obtained. Accordingly the marking process will continue as long as the user moves the marking apparatus. The user will not need any manual triggering nor is there any need for any certain skill to use the marking device, but rather the opposite, anyone may use the marking apparatus to obtain desired markings without any actual teaching or pre-knowledge. In Fig. 4 there is shown a sort of exploded view presenting the details of the front part 2 A of the marking holder and the marking pen 20. As shown the front end 2 A has a stub end 24 intended to be inserted into "corresponding" hole in the inner part 2B of the marking holder 2. Within a through hole 210 at the end of the front part 2A there is a first interface 211, 212, 213, 214 adapted for interfit with the marking pen 20, in the form of inwardly protruding members 211, 212, 213, 214 at opposing positions pair- wise within a limited area of the circumference, to leave a gap 215. Four of the members 212 are positioned adjacent the surface of the front end 2 A and two of them 213, 214 further down into the hole 210, one 214 being resilient and arranged with an edge 214A. The marking pen 20 is arranged with corresponding outwardly protruding members 203, enabling a quick attachment of the marking pen 20, in the marking holder 2, by a 90° rotation, whereby at insertion the members 203 of the pen 20 passes by 212 in the gap 215 whereafter the pen 20 may be rotated, to allow its members 203 to slide in on top of 213, 214 and the recess 203A clicking into attachment with the edge 214A. Further it is shown that the marking pen 20 is formed by a cylindrical casing 204, covered at one end by a membrane 205, wherein there is arranged a capsule 202 including ink (or other printing means), and a front end 201 in the form of a porous rubber tip. Hence, the marking pen 20 forms a capsule that is easily exchanged by means of the quick attachment 21. According to a modified embodiment of the invention the marking arrangement (decribed above) may be exchanged by a marking device that shoots a droplet of marking liquid onto a desired spot of the surface that is to me marked. Hence, instead of a physical transmission device/pen there is used a device that upon activation shoots a droplet of marking liquid to produce the marking dot. As a consequence merely one activation device 5A, 5B may be needed, which device 5 A, 5B upon receipt of a control signal from the control unit 200 is energized to shoot the marking droplet (or droplets), e.g. generally along the known principles of an inkjet printer.

The invention is not limited by what has been described above but may be varied within the scope of the appended claims. For instance the skilled person realises that other means for interconnection than friction may be used to achieve a solution in according to the general principles of the invention, e.g. by means of using a ratchet mechanism, or magnetic interconnection, etc. Moreover it is evident to a skilled person that other means than a rotating disc may be used as the interconnecting parts for the marking holder mechanism, e.g. rotationally a symmetric element of varying form may be used as that interconnecting members. Furthermore it is evident that varying kind of arrangement may be used to sense the displacement/movement of the wheel 3 to accurately measure the distance, e.g. laser arrangement, other optical devices, inductive sensor devices, etc. Further it is evident that in some applications it may be

advantageous to use some kind of gear transmission between the wheel 3 and the rotatable part of the distance sensing arrangement, e.g. choosing a gear transmission that will provide one turn of the rotatable part corresponding to a certain movement of the wheel, e.g. one turn = one millimetre. In such a case the distance measuring

arrangement will form a separate device apart from rotatable member 36. Moreover it is evident that instead of using some kind of arm devices, devices of varying form may be used to provide attachment of the marking holder arrangement and the interconnecting members, e.g. wheel like member. Further it is evident that the basics principles of the invention may be utilised also without the use of a lever mechanism 9 between the marking holder 2 and the rotating arm 7. Further it is realised that also other kind of electrically activated devices may be used than using a voice coil, e.g. small solenoids or piezo electric means. Further it is realised that also other kind of bearings, e.g. slide bearings, instead of ball bearings, may be used as shown. Finally it is foreseen that some kind of damper (not shown) may beneficially be included to soften the hit performed by the marking holder 2, or that the second voice coil 5B is controlled to adapt the movement of the stroke to "soften" the "percussion" transmitted to the housing 1.

Further, for the purpose of sophisticated control of the movement of the voice coils 5A, 5B also MEMS units may be used, e.g. both accelerometers as well as gyrometers. Further, it is realised that the invention may be combined with numerous software applications and electronics, e.g. some kind of wireless transmission device, connected to the control unit, (e.g. GPRS, Bluetooth), e.g. to enable transfer of data to the marking device. For instance such a modification would enable the marking device to obtain remotely stored, data (e.g. CAD drawings) regarding the object to be marked, which in turn may assist in preparing the setup of a subsequent marking procedure.

Claims

Handhold pocket-sized marking apparatus, comprising a housing (1), a reference wheel (3) arranged to roll along a surface to marked and/or measured, said reference wheel (3) being rotatably attached to the housing (1) by means of a bearing (33) having one part (33B) fixed to the housing and the other part (33A) fixed to the wheel (3), a rotatable member (6) within said housing arranged to be rotated by means of said wheel (3), an electronic measurement arrangement (10,11) connected to said rotatable member (36) and an electronic control unit (200) registering and handling input data from said measurement arrangement (10,11), characterized in that a marking holder (2) is arranged to protrude through an opening (102) in said housing (1), a marking member (20) arranged at one end of said marking holder (2) and an activation mechanism (5 A, 5B, 6, 7, 9) arranged to move said marking holder (2) from an inactive to an active position for providing a marking, wherein said activation mechanism (5 A, 5B, 6, 7, 9) is electronically controlled and arranged to include interconnecting means (6), which in an inactive mode disables said marking holder (2) to move and which in an active mode interconnects with said rotatable member (10) for movement of said marking holder (2).

Marking apparatus according to claim ^characterized in that said interconnecting means (6) is arranged to interconnect, at least partly by means of the friction.

Marking apparatus according to claim 2, characterized in that said rotatable member (10) includes a disc and that said interconnecting means (6) includes at least one friction element (60) arranged to clamp into frictional engagement with said rotatable disc (10) in its active mode.

Marking apparatus according to claim 3, characterized in that said disc (10) includes regularly displaced sensor elements (10A) arranged to interact with a sensor device (11) to measure the rotational movement of said disc (10).

Marking apparatus according to any preceding claim, characterized in that said rotating member (10) is fixedly attached to an inner rotating part (36) that is arranged to rotate synchronically with said reference wheel (3). Marking apparatus according to any preceding claim, characterized in that said activation mechanism includes a carrier (7) rotatably arranged within said housing, having said marking holder (2) and said interconnecting means (6) attached thereto.

Marking apparatus according to claim 6, characterized by a leaver mechanism (9) interconnecting said carrier (7) and said marking holder (2).

Marking apparatus according to claim 6 or 7, characterized in that said arm (7) has a pivot centre that is coaxial with the axis of rotation (6) of said reference wheel, and that said marking holder (2) and said interconnecting means are attached to one end each of said carrier (7).

Marking apparatus according to any preceding claim, characterized in that said activation mechanism includes at least one electronically activated voice coil (5 A, 5B) for activation of said interconnecting means (6).

10. Marking apparatus according to any preceding claim, characterized by a control unit (200) comprising processor means and memory storage means enabling use of prestored parameters to initiate active mode.