"Apparatus for drilling railway rails"

[0001] The present invention relates to a drill for drilling rails and track equipment in railway applications.

[ 0002 ] Apparatuses for drilling railway rails are known, comprising a motor mounted in axis with the drilling bit or drilling mill and which moves forward together with the bit itself during the operation of drilling. This structure involves a significant longitudinal dimension, which is often incompatible with certain points of the track, for example switches and the like, and generally does not allow the creation of non-horizontal holes.

[0003]A drill for drilling rails is known from Publication MI93A002026, having a body which supports an electrical motor or spark-ignition engine, a drilling tool, a reduction gear interposed between the motor and the drilling tool, as well as means for removably fastening the body with respect to an object to be drilled, in which means are provided for translating the drilling tool with respect to the body itself.

[0004]Drills for drilling rails of the known art still have certain drawbacks.

[0005]A first problem which has not been suitably resolved is the poor visibility of the drilling area, which is usually at least partially covered or obscured by the overall dimensions of the drill itself, of the fuel tank thereof and of the electrical supply cable thereof.

[0006]A second disadvantage relates to the electrical supply of electrical drills in remote areas without an electric network and, if a battery-operated drill is to be used, to the overall dimensions and weight of the required batteries which would obstruct the placement of the drill with respect to the rail and would compromise its mass distribution .

[0007]A third drawback is the poor versatility of known drills for rails for the creation of holes of different dimensions. When used with smaller mills to make smaller holes, a drill designed for a mill of large diameter would apply a too high torque and a too low speed, which would result in premature wear of the tools. Similarly, when used with larger mills to make larger holes, a drill designed for a mill of small diameter would apply a too low torque and a too high speed, which would cause the mill bit to work on the steel under abnormal and non-optimal conditions .

[0008]A fourth problem of the known art drills is the unpredictable occurrence of breakdowns, for example to the motor, due to the heavy conditions of use and often to the improper use of the drill.

[ 0009 ] Therefore , it is the object of the present invention to provide an apparatus for drilling railway rails having features such as to obviate at least some of the drawbacks of the known art.

[0010] These and other objects are achieved by means of an apparatus for drilling railway rails according to claim 1. The dependent claims relate to advantageous and preferred embodiments .

[ 0011 ] According to one aspect of the invention, an apparatus for drilling railway rails comprises:

- a battery operable electrical motor,

- a drilling tool defining a tool axis,

- a reduction gear interposed between the motor and the drilling tool,

- a rechargeable battery,

- a substantially "L"-shaped supporting portion having a first wing which forms a joining portion to which the electrical motor is coupled, and a second wing extended in a transversal direction with respect to the first wing and supporting the drilling tool,

in which the electrical motor is arranged on the second wing and is vertically separated therefrom,

wherein both the electrical motor and the second wing protrude from the first wing in a same drilling direction of the apparatus, giving the apparatus a "U" shape,

- means for removably fastening the supporting portion with respect to an object to be drilled,

- a lighting system having two light sources spaced from each other and arranged on two opposite sides with respect to a vertical working plane containing the tool axis, wherein the two light sources generate two light cones which at least partially overlap in a drilling area of the drilling tool.

[0012] The presence and the particular configuration of the lighting system improve the visibility of the drilling area and reduce the formation of shadows in said area.

[0013] In order to better understand the invention and appreciate the advantages thereof, certain non-limiting embodiments given by way of example are described below, with reference to the accompanying drawings, in which:

[0014] figure 1 is a perspective side view of a drilling apparatus according to the invention,

[0015] figure 2 is a partial sectional side view of the drilling apparatus in figure 1,

[0016] figure 3 is a front view of the drilling apparatus in figure 1,

[0017] figure 4 is a perspective top side view of the drilling apparatus in figure 1,

[0018] figure 5 is an enlarged view of a detail of the drilling apparatus in accordance with an embodiment,

[0019] figure 6 is a further enlarged view of a detail of the drilling apparatus in accordance with an embodiment.

[ 0020 ] Referring to the drawings, an apparatus 1 for drilling railway rails 2 comprises an electrical motor 3 which can be energized by a battery, a drilling tool 4 defining a tool axis 5, a reduction gear 6 interposed between the motor 3 and the drilling tool 4, a replaceable, rechargeable battery 7 and a supporting portion 8.

[0021] The supporting portion 8 may be substantially "L"- shaped with a first wing 9 forming a joining portion 10 to which the electrical motor 3 is coupled, and a second wing 11 extended in a transversal direction, e.g. approximately perpendicular, with respect to the first wing 9 and which supports the drilling tool 4. The electrical motor is arranged over the second wing 11 and is vertically separated therefrom, and both the electrical motor 3 and the second wing 11 protrude from the first wing 9 in a same drilling direction 12 of apparatus 1, giving the apparatus 1 a "U" shape.

[0022]As is known from MI93A002026, the "U" shape reduces the overall dimensions of the drilling apparatus 1, favorably balances the mass distribution thereof and allows it to be used in different positions.

[0023] The drilling apparatus 1 further comprises means 13 for removably fastening the apparatus 1, in particular the supporting portion 8, with respect to an object (rail 2) to be drilled.

[ 0024 ] According to an aspect of the invention, the drilling apparatus 1 comprises a lighting system 14 having two light sources 15, 16 spaced from each other and arranged on two opposite sides with respect to a theoretical vertical working plane 17 containing the tool axis 5. The two light sources 14, 15, preferably two LEDs or two LED groups, generate two light fields (cones) at least partially overlapping in a drilling area 18 of the drilling tool 4.

[0025] The presence and the particular configuration of the lighting system 14 improve the visibility of the drilling area 18 and reduce the formation of shadows in said area.

[0026] In one embodiment, the light sources 15, 16 are arranged at opposite ends of an elongated rod 19 connected to the electrical motor 3 and extended in a transversal direction, preferably orthogonal to the working plane 17. The light sources 15, 16 are advantageously arranged on a bottom side of the electrical motor 3 facing the second wing 11, but above the second wing 11 and vertically spaced from the tool axis 5. The light cones or fields of the light sources 15, 16 are directed forward (in the drilling direction 12) and downwards, as shown in figures 1 and 3. Furthermore, theoretical central axes of the light cones of the light sources 15, 16 are directed in a convergent manner towards the working plane 17, as shown in figure 3. This optimizes the lighting of the drilling area 18 and reduces the risk of blinding the user whose eyes are above and behind the light sources.

[ 0027 ] Advantageously, tthe light sources 15, 16 are arranged laterally outside the lateral overall dimension (orthogonal to the working plane 17) of the fastening means 13.

[0028] The references "above", "below", "upper", "lower", "upwards", "downwards", "vertical", "horizontal" in this description refer to the operative position of apparatus 1, as shown in figures 1, 2, 3.

[0029] The drilling apparatus 1 comprises an electronic control unit 21 connected to the rechargeable battery 7, the electrical motor 3, the lighting system 14, and to manual switching-on/command means, for example a button or a lever 22 and, when provided, further control, monitoring or signaling means, which will be described hereinbelow.

[0030] In one embodiment, the manual command means can be positioned in three separate switching positions: a stable off position, a stable on position and an instable rotational placement position of the drilling tool 4.

[0031] By bringing the manual command means to the stable on position, e.g. by pressing or moving button 22, said switching position is stably engaged even if the operator removes his/her finger from the command means, and the control unit 21 actuates the motor 3 and the motor remains on and running, preferably at the maximum- or working number of revolutions. The reduction gear 6 transfers the mechanical energy supplied by motor 3 to a mandrel which carries the drilling tool 4 and which performs the drilling of the rail 2.

[0032] The command means 22 may be manually brought to another switching position to stop the actuation of the electrical motor 3 at any time during the drilling operation.

[0033] By bringing the manual command means to the stable off position, e.g. by pressing or moving button 22, said switching position is stably engaged even if the operator removes his/her finger from the command means, and the control unit 21 turns off the motor 3 and the motor remains off and not running. The steps of turning off the apparatus 1 are dedicated to the placement of the apparatus 1 on the rail to be drilled, to the maintenance of the apparatus 1 or to the standby mode, for example.

[0034] The command means 22 may be manually brought to another switching position, e.g. to resume the operation of the electrical motor 3, at any time during the off step.

[0035] By bringing the manual command means to the instable placement position, e.g. by pressing or moving button 22, said switching position is not stably engaged and the control unit 21 actuates motor 3 at a minimum number of revolutions or at least at a reduced number of revolutions as compared to the maximum or working number of revolutions, and the motor carries out only one rotational step each time for each switching operation into the tool placement position, e.g. for every manual pressure on button 22. In the absence of switching to the tool placement position (in other words, of pressing the button), motor 3 remains off.

[0036] The reduction gear 6 transfers the mechanical energy supplied by motor 3 to the mandrel which carries the drilling tool 4 and which performs the placement step which allows an easy and precise rotational placement of the mandrel in a position which allows the access by a tightening tool (by means of dowel 39) and the release of the drilling tool 4. The single impulse imparted to the motor corresponds for example, to a 10°... 15° rotation of mandrel 36, which carries the drilling tool 4.

[0037] The command means 22 may be manually brought to another switching position to terminate the tool placement phase at any time during the tool placement phase.

[0038] The control unit (21) is configured so that, when the command means are switched to the on position:

[0039]- if a limit value of required torque (torque of motor 3) is exceeded, which is indicative of a deadlock situation (i.e. stop or significant slowing down), the motor 3 is turned off and it can be turned on again only once the command means have been switched to the off position and then switched back to the on position.

[ 0040 ] Thereby, the operator is "warned" about the deadlock situation, which is completely ineffective for the drilling and is damaging to motor 3, and may better adapt the drilling modes (advancing speed of tool 4, diameter of the mill of tool 4, adjustment of number of revolutions of motor 3) to the drilling conditions and specific features of apparatus 1.

[0041] The control unit 21 stores the total running time of the electrical motor 3 and, when provided, the number and technical parameters of the single drilling events, and generates a maintenance-need warning in dependency of the values stored and of the preset reference values, i.e. a maximum admissible running time.

[0042] In accordance with one embodiment, the drilling apparatus 1 comprises a multicolor display 23 in signal connection with the control unit 21 and having a first light-emitting area 24, e.g. green, at least a second light-emitting area 25, e.g. yellow, and at least a third light-emitting area 26, preferably red, e.g. by means of different colored LEDs.

[0043] The differently colored light-emitting areas may be sequentially arranged along a strip or in a sequence of circles or arcs, e.g. following the order: third light- emitting area 26-second light-emitting area 25-first light- emitting area 24-second light-emitting area 25-third light- emitting area 26. Alternatively, the differently colored light-emitting areas may be materially arranged in the same space, for example by means of multicolor LEDs.

[0044] The control unit 21 controls the multicolor display 23 so as to generate one or more of the following visual warnings :

[0045] Charge status of the battery 7, in which the lighting of the first light-emitting area 24 (green) indicates a high charge level, the lighting of the second light- emitting area 25 (yellow) indicates a sufficient charge level, the lighting of the third light-emitting area 26 (red) indicates an insufficient charge level. Lighting combinations are also contemplated, for example green- yellow or yellow-red, which indicate intermediate battery charge levels.

[ 0046 ] Anomaly during the drilling operation in which, when a preset maximum motor torque is exceeded, the multicolor display 23 indicates a deadlock situation by lighting the third light-emitting area (red) 26.

[ 0047 ] Electrical supply error in which, in case of insertion of a non-suitable battery and/or in case of insertion of battery 7 when the command means are switched to the on position, the multicolor display 23 indicates the anomaly by lighting the third light-emitting area (red) 26, e.g. in flashing mode.

[ 0048 ] Maintenance needed in which, when a preset maximum number of working hours is reached, the multicolor display 23 indicates that maintenance is needed, e.g. by flashing all the light-emitting areas 24, 25, 26 contemporaneously or in sequence.

[ 0049 ] Instantaneous drilling conditions in which the multicolor display 23 keeps the first light-emitting area (green) 24 on when motor 3 runs at its optimal conditions, and in which the multicolor display 23 progressively lights the second light-emitting area (yellow) 25 and then the third light-emitting area (red) 26 on a first side of the first light-emitting area (green) 24 in case of increasing motor torque over-request (deadlock situation) , and in which the multicolor display 23 progressively lights the second light-emitting area (yellow) 25 and then the third light-emitting area (red) 26 on a second side of the first light-emitting area (green) 24, opposite to the first side, if the required motor torque increasingly decreases below the optimal motor torque (situation of mill sliding on the steel with insufficient chip removal) .

[0050] In one embodiment, the multicolor display 23 is energized in the case of switching the command means to the on position and is turned off in the tool placement position and in the off position.

[0051] In one embodiment, the multicolor display 23 is also energized in the case of switching the command means to the tool placement position and in this case it remains on for a preset (and adjustable) time limit, e.g. 15 seconds, which is sufficient to provide the user with the warnings (maintenance, supply anomaly, etc.) described above.

[0052] In a further embodiment, the drilling apparatus 1 comprises a speed switch 27 with at least two or three stable switching positions, which allows the selection of the rotational speed of the motor 3 so as to be able to perform the drilling with mills of different diameters, while in any case remaining in an optimal circumferential speed range of the mill teeth.

[0053] In one embodiment, the control unit 21 is configured to light the lighting system 14 both in an on switching status and in a tool placement switching status.

[0054] In the on switching status, the two light sources (LEDs) 15, 16 are permanently on, i.e. over the entire drilling duration, as well as for a preset (possibly adjustable) control time, for example in the range of 10 sec ... 15 sec ... 20 sec, after the completion of the on switching phase. [0055] In the tool placement switching status, the two light sources (LEDs) 15, 16 are on for a preset (possibly adjustable) placement time, for example in the range of 15 sec ... 30 sec ... 45 sec, starting from the switching to the tool placement position.

[0056] In one embodiment, the lighting system 14 can be disabled and enabled again by means of a preset combination of controls and/or operations of handling the drilling apparatus 1, for example by keeping the command means pressed down in the tool placement position while battery 7 is engaged.

[0057] In contrast with a universal principle of electrical drills with a rechargeable battery according to which the battery is secured to the drill on a bottom side thereof and facing away from the drilling direction and drilling area, according to one aspect of the invention, the rechargeable battery 7 is reversibly mechanically coupled to a battery interface 28 of apparatus 1 formed in an upper portion of the electrical motor 3 facing in the drilling direction 12 (figures 1, 2) and preferably vertically above the tool axis 5 and substantially centered with respect to the working plane 17. Thereby, battery 7 forms the free end of the upper wing of the "U"-shape of the structure of apparatus 1, moves the barycenter of apparatus 1 closeer to rail 2, does not create shadows when lighting the drilling area 18, is not an obstacle for the user who is on the side opposite to the drilling area 18, and does not interfere with the ballast under rail 2.

[0058] The battery interface 28 and battery 7 are advantageously configured to be mechanically coupled and electrically connected to each other by translationally sliding battery 7 from top downwards or parallel to the extension of the first wing 9 of the supporting portion 8.

[ 0059 ] Battery 7 may be a 36V 4Ah rechargeable lithium ion battery.

[ 0060 ] Apparatus 1 may comprise adapter means for the mechanical coupling and the electrical connection of different rechargeable batteries.

[0061] In accordance with an embodiment, the drilling apparatus 1 comprises a further display 29 connected to the control unit 21 for displaying numerical operative parameters, numerical apparatus parameters, and numerical control parameters of the apparatus 1.

[0062] The supporting portion 8 is advantageously made of aluminum alloy.

[0063] The axis of the output shaft of the electrical motor 3 may advantageously be parallel to, but vertically spaced from, the tool axis 5 and therefore both the axes lie on the same working plane 17.

[0064] The reduction gear 6 interposed between the output shaft of the electrical motor 3 and the drilling tool 4 may comprise a set of gear wheels (which are preferably orthogonal to the axes of the motor shaft and of the tool 5 and) directly carried by the supporting portion 8 and received in the first wing 9 (figure 2) .

[0065]As is known and described in further detail in MI93A002026, means are provided for translating the drilling tool 4 with respect to the supporting portion 8, whereby during the advancing movement of the drilling tool 4 the supporting portion 8 and the motor 3 with battery 7 remain in a fixed position and the moved masses are very small .

[0066] The translation means may comprise an internally grooved sleeve 30 connected to a gear of the reduction gear 6 to be rotated by actuating the motor 3. Inside the grooved sleeve 30 there is arranged a hollow grooved shaft 31 which is rotationally coupled to sleeve 30 and which may slide with respect thereto. Shaft 31 is pivotally supported by a slider 32 which has a rack segment 33 with which the slider 32 meshes a gear 34 connected to an advancement lever 35.

[0067] The actuation of the advancement lever 35 results in the translation of slider 22 and of the grooved shaft 31 supported by the latter and rotated by the grooved sleeve 20. [0068] The grooved shaft 31 has a mandrel 36 for securing tool 4, the mandrel 36 being at an operative end of the grooved shaft 31 facing the drilling direction 12.

[ 0069 ] Finally, the fastening means 13 may be arranged at the free end of the second wing 11 of the supporting portion 8 and may comprise one or more jigs 37 which engage the leg of the rail 2 to be drilled, and a bridge lever system 38 which extends above the rail 2 and forms an abutment on the opposite side of the leg of the rail 2.

[0070] Those skilled in the art, in order to meet contingent and specific needs, can obviously make further changes and variants to the drilling apparatus according to the present invention, which are all contained within the scope of protection of the invention, which is defined by the following claims.