WO2012107922A1

WO2012107922A1 - Stud detector

Info

Publication number: WO2012107922A1
Application number: PCT/IL2012/000066
Authority: WO
Inventors: Amir Agaipour; Efi BOUMRIND
Original assignee: Amir Agaipour; Boumrind Efi
Priority date: 2011-02-10
Filing date: 2012-02-08
Publication date: 2012-08-16
Also published as: WO2012107922A4

Abstract

A device (10) for detecting an elongated metal object located behind a surface, the device comprising: a housing (24) having a substantially smooth contact face, a magnet (30) fixedly received within the housing (24) and configured for attracting the housing (24) to the surface and staying in contact with said surface, a marking arrangement (41) received within the housing (24) and at least partially projecting from said contact face and configured for generating a visible mark on said surface when the device (10) is displaced along the surface and a pulling member (50) articulated to the housing (24) for displacing the device (10) along an expected orientation of the metal object.

Description

STUD DETECTOR

FIELD OF THE INVENTION

This invention relates to a detector for detecting metal objects extending behind surfaces. Such a detector is often referred to in the art as a "stud detector", that being one of its primary uses.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application claims priority from and is related to U.S. Provisional Patent Application Serial Number 61/441,419, filed 10 February 2011, this U.S. Provisional Patent Application incorporated by reference in its entirety herein.

BACKGROUND OF THE INVENTION

Various stud detectors are known in the art, specifically for locating metal studs behind drywalls.

A main drawback of known stud detectors is their unsuitability to easily detect studs above a ceiling, since the method they employ for detecting a stud entails dangling the stud detector in front of a wall.

Another drawback of existing stud detectors is that they do not provide for continuously marking the stud location while progressing along the wall (or ceiling).

SUMMARY OF THE INVENTION

According to the presently disclosed subject matter there is provided a device for detecting an elongated metal object located behind a surface. The device comprises:

(a) a housing having a substantially smooth contact face;

(b) a magnet fixedly received within the housing and configured for attracting the housing to the surface and staying in contact with said surface; (c) a marking arrangement received within the housing and at least partially projecting from said contact face and configured for generating a visible mark on said surface when the device is displaced along the surface; and

(d) a pulling member articulated to the housing for displacing the device along an expected orientation of the metal object.

The term surface as used herein in the specification refers to any surface of a structure of construction, e.g. a surface of a wall, a ceiling or a floor of such structure, cupboards, modular partition elements etc.

The term metal object as used herein in the specification refers to a stud, a pipeline, an electricity or connections wire, screws, nails, profiles etc.

An expected orientation of the metal object is defined as a direction along which a longitudinal axis of the object may extend.

Any one or more of the following non-limited list of optional features may be incorporated in a device according to the presently disclosed subject matter:

• The magnet has an axis of symmetry coaxial with an axis of symmetry of the housing.

• The marking arrangement comprises a pad soaked with marking agent and a marking roller in contact with the marking agent when the marking arrangement is received within the housing, and configured for applying the marking agent on said surface, when in contact therewith.

• The marking roller is configured to rotate about an axis perpendicular to the direction of the expected orientation of the metal object.

• The pad is configured to be extracted from the housing.

• The pad is replaceable.

• The marking agent is any one of an ink, a toner and a powdered material.

• The pulling member is a cord having a first end fixedly attached to the housing, typically at a location on the axis of symmetry of the housing.

According to another aspect of the presently disclosed subject matter there is provided a method for detecting an elongated metal object located behind a surface. The method comprises:

(a) providing a device comprising a housing having a substantially smooth contact face, a magnet fixedly received within the housing, a marking arrangement received within the housing and at least partially projecting from said contact face, and a pulling cord articulated to the housing;

(b) bringing the contact face of the housing into contact with the surface and displacing the device thereover while keeping them in contact;

(c) detecting a location in which the magnet attracts the housing to the surface;

(d) applying a pulling force to the housing by the pulling the cord thereby causing the housing to displace along a direction corresponding to an expected orientation of the metal object, generating thereby a visible mark with the marking arrangement.

The visible mark may extend along the expected orientation of the metal object and, particularly, it may extend along a central axis of the metal object.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carried out in practice, a number of embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:

Fig. 1 is a top perspective view of a device in accordance with the presently disclosed subject matter;

Figs. 2 A and 2B are a top view and a bottom view, respectively, of the device of Fig. 1, showing the marking mechanism;

Fig. 3A is an exploded isometric view of the device of Fig. 1;

Fig. 3B is a side view of Fig. 3 A;

Fig. 4 is an exploded view of the marking device of Fig. 1;

Fig. 5 shows an embodiment where the marking roller may be retracted;

Fig. 6 is a schematic illustration of another example of the device according to the presently disclosed subject matter;

Fig. 7 is a schematic illustration of a method of making use of the device of the presently disclosed subject matter;

Fig. 8 is a schematic illustration of the method of replacing the marking agent; and

Fig. 9 is another schematic illustration of a method of making use of the device of the presently disclosed subject matter. DETAILED DESCRIPTION OF EMBODIMENTS

With reference to Figs. 1 to 4, there is illustrated a stud detector generally designated 10, comprising four principal elements, namely, a housing 20, a magnet 30 (Figs. 2A, 3A and 3B), a marking arrangement 40 (Fig. 3B), and a pulling cord 50.

The housing 20 comprises a bottom member 22 and a top member 24, made for example of a molded plastic material, attached one to another by four securing screws 12 (Figs. 2B, 3A and 3B). The bottom member 22 and the top member 24 are configured with inside faces 21 and 23, respectively, and outside faces 25 and 27, respectively (Fig. 3B), so that the outside face 25, constitutes a contact face of the housing, the contact face may be a continuous flat surface or a curved surface defining an imaginary flat surface. The housing 20 has an axis of symmetry Ai (Figs. 1 and 2), which, in the case that the housing is a substantially rectangular member, constitutes its central longitudinal axis.

The inside faces 21 and 23 are formed with vertically extending ribs 26 (Fig. 3 A) constituting a magnet seat configured for fixedly receiving therein the magnet 30, so that a magnet axis of symmetry A_∑ (Fig. 2A) is coaxial with the axis Ai of the housing 20, as shown in Fig. 2A.

The magnet 30 may be, for example, a Neodymium magnet or any other material making it suitable for use as far as size, shape, magnetic strength, price, etc. In a preferred embodiment, the magnet 30 is N35, provided by Magma Magnetic Technologies (www . magmamagnet s . co . il) having a maximum energy product of 33 - 36 MGOe (Mega Gauss Oersted), size (1 x lx ½)inch and nickel plated. Any magnet having a maximum energy product of at least 33 MGOe is suitable for the device of the present invention.

The housing 20 is sized and shaped so as to be held by a hand of a user and for the purpose of convenience may be formed with finger grips 15 (Figs. 1 and 2 A).

The housing 20 is further configured for receiving therein the marking arrangement 40. For this purpose the top member 24 of the housing 20 is formed with a passage 28 (Figs. 2A and 3A) and the bottom member 22 of the housing 20 is provided with axle recesses 49 (Fig. 4) within the inside face 21 thereof and an aperture 29 (Fig. 2B and 4), as will be further explained in detail. With reference to Figs. 3 A, 3B and 4, the marking arrangement 40 comprises a pad 42 soaked with marking agent (shown also in Fig.2A), fitted within a cartridge 41 and having a central axis A3, and a marking roller 44, having a central axis A4 (Fig 3B).

The cartridge 41 is a cap formed element, interior of which is provided with an pad axle 46 fitted between corresponding recesses 41' of the cartridge 41 (Figs. 3 A and 3B), configured for holding the pad 42 and allowing a rotation thereof about its axis A3. The cartridge 41, together with the pad 42, is configured to be extractably received within the passage 28 of the top member 24 of the housing 20 so that a cap surface 43 constitutes a part of the outside face 27 of the top member 24 of the housing 20, as clearly shown in Fig. 1. When received within the housing 20, the axle 46 and, consequently, the axis A₃ of the pad 42 are perpendicular to the axis Ai of the housing 20, as shown in Fig.2A.

The pad 42 is a disposable member and may be easily replaced when extracting the cartridge 41 from the housing 20, as shown in Figs. 8A through 8C. In Fig. 8A a lever 90 is inserted under the cap surface 43 and pushed in the direction represented by arrow 91, which causes the cartridge 41 to be lifted in the direction represented by arrow 92. In Fig. 8B the cartridge 41 is pulled vertically (arrow 93) out of the housing 20, whereby the pad 42 (not shown) may be replaced. In Fig. 8C the cartridge 41 with the new pad 42 is re- inserted into the housing 20 (arrow 94).

The marking agent may be any one of an ink, optionally disposable, a toner and a powdered material, configured for generating a visible mark on a surface.

The marking roller 44 (Fig.2B) is fitted within the housing 20 so that it is in contact with the pad 42 and possibly aligned therewith along a vertical axis V perpendicular to the axis Αχ. The marking roller 44 is held by a roller axle 48 (Figs. 3A, 3B and 4) fitted between the corresponding recesses 49 (Fig. 4) allowing the marking roller 44 to rotate about its axis A₄. The roller axle 48 is fitted perpendicularly to the axis Ai of the housing 20, as shown in Figs. 3 A and 4, so that the axis A₄ of the marking roller 44 is also perpendicular to the axis Ai and, consequently, to the axis A₃ of the pad 42, when the pad 42 is received within the housing 20.

The marking roller 44 partially extends through an aperture 29 so as to slightly project from the contact face 25 of the housing 20, as shown in Fig.2B, allowing it to contact a surface to which the detector 10 is applied when in use. The projecting portion of the marking roller 44 is perpendicular to the contact surface 25, in case the surface is flat. Otherwise, the marking roller is perpendicular to a virtual surface defined by the contact surface.

The marking roller 44 may be made of rubber or other flexible material and may be formed as a completely circular disc or may comprise several serrations 45 (Figs. 3B and 4) along its circumference, arranged so as to create a predetermined marking pattern as the marking roller 44 revolves when the detector 10 is displaced along the surface.

The pulling cord 50 is a flexible steel wire articulated to the housing 20 and extending therefrom through a cord passage 53. The pulling cord 50 has a first end 52 fixedly attached to a restraining element 54 (Figs. 3 A and 3B) within the housing 20 and a second end 56 provided with a gripping ring 58 (Figs. 3A and 3B). The restraining element 54 is located within the housing 20 on the axis Ai, as shown in Figs. 3A and 3B, so that the pulling cord 50 may be brought to a position when it is aligned with the axis Ai.

According to an embodiment of the present invention, the marking roller 44 may be inwardly retractable or may be provided with a cover, preventing it from contacting the surface when the marking is not desirable, e.g. before the magnet 30 has been aligned with the stud.

Fig. 5 shows an exemplary construction for enabling easy retraction and extraction of the marking roller 44. The pad 42 has been accommodated with a slot 51 around its circumference, the slot 51 deep enough to accommodate at least part of the marking roller 44. The recesses 49 of Fig. 4 have been replaced by open recesses 49', accommodating a longer roller axel 48', extending on both ends thereof beyond the edges of bottom member 22, and protruding through notches 59 which are formed in the top member 24. Pushing the roller axel 48' up (arrow 60) causes marking roller 44 to be partially inserted into slot 51, thus preventing it from protruding through aperture 29. Pushing the roller axel 48' back downwards releases marking roller 44 from slot 51 and returns it to the marking position.

Other arrangements for selectively operating the marking roller may be used. For example, a cover may be provided for easily covering and uncovering aperture 29 (not shown).

Alternatively, if marking is not desired before alignment of the magnet with the stud, the device may be held with its top member 24 sliding against the wall until the magnetic force is felt, thus preventing any marking from being performed.

With reference to Fig. 6, there is illustrated another example of a device according to the presently disclosed subject matter. The device 80 differs from the devices described above by its marking arrangement, which, in this case, is a marking tool 83 fixedly or detachably received within a housing 81 of the device 80. The marking tool 83 may comprise a marking agent 85, projecting from a bottom face 87 of the housing 81. In particular, the marking tool may be a pen, a pencil, graphite marker etc.

Referring now to Fig. 7, the stud detector 10 is configured for detecting a stud S located behind a wall surface W that cannot be visually detected by a user. The stud S is an elongated metal object having an expected orientation, which is a direction along which a central longitudinal axis A_s is expected to extend.

In particular, as can be appreciated from the description below, the stud detector 10 is configured for detecting the axis A_s of the stud S and marking a visible line L on the wall surface W, which represents the location of the stud axis As.

The method for detection of the axis A_s of the stud S is described hereinafter.

First, the user places the detector 10 over the wall surface W so the contact face 25 of the housing 20 contacts the wall surface W. The user then grips the device and freely displaces it flush over the wall surface W, until the detector 10 is magnetically attracted to the surface W, due to the magnetic force between the magnet 30 of the detector 10 and the stud S, i.e. the location of the stud S is approximately detected. This manual first stage renders the device 10 suitable for any surface, namely horizontal (ceiling) or vertical, since the device is held by the user until magnetic attraction holds the device to the surface. The strong magnetic force of magnet 30 renders the device 10 useful in an additional manner, namely for attracting metal screws, nails and the like to the top member 24 of the housing 20. This is especially useful when the work surface is a ceiling.

Next, while the detector 10 is magnetically attracted to the wall surface W, and the user applies a pulling force to the housing 20 by pulling the gripping ring 58 of the pulling cord 50 along a direction corresponding to the expected orientation of the stud S (as shown by an arrow B). A combination of the pulling force and the magnetic force applied to the detector 10 brings the detector 10 to a position where the axis Ai of its housing 20 is self-aligned with the axis A_s of the stud S.

Once the above alignment between the axis Ai of the detector and the axis As of the stud S is achieved, the user continues to pull the detector 10 while keeping the detector 10 in contact with the walls surface W and the pulling cord 50 is substantially aligned with the axis Ai. The pad 42 and the marking roller 44 rotate about their axes A3 and A4, respectively, perpendicularly to the expected orientation direction B, and the contact between them allows the marking roller 44 to transfer the marking agent from the pad 42 to the wall surface, thereby generating a visible mark thereon. The mark on the wall surface appears as a line L collinear with the axis As of the stud S.

Figs. 9A through 9C schematically illustrate the device 10 of the present invention in an exemplary operation of building a drywall. A drywall (110) is normally inserted into lower (100) and upper (not shown) tracks attached to the floor and ceiling respectively. The tracks are connected to one another with vertical metal beams 120. The drywall (110) is then screwed to the beams 120. The stud detector 10 of the present invention is configured to locate the beams 120 behind the drywall 110. In Fig. 9 A the user holds the device 10 in his hand, aided by the finger grips, and slides it along the wall in directions perpendicular (horizontal) to the expected direction of the beams (vertical), to locate a beam. In Fig. 9B, while the user still holds the device 10, a magnetic force attracts the device to the wall, namely a beam has been detected, and the user continues to move the device 10 along the expected orientation of the stud, while a line is being drawn by the marking arrangement. In Fig. 9C, once the user determines that the device 10 has been aligned with the stud, he continues work by pulling the gripping ring. In a preferred method of carrying out the present invention, the stage depicted in Fig. 9B may be eliminated, so that once the device 10 is attracted to the drywall 110, the user pulls the gripping ring in the expected orientation (vertical), thus causing the device 10 to align with the detected beam. The pulling is accompanied by a line being drawn along the beam center.

Those skilled in the art to which this invention pertains will readily appreciate that numerous changes, variations, and modifications can be made without department from the scope of the invention, mutatis mutandis.

Claims

1. A device for detecting an elongated metal object located behind a surface, the device comprising:

a housing having a substantially smooth contact face and an opposite face; a magnet fixedly received within the housing and configured for attracting the housing to the surface and staying in contact with said surface;

a marking arrangement received within the housing and at least partially projecting from said contact face and configured for generating a visible mark on said surface when the device is displaced along the surface; and

a pulling member articulated to the housing for displacing the device along an expected orientation of the metal object.

2. The device of claim 1, wherein the magnet has an axis of symmetry coaxial with an axis of symmetry of the housing.

3 The device of claim 1, wherein the magnet has a maximum energy product of at least 33 MGOe.

4. The device of claim 1, additionally comprising finger grips configured to facilitate the gripping of the device.

5. The device of claim 1, wherein said surface is a ceiling.

6. The device of claim 1, wherein said magnet is additionally configured for attracting metal objects to said opposite face of the housing.

7. The device of claim 6, wherein said metal objects comprise screws.

8. The device of claim 1, wherein the marking arrangement comprises a pad soaked with marking agent and a marking roller in contact with the pad when the marking arrangement is received within the housing, and configured for applying the marking agent on said surface, when in contact therewith.

9. The device of claim 8, wherein the marking roller is made of rubber.

10. The device of claim 8, wherein the marking roller is configured to rotate about an axis perpendicular to the direction of the expected orientation of the metal object.

11. The device of claim 8, wherein the pad is configured to be extracted from the housing.

12. The device of claim 8, wherein the pad is replaceable.

13. The device of claim 8, wherein the marking agent is any one of an ink, a toner and a powdered material.

14. The device of claim 1, wherein the pulling member is a cord having a first end fixedly attached to the housing, typically at a location on the axis of symmetry of the housing.

15. The device of claim 1, wherein the marking arrangement is configured to be retracted into the housing and extracted therefrom.

16. The device of claim 8, wherein the pad comprises a slot around its circumference, said slot configured to partly accommodate the marking roller and means for pushing the marking roller into said slot to prevent marking.

17. A method of detecting an elongated metal object located behind a surface, the method comprising:

providing a device comprising a housing having a substantially smooth contact face, a magnet fixedly received within the housing, a marking arrangement received within the housing and at least partially projecting from said contact face, and a pulling cord articulated to the housing;

manually holding the housing, bringing the contact face of the housing into contact with the surface and displacing the device thereover while keeping them in contact;

detecting a location in which the magnet attracts the housing to the surface; and applying a pulling force to the housing by the pulling the cord thereby causing the housing to displace along a direction corresponding to an expected orientation of the metal object, generating thereby a visible mark with the marking arrangement.

18. The method of claim 17, wherein the visible mark extends along a central axis of the metal object.

19. The method of claim 17, additionally comprising retracting the marking arrangement into the housing when marking is not desired and extracting the marking arrangement from the housing when marking is desired.