Field

[001 ] This application relates to solenoid assemblies. More specifically, the application provides a mechanism for amplifying the stroke of a solenoid armature.

Background

[002] Solenoid assemblies apply an electromagnetic signal to an armature to move the armature up or down. The distance that the armature travels is the stroke. To get a large distance stroke, it is necessary to use a longer solenoid assembly and to give up some of the force of the armature's motion, or it is necessary to use a larger supply of electromagnetic force. This increases the cost and size of the solenoid assembly.

SUMMARY

[003] The devices disclosed herein overcome the above disadvantages and improves the art by way of a solenoid assembly comprising a sliding arm with a stroke longer than the stroke of the armature

[004] A solenoid assembly comprises a pole piece. The pole piece comprises an inner chamber and inner grooves in the inner chamber, wherein the inner grooves are spaced to interface with a gear. The solenoid assembly comprises an

electromagnetic signal source surrounding the pole piece an armature configured to move in the inner chamber when an electromagnetic signal is transmitted by the electromagnetic signal source.

[005] A valve assembly comprises a flow path through a housing, at least one valve configured to selectively open and close the flow path, and a solenoid assembly. The solenoid assembly comprises a pole piece. The pole piece comprises an inner chamber and inner grooves in the inner chamber. The inner grooves are spaced to interface with a gear. The solenoid assembly further comprises an electromagnetic signal source surrounding the pole piece and an armature configured to move in the inner chamber when an electromagnetic signal is transmitted by the electromagnetic signal source. [006] A solenoid assembly comprises a pole piece. The pole piece comprises an inner chamber and an inner surface on the inner chamber. The inner surface contacts a roller. The solenoid assembly further comprises an electromagnetic signal source surrounding the pole piece and an armature configured to move in the inner chamber when an electromagnetic signal is transmitted by the electromagnetic signal source.

[007] A valve assembly comprises a flow path through a housing, at least one valve configured to selectively open and close the flow path, and a solenoid assembly. The solenoid assembly comprises a pole piece. The pole piece comprises an inner chamber and an inner surface on the inner chamber. The inner surface contacts a roller. The solenoid assembly further comprises an electromagnetic signal source surrounding the pole piece and an armature configured to move in the inner chamber when an electromagnetic signal is transmitted by the electromagnetic signal source.

[008] Additional objects and advantages will be set forth in part in the

description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosure. The objects and advantages will also be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

[009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the claimed invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[010] Figure 1 is cross-sectional of a pole piece assembly with an armature and a sliding arm.

[01 1 ] Figure 2A is a view of a solenoid assembly in a casing.

[012] Figure 2B is an exploded view of a solenoid assembly.

[013] Figure 3 is a cross-sectional view of an electromagnetic signal source around a pole piece, the pole piece having an inner chamber for movement of an armature therein. [014] Figure 4 is a cross-sectional view of a fuel valve assembly comprising a solenoid assembly.

[015] Figure 5 is a cross-sectional view of a pole piece assembly with balls instead of gears.

[016] Figure 6A is a cross-sectional view of a rotating member arrangement.

[017] Figures 6B-6C are cross-sectional views of rotating members.

DETAILED DESCRIPTION

[018] Reference will now be made in detail to the examples, which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Directional references such as "left" and "right" are for ease of reference to the figures.

[019] Figure 1 shows a cross-sectional view of a pole piece assembly 100 with an armature 102 and a sliding arm 103. The armature 102 is located in an inner chamber 141 of the pole piece 101 . The armature 102 can move along axis A toward and away from the back wall 146 of the inner chamber 141 .

[020] At least one gear 120 can be seated on the armature 102. The gear 120 has teeth 122 that interface with inner grooves 1 10 in the inner chamber 141 . A second gear 121 can also be seated on the armature 102. The second gear 121 can also have teeth 122 that interface with a second set of inner groves 1 1 1 in the inner chamber 141 .

[021 ] The gears 120, 121 are seated on the armature 102 in such a way that they do not move along axis A on the armature 102. The gears 120, 121 , however, can rotate, thereby allowing armature 102 to move toward and away from back wall 146. The gears 120, 121 can include a bearing that rotates around a shaft or dowel 123.

[022] The armature 102 can be a single unit or it can include a first portion 144 connected to a second portion 145. The first portion 144 can be a dowel, pin, or shaft press-fit or snap fit into the second portion 145. An end 150 of the first portion 144 can extend into a hollow portion 142 of the pole piece 101 . The first portion 144 can be slip- fit into a passageway 151 connecting the hollow portion 142 to the inner chamber 141. This arrangement allows the armature 102 to move axially within the pole piece 101 while reducing movement or vibrations in directions away from axis A. This arrangement helps to keep the pole piece 101 aligned along axis A with the armature 102 and the sliding arm 103.

[023] The sliding arm 103 is located in a hollow portion 140 in the armature 102. The sliding arm 103 can move along axis A towards and away from the back wall 143 of the hollow portion 140. The sliding arm 103 has grooves 130 spaced apart to interface with the teeth 122 of the gear 120 seated on the armature 102. The sliding arm can have multiple sets of grooves 130, 131 configured to interface with both gears 120, 121 .

[024] When the sliding arm 103 moves, the gears 120, 121 rotate. Likewise, when the armature 102 moves, the gears 120, 121 rotate. For example, when the armature 102 moves away from back wall 146, gear 122 rotates in a clockwise direction and gear 121 rotates in a counterclockwise direction. This rotation pushes the sliding arm away from back wall 143 of the armature 102. Thus, the sliding arm moves along axis A at a faster rate than the armature 102. For example, if sliding arm is moving along axis A at a rate R _s relative to the armature 102 while the armature 102 is also moving along axis A at a rate R _a relative to the pole piece 101 , which is not moving along axis A, then the sliding arm 103 is moving at a rate of R _s + R _a along axis A relative to the stationary pole piece 101 .

[025] The spacing of gear teeth 122, the spacing of inner groves 1 10, 1 1 1 , and the spacing of grooves 130, 131 can be set to determine the axial movement, or stroke, of the armature 102 and sliding arm 101 .

[026] The depth of the hollow portion 142 and the inner chamber 141 can be selected to meet the needs of the solenoid assembly 100. For example, these areas can be made deeper to allow the armature 102 more room to move a greater distance along axis A. Likewise, hollow portion 140 can be made deeper to allow the sliding arm 103 to move a greater distance along axis A. This axial movement can be called a stroke. Thus, length of the stroke of the sliding arm 103 is longer than the stroke of the armature 102. Also, less magnetic force needs to be applied to move the sliding arm 103 and armature 102.

[027] Figure 2A is a view of an assembled solenoid assembly 200. Figure 2A includes an upper flux collector 201 , a casing 202, an electrical input port 209, a lower flux collector 208, and a pole piece 207. An exploded view of the solenoid assembly 200 is shown in Figure 2B. The solenoid assembly includes an upper flux collector 201 , casing 202, magnet wire 203, terminal 204, bobbin 205, diode 206, pole piece 207, and lower flux collector 208.

[028] Figure 3 is a cross-sectional view of a solenoid assembly 300. Solenoid assembly 300 includes a pole piece 301 surrounded by magnetic wire 313. An armature

302 is located in the pole piece 301 and a sliding arm 303 is located in the armature 302. The pole piece 301 , armature 302, and sliding arm 303 are aligned along axis A.

[029] Figure 3 shows a solenoid assembly 300 with the sliding arm 303 in a lifted position. The original position of the top 348 of the sliding arm is marked as P2. This is the position where the sliding arm 303 is completely lifted, marking its upper boundary along axis A. Position P6 marks the position of the top 348 of the sliding arm

303 in an extended position. The sliding arm 303 reaches the extended position after the sliding arm 303 moves away from back wall 342 of the armature 302. D2 is the distance between P2 and P6, or in other words, D2 is equal to the distance that the sliding arm 303 traveled from its original position P2 to an extended position P6. D2 can be called the distance of the stroke of the sliding arm 303 in the extended position.

[030] D2 is greater than D. D is the distance that the armature 302 traveled from the original position P1 of the top 347 of the armature 302 to an extended position P5 of the top 347 of the armature 302. Thus, the stroke of the sliding arm 303 is longer than the stroke of the armature 302 at the extended position.

[031 ] The relationship between the stroke distance of the sliding arm 303 to the stroke distance of the armature 302 at the extended position can be calculated using equation (1 ), where

D2 = D ^* N eq. (1 )

D2 = distance of the stroke of the sliding arm at the extended position

D = distance of the stroke of the armature at the extended position

N = a factor which equals a number greater than 1

[032] The magnitude of N can depend on many factors, including the shape and and size of the rollers and gears attached to the armature. Figure 6A shows a gear 620 having a first side 696 with a distance of n from the center C of the gear 620 to the first pitch surface 693 and a second side 697 with a distance of r ₂ from the center C of the gear 620 to the second pitch surface 694. Because n is greater than r ₂ , the rotational speed of gear 620 at the first pitch surface 693 is greater than the rotational speed at the second pitch surface 694. When teeth 622a mesh with grooves 630 on sliding arm 603 and teeth 622b mesh with grooves 610 on pole piece 601 as shown in Figure 6A, the sliding arm 603 moves faster than the armature 602. This means the sliding arm 603 also has a longer stroke than the armature 602. One can increase or decrease both the speed and stroke of the sliding arm 603 by changing the sizes and shapes of rotating gear 620, pole piece 601 , armature 602, and sliding arm 603.

[033] When the rollers or gears are uniform in size and shape, N equals 2.

Figure 5 shows such an arrangement. Thus, the sliding arm 503 moves twice as fast as the armature 502. And the sliding arm 503 can have a stroke twice as long as the stroke of armature 502.

[034] Both rollers and gears are rotating members that can be used to amplify the stroke of a sliding arm. Figure 6B shows an example of a toothed gear 620 with first teeth 622a on first side 696 and second teeth 622b on second side 697. The rotating member need not be a roller or toothed gear. For example, as shown in Figure 6C, rotating member 620C can amplify the stroke of a sliding arm. Instead of having teeth, rotating member 620C has a textured surface, for example, with bumps 624a and bumps 624b. Rotating member 620C need not have a textured surface. Frictional forces can be sufficient when sides 696, 697 are smooth.

[035] Rotating member 620C can contact the outer surface of a sliding arm in a similar way as rotating gear 620 contacts the sliding arm 603 in Figure 6A except that rotating member 620C does not have teeth that engage with grooves in the sliding arm. Rotating member 620C can also contact the outer surface of a pole piece like the rotating gear 620 of Figure 6A contacts pole piece 601 except that rotating member 620C does not have teeth that engage with grooves in the pole piece.

[036] Rotating member 620C has a first side 696 with a distance di away from the center C of rotating member 620C and a second side 697 with a distance of d ₂ away from the center C of rotating member 620C. Because di is greater than d ₂ , rotating member 620C amplifies the stroke of a sliding arm. One can adjust di and d ₂ to achieve the desired amplification. [037] The amplified stroke is advantageous in many applications. One example application is fuel valve actuation, where a solenoid assists with fluid pressure control. Figure 4 shows a valve assembly 400 with a solenoid assembly 460 in the extended position, where the armature 302 has moved a distance of D from its original position P1 and the sliding arm 403 has traveled a distance of D2 from its original position P2. Figure 3 shows the sliding arm 303 and the armature 302 in a lifted position, where both the sliding arm 303 and the armature 302 have moved away from the extended position towards back wall 341 of the inner chamber 341 .

[038] The distance between the original position P1 of the armature 302 and the lifted position P3 of the armature 302 is D4. The distance between the original position P2 of the sliding arm 303 and the lifted position P4 of the sliding arm 303 is D3. In Figure 3, D3 is less than D4. This means that the distance between the top 348 of the sliding arm 303 and its original position P2 is less than the distance between the top 347 of the armature 302 and its original position P1 . Even though the sliding arm 303, when in the extended position, has a longer stroke than the armature 302, the sliding arm 303 can move closer to its original position P2 than the armature 302 can move to its original position P1 when in the lifted position. This is possible because the sliding arm 303 moves at a faster rate than does the armature 302. Gears 120, 121 allow the sliding arm 303 to move at a faster rate. When the sliding arm 303 is moving downward to the extended position, gears 120, 121 push the sliding arm 303 downward away from the armature 302, thereby causing the sliding arm 303 to move downward faster than the armature 302. When the sliding arm 303 is moving upward to the lifted position, gears 120, 121 pull the sliding arm 303 upward toward the armature 302, thereby causing the sliding arm 303 to move upward faster than the armature 302.

[039] Figure 4 shows a cross-sectional of a valve assembly 400 with a solenoid assembly 460. The valve assembly 400 has a first flow path 471 in the housing 490 of the valve assembly 400 that can be connected to second flow path 472. Together, first flow path 471 and second flow path 472 can be a single flow path when connected. Fluid can flow from first flow path 471 to second flow path 472 or from second flow path 472 to first flow path 471 . A check valve 480 or other valve can be connected to either first flow path 471 or second flow path 472. Check valve 480, as shown in Figure 4, can serve to regulate fluid pressure, for example, opening when the pressure in flow path 471 reaches a certain threshold, thereby allowing fluid to flow from first flow path 471 to second flow path 472.

[040] Valve 404 can allow or prevent a fluid from flowing between first flow path 471 and second flow path 472. Valve 404 can be a poppet valve surrounded by an outer valve 405. When in the lifted position, valve 404 allows fluid to flow either from flow path 471 to flow path 472 or from flow path 472 to flow path 417. The flow can occur even when outer valve 405 is closed when valve 404 is in the lifted position.

Figure 4 shows an arrangement where both valve 404 and outer valve 405 are closed. Pressure in second flow path 472 can build to a point where it raises outer valve 405, allowing fluid to flow from second flow path 472 to first flow path 471 . To raise outer valve 405, the pressure in flow path 472 must overcome the force exerted by spring 406, which biases outer valve 405 toward the closed position.

[041 ] The sliding arm 403 can be linked to valve 404. Thus, valve 404 moves along axis A as the sliding arm 403 moves along axis A. When the sliding arm 403 is in the extended position, valve 404 is closed, as show in Figure 4. When the sliding arm is in the lifted position, valve 404 is open, thereby allowing fluid to flow from first flow path 471 to second flow path 472.

[042] Valve 404 is lifted when an electric signal or current runs through the magnetic wire 413. The magnetic wire 413 is an electromagnetic signal source. An electricity source, for example, an alternator, battery, generator, or other electric current source 493 can provide the electrical current. The current can be controlled by a control system 492, for example, a computer or microcomputer. When electric current flows through the magnetic wire 413, the magnetic wire 413 transmits an electromagnetic signal and a magnetic field is created. This creates a magnetic force, which can attract metallic or other ferromagnetic materials.

[043] The armature 402 can comprise metallic or ferromagnetic materials. For example, first portion 445 can be made of metal. The electromagnetic signal created by current passing through the magnetic wire attracts the first portion 445 of the armature 402. The magnetic force of the electromagnetic signal can pull first portion 445 upward toward back wall 449 of the hollow portion 442 of the pole piece 401 . The magnetic force can also push first portion 445 downward away from back wall 449, for example, when first portion 445 is made of a permanent magnet. When the first portion 445 or any portion of the armature 402 is made of metallic or ferromagnetic material, the sliding arm can be made of a nonmetallic or nonferromagnetic material. Thus, sliding arm 403 need not be affected by the magnetic force. The sliding arm 403 and the second portion 444 of the armature can be made of a plastic or other lightweight moldable material.

[044] The amount of magnetic force depends on the amount of current flowing through the magnetic wire 413. The magnetic force also depends on the number of coils of wire. The force can enter the solenoid assembly 460 through terminal 491 . Terminal 491 can be connected to an electric current source 493 and a control system 492, for example, a microcomputer or other control system 492. The control system 492 can be programmed to send a selected amount of electrical current at a selected time, thereby controlling when valve 404 is opened or closed.

[045] A spring can bias valve 404 to remain in the closed position until valve 404 is lifted by the solenoid assembly. Gravity and fluid pressure can also bias valve 404 to remain in the closed position. The magnetic force, therefore, must be large enough to overcome the force exerted by any biasing force.

[046] Figure 5 shows a cross-sectional of a pole piece assembly 500 comprising rollers 520 instead of gears. The pole piece assembly 500 of Figure 5 can amplify the stroke of sliding arm 503. Like the gears 120, 121 of Figure 1 , rollers 520 can rotate thereby pushing sliding arm 503 downward when armature 502 moves downward. And rollers 520 can rotate pushing sliding arm 503 upward when armature 502 moves upward. The outer surface 540 of rollers 520 engages the outer surface 530 of sliding arm 503. The engagement is maintained by frictional forces, thereby preventing rollers 520 and sliding arm 503 from slipping relative to each other. The outer surface 540 of rollers 520 engages the surface 550 of inner chamber 541 .

[047] Rollers 520, sliding arm 503, and pole piece 501 can be made of an anti- slip material to increase the friction forces where rollers 520 contact sliding arm 503 and where rollers 520 contact the inner chamber 541 of pole piece 501 . Rollers 520, sliding arm 503, and pole piece 501 can also be coated with an anti-slip material to increase the friction forces. Rollers 520 can be balls, cylinders, or other shapes. Rotating members, for example, the rotating member shown in Figure 6C, can be made of anti- slip material or coated with anti-slip material. Texture, for example bumps, knurls, or ridges, can be added to the surfaces of the rollers, gears, rotating members, sliding arm, and pole piece to increase the frictional forces, thereby preventing slip. These parts can comprise the same anti-slip material or comprise different anti-slip materials.

[048] Other implementations will be apparent to those skilled in the art from consideration of the specification and practice of the examples disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope of the invention being indicated by the following claims.