Claims:[0044] CLAIMS:
We claim:
1) A dualcontact electromagneticswitching apparatusfor starter, the apparatus comprising:
a) an outersleeve (115)rigidly fixed to a starter motor frame (401)wherein the starter motor is further mountedonto the engine;
b) a first core plate(106) fixedat the centre of the outersleeve inaxial direction;
c) a first electromagnetic coil (114)arranged ina first bobbin(111), wherein the first bobbin(111) isarranged inaxialdirection to the outer sleeve at one end;
d) a movable first plunger(116) arranged inan inner circumference of the firstelectromagnetic coil(114), wherein the first plunger(116)movesinaxial direction towards the first core plate(106);
e) a shift lever(402) connected to the first plunger(116)through anoperating rod(103), wherein one end of the shift lever(402)is connected to the operating rod(103) and other end is connected to the pinion;
f) a second electromagnetic coil(113) placed in a second bobbin, wherein the second bobbin isarranged inaxialdirection to the outer sleeve;
g) thesecond electromagnetic coil(113)arranged in between the first core plate(106) and a second core plate(112);
h) a second plunger(107) arranged inan inner circumference of thesecond electromagnetic coil(113), wherein the second plunger(107) moves in axial direction towards the secondcore plate(112);
i) a nonmagnetic material spindle(105)connected to one end of the second plunger(107);
j) a spindle(110)integrally connected to the second plunger(107), wherein the spindle carries a plurality of moving contact plates(108 a and 108 b), which are arranged at an offset distance;
k) a terminal base assembly (109) which carries a plurality of set of fixed contact terminals which arearranged rigidly to the outer sleeve in axial direction;
l) the first setof terminals comprising:
a. atleast one terminal, wherein one terminal(201)is connected to a battery andother terminal is interconnected to a third terminal(203), which is present in the second set of terminals; and
m) the second set of terminals comprising:
a. atleast one terminal, wherein one terminal(204) isconnected to starter motor andother terminal(203)is interconnected via a high resistance material(205).
2) The apparatus as claimed in claim 1, wherein said high resistance is added during cranking and after a predefined time the high resistance is removed, wherein the high resistance is added and removed using the second plunger.
3) The apparatus as claimed in claim 1, wherein said high resistance reduces inrush current during the cranking process.
, Description:[0001] DESCRIPTION OF THE INVENTION:
[0002] The following specification particularly describes the invention and the manner in which it is to be performed:
[0003] Technical field of the invention
[0004] The present invention relates toan electromagnetic switching apparatus for starter motor. More particularly, the present invention relates to an electromagnetic switching apparatus having a dual arrangement which adds and removes the high resistance to reduce inrush current during cranking.
[0005] Background of the invention
[0006] Generally to initiate an engine it must be rotated at some speed, so that the fuel and air is carried into the cylinders and compresses it. The shaft carries a pinion (gear wheel) which engages with a large ring gear around the rim of the engine flywheel and the engine is energized by connecting the starter terminal and battery terminal.The starter of the engine needs a huge amount of inrush current therewith a batteryis used to supply the electric current and it requires a large switch to withstand the high current. The switch has to be operated (ON/OFF) very quickly to avoid damageto the internal circuit of the engine.
[0007] Various types of conventional electromagnetic switching apparatus for starter motor are known in the prior art, wherein most of them use the devices in which huge amount of current is drawn during cranking,whichreduces the life of the starter motor and also occur interruption in electronic component in vehicle due to low voltage.
[0008] Hence, there is need of a switching apparatus for starter motor with a system having a simple structure that may be fitted with the existing solenoid and a technique to reduce inrush current during cranking process to increase the shelf life of the starter motor.

[0009] Summary of the invention
[0010] The present invention overcomes the drawbacks in the prior art and provides a dual contact electromagnetic switching apparatus for starter motor. In present invention,a high resistance is added during cranking and after a predefined time, the high resistance is removed, wherein thehigh resistance is added and removed using a second plunger. Therefore, the inrush current during the cranking process is reduced.
[0011] The present invention comprises an outersleeve which carries plurality of coils, wherein each coilcarries a plunger inaxialdirection.Afirst core plate is placed in between two electromagnetic coil and a spindle carrying two moving contact assembly is integrated into the secondplunger.The second core plate is fixed atthe rear end and a terminal base which carries fixed contact is placed at the end of the outer sleeve.
[0012] In one embodiment of the present invention, the dual contact electromagnetic switching apparatus for starter motorcomprisesan outersleeve rigidly fixed to a starter motor frame,wherein the starter motor is further mounted onto the engine. A first core plateis fixedat the centre of the outersleeve inaxial direction.A first electromagnetic coil is arranged ina first bobbin, wherein the first bobbin isarranged inaxialdirection to the outer sleeve at one end. Themovable first plunger is arranged inan inner circumference of the firstelectromagnetic coil, wherein the first plunger movesinaxial direction towards the first core plate.Ashift lever is connected to the first plungerthrough anoperating rod, wherein one end of the shift lever is connected to the operating rod and other end is connected to the pinion.A second electromagnetic coil is placed in a second bobbin, wherein the second bobbin isarranged inaxialdirection to the outer sleeve. Thesecond electromagnetic coilis arranged in between the first core plate and a second core plate anda second plungeris arranged inan inner circumference of thesecond electromagnetic coil, wherein the second plunger moves in axial direction towards the second core plate.
[0013] Further, thenonmagnetic material spindleis connected to one end of the second plunger, wherein the spindle carries a plurality of moving contact plates, which are arranged at an offset distance.
[0014] A terminal base which carries a plurality of setof fixed contact terminals arefixed rigidly to the outer sleeve in axial direction. The first setof terminals comprisesat least one terminal, wherein one terminalis connected to a battery andother terminal is interconnected to a third terminal which is present in the second set of terminals. The second set of terminals comprisesat least one terminal, wherein one terminal isconnected to starter motor andother terminal is interconnected via a high resistance.
[0015] According to preceding embodiments of the invention, the high resistance is added during cranking and after a predefined time the high resistance is removed, wherein the high resistance is added and removed using the second plunger,wherein said high resistance reduces inrush current during the cranking process.
[0016] The inventeddual contact electromagnetic switching apparatus for starter motor uses aninrush current reduction technique, wherein the high resistance is added during cranking and after a predefined time the high resistance is removed. Hence, the high resistance material reduces inrush current during the cranking process. In the present invention, since the inrush current is reduced, the lifeof the starter motor is increased.
[0017] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
[0018] Brief description of the drawings:
[0019] The foregoing and other features of embodiments will become more apparent from the following detailed description of embodiments when read in conjunction with the accompanying drawings. In the drawings, like reference numerals refer to like elements.
[0020] Figure 1 shows a cross sectional view of the dual contact electromagnetic switching apparatus for starter motor, according to one embodiment of the invention.
[0021] Figure 2 shows a perspective view of the terminal base assembly, according to one embodiment of the invention.
[0022] Figure 3 shows a circuit diagram of the dual contact electromagnetic switching apparatus for starter motor, according to one embodiment of the invention.
[0023] Figure 4 shows a cross sectional view of the arrangement of dual contact electromagnetic switching apparatus with starting motor, according to one embodiment of the invention.
[0024] Figure 5 shows a perspective view of the arrangement of dual contact electromagnetic switching apparatus with starting motor, according to one embodiment of the invention.
[0025] Figure 6 shows the front view of the arrangement of dual contact electromagnetic switching apparatus with starting motor, according to one embodiment of the invention.
[0026] Detailed description of the invention:
[0027] Reference will now be made in detail to the description of the present subject matter, one or more examples of which are shown in figures. Each embodiment is provided to explain the subject matter and not a limitation. These embodiments are described in sufficient detail to enable a person skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, physical, and other changes may be made within the scope of the embodiments. The following detailed description is, therefore, not be taken as limiting the scope of the invention, but instead the invention is to be defined by the appended claims.
[0028] The present invention provides a dual contact electromagnetic switching apparatus for starter motor. The present invention comprises an outersleeve which carries plurality of coils, wherein each coilcarries a plunger inaxialdirection.Acommon core plate is placed in between two electromagnetic coil and a spindle carrying two moving contact assembly is integrated into the secondplunger. The second core plate is fixed atthe rear end and a terminal base which carries two sets of fixed terminal with it, is placed at the end of the outer sleeve.
[0029] The present invention has a high resistance material which is added during cranking process and after a predefined time the high resistance is removed through a second plunger. Therefore, the dual arrangement to add and remove the high resistance is employed to reduce the inrush current during cranking.
[0030] Figure 1 shows a cross sectional view of the dual contact electromagnetic switching apparatus for starter motor, according to one embodiment of the invention. The dual contact electromagnetic switching apparatus for starter motor(100)comprisesan outersleeve(115)rigidly fixed to a starter motor frame(401),wherein the starter motor is further mounted onto the engine. A first core plate (106)is fixedat the centre of the outersleeve inaxial direction. A first electromagnetic coil (114) is arranged ina first bobbin(111), wherein the first bobbin(111)isarranged inaxialdirection to the outer sleeve at one end. The movable first plunger (116) is arranged inan inner circumference of the firstelectromagnetic coil(114), wherein the first plunger (116)movesinaxial direction towards the first core plate(106). A shift lever(402)is connected to the first plunger(116)through anoperating rod(103), wherein one end of the shift lever(402)is connected to the operating rod(103) and other end is connected to the pinion. A second electromagnetic coil(113) is placed in a second bobbin, wherein the second bobbin isarranged inaxialdirection to the outer sleeve. Thesecond electromagnetic coil(113)is arranged in between the first core plate (106)and a second core plate(112). A second plunger(107)is arranged inan inner circumference of thesecond electromagnetic coil(113), wherein the second plunger(107) moves in axial direction towards the second core plate (112).
[0031] Further, thenonmagnetic material spindle(105)is connected to one end of the second plunger (107)and the spindle(110) is integrally connected to the other end of the second plunger(107), wherein the spindle carries a plurality of moving contact plates(108 a and 108 b). The moving contact plates(108 a and 108 b)are arranged at an offset distance as shown in the FIGURE 1.A terminal base assembly (109)carries a plurality of setof fixed contact terminals, which are fixed rigidly to the outer sleeve in axial direction.
[0032] Figure 2 shows a perspective view of the terminal base assembly, according to one embodiment of the invention. The terminal base assembly (109)carries a plurality of setof fixed contact terminals, which are fixed rigidly to the outer sleeve in axial direction. The first setof terminals comprises atleast one terminal, wherein one terminal(201)is connected to a battery andother terminal(202) is interconnected to a third terminal(203) which is present in the second set of terminals. The second set of terminals comprises atleast one terminal, wherein one terminal(204)isconnected to starter motor andother terminal(203) is interconnected with the terminal of the first setof terminals. A high resistance material (205) is added in between the terminal (204) and the terminal (203).
[0033] The high resistance is added during cranking and after a predefined time the high resistance is removed, wherein the high resistance is added and removed using the second plunger,wherein said high resistance reduces inrush current during the cranking process.
[0034] Figure 3 shows a circuit diagram of the dual contact electromagnetic switching apparatus for starter motor, according to one embodiment of the invention.During cranking process, the high resistance is added and after a predefined time, the high resistance is removed. This is achieved by using a dual contact arrangement which adds high resistance to reduce the huge amount of inrush current during cranking processand removes the high resistance after a predefined time, whereinthe dual contact material used is copper.
[0035] Considering the terminals T1, T2, T3 and T4 in circuit diagram as shown in the FIGURE 3. The circuit is connected to the two setsof fixed contact terminals, wherein the first set has fixed terminals T1 and T3 and second set has fixed terminals T2 and T4 as shown in the FIGURE 3. In the first set of fixed terminals (T1 and T3), the terminal T1 is connected to the battery terminal.
[0036] In the second set of fixed terminals (T2 and T4), the terminal T4 is connected to the starter motor terminal. The terminal T2 and T4 are interconnected via resistance material (205) and the terminal T3 and T4 are short circuit through a copper wire.
[0037] In the present invention, when the restart signal is obtained from Engine Control Unit(ECU), the battery terminal connects the solenoid terminal S1. The first electromagnetic coil gets energized and first plunger(116)starts moving towardsthe first core plate(106).At the same time contact plate(108a)starts moving axially and closes the first set of fixed terminals (T1 and T3). Further the motor gets energized through the high resistance, wherein the high resistance reduces the inrush current and simultaneously pinion movement starts operating.
[0038] After a predefined time the second electromagnetic coil gets energized, wherein the predefined time is achieved by a delay circuit (D). Then,the second plunger starts movingin the axial direction and closes the second set of fixed terminal(T2 and T4). Hence the contact closure of second set of fixed terminal (T2 and T4) causes the resistor (205)to short/bypass.
[0039] Figure 4 shows a cross sectional view of the arrangement of dual contact electromagnetic switching apparatus with starting motor, according to one embodiment of the invention.The outer sleeve (115) of the dual contact electromagnetic switching apparatus(100) is firmly fixed to a starter motor frame (401), wherein the starter motor frame (401)is rigidly fixed to the engine.
[0040] Figure 5 shows a perspective view of the arrangement of dual contact electromagnetic switching apparatus with starting motor, according to one embodiment of the invention.
[0041] Figure 6 shows the front view of the arrangement of dual contact electromagnetic switching apparatus with starting motor, according to one embodiment of the invention.
[0042] The inventeddual contact electromagnetic switching apparatus for starter motor uses an inrush current reduction technique, wherein the high resistance is added during cranking and after a predefined time the high resistance is removed. Hence, the high resistance material reduces inrush current during the cranking process. In the present invention, since the inrush current is reduced, the shelf lifeof the starter motor is increased.
[0043] It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.