A power-on detection device for electric energy meter circuit board

Abstract

The present invention relates to the field of circuit board detection, and discloses a power-on detection device for an electric energy meter circuit board, comprising a machine platform and a test module arranged on the machine platform for circuit board detection, wherein a support assembly for supporting the circuit board is arranged on the machine platform, and adjustment assemblies are arranged on the top of the machine platform and on both sides of the support assembly, and a control assembly for driving the adjustment assembly is arranged on the top of the machine platform; the two adjustment assemblies can be driven to approach the circuit board through the control assembly, and when the two adjustment assemblies are attached to the circuit board, the circuit board can be lifted up in a horizontal state through the control assembly and the adjustment assembly. The present invention can lift the circuit board to a horizontal state for detection through the cooperation between the machine platform, the support assembly, the adjustment assembly, the control assembly, etc., to avoid the circuit board tilting on the machine platform to affect the contact of the test module, and can effectively ensure the overall detection effect.

Description

Technical Field

[0001] The invention relates to the technical field of circuit board detection, and in particular to a power-on detection device for an electric energy meter circuit board. Background Art

[0002] Circuit boards are composed of multiple integrated circuit chips and other components to achieve various electronic functions. Pin continuity testing is a necessary step before using chips and components. Its purpose is to detect whether the electrical connectivity between pins is good, and then determine whether the chip or component is normal.

[0003] For example, the patent document with Chinese patent announcement number CN221883823U discloses a circuit board pin detection device, comprising: a control box, in which a detection circuit is arranged, and the detection circuit includes a detection switch; a workbench, which is arranged on the control box and is provided with perforations, the number of perforations is the same as the number of pins of the power module to be detected, and the positions of the perforations are the same as the relative positions of the pins of the power module, the pins of the power module can be inserted into the corresponding perforations at the same time, and the detection switch is located directly below the perforations; a pressure block, which is arranged on the control box and located directly above the workbench, can move up and down, and when it moves to the lowest position, the pin can push the corresponding detection switch to open it.

[0004] After the circuit boards of this application and most of the prior art are placed in the positioning grooves, the circuit boards are usually in a tilted state. When the probes of the subsequent test modules descend and contact the pins, the circuit boards may further tilt, making it impossible to ensure effective contact between the test modules and the pins, and further unable to ensure the overall detection effect. There are certain limitations in use.

[0005] Therefore, it is necessary to provide a power-on detection device for an electric energy meter circuit board to solve the above technical problems. Summary of the invention

[0006] The object of the present invention is to provide a power-on detection device for an electric energy meter circuit board to solve the problems raised in the above background technology.

[0007] In order to achieve the above purpose, a power-on detection device for an electric energy meter circuit board is designed, which can lift the circuit board to a horizontal state and ensure effective contact of a test module.

[0008] Based on the above ideas, the present invention provides the following technical solutions: a power-on detection device for an electric energy meter circuit board, comprising a machine platform and a test module arranged on the machine platform for circuit board detection, wherein the machine platform is provided with a support assembly for supporting the circuit board, and adjustment assemblies are arranged on the top of the machine platform and on both sides of the support assembly, and a control assembly for driving the adjustment assembly is arranged on the top of the machine platform; the two adjustment assemblies can be driven to approach the circuit board through the control assembly, and when the two adjustment assemblies are attached to the circuit board, the circuit board can be lifted up in a horizontal state through the control assembly and the adjustment assembly.

[0009] As a further solution of the present invention: the support assembly includes a plurality of base plates that slide with the machine table, the plurality of base plates are arranged in a one-to-one corresponding manner, a first spring is fixedly installed between the base plates and the machine table, a groove is provided on the top of the machine table for the base plates and the first spring to be placed, and the first spring makes the top surface of the base plates flush with the top surface of the machine table.

[0010] As a further solution of the present invention: the adjustment component includes a slider driven by the control component and designed in an inverted U shape, a support rod is rotatably installed at the bottom of the slider, a push plate and a gear are fixedly installed on the outer surface of the support rod, and a rack is slidably installed at the bottom of the slider that meshes with the gear and is fixedly connected to the control component.

[0011] As a further solution of the present invention: when the rack moves and drives the gear to rotate, the gear can drive the push plate to rotate 180 degrees through the support rod, and the push plate is in a horizontal state before and after the rotation.

[0012] As a further solution of the present invention: the rack is designed in two sections, one section is made of hard material and is fixedly connected to the control component, and the other section is made of elastic material and is connected to the gear transmission; the interior of the slider is provided with a slot for the rack to slide and is designed in an L-shape as a whole.

[0013] As a further solution of the present invention: the control component includes a cylinder fixedly connected to the machine platform, the output shaft of the cylinder is fixedly installed with a partition fixedly connected to the rack, and the end of the partition away from the cylinder is provided with a transmission member for driving the slider.

[0014] As a further solution of the present invention: the transmission member includes a cross bar fixedly connected to the partition, the slider is movably sleeved on the outer surface of the cross bar, and the outer surface of the cross bar is sleeved with a second spring that resists the slider.

[0015] As a further solution of the present invention: the transmission member includes an inclined rod, the slider includes an upper seat slidably matched with the inclined rod and a lower seat slidably matched with the upper seat, and the support rod, base, push plate, gear, slot and rack are all placed on the lower seat.

[0016] As a further solution of the present invention: a counterweight block that fits the rack is slidably installed inside the slot, the counterweight block abuts against the end of the rack away from the partition and is located above the rack. When the rack moves, the counterweight block can be pushed to move up and down along the slot.

[0017] As a further solution of the present invention: the inclined rod is designed to be inclined downward, and when the upper seat moves along the inclined rod, the lower seat can slide up and down based on the upper seat, and a plurality of balls are movably embedded in the bottom of the lower seat.

[0018] Compared with the prior art, the beneficial effects of the present invention are: through the cooperation between the machine, the support component, the adjustment component and the control component, the circuit board can be lifted to a horizontal state for detection, so as to avoid the circuit board tilting on the machine to affect the contact of the test module, and effectively ensure the overall detection effect. At the same time, the two adjustment components also have the effect of automatically centering the circuit board when they are relatively close, which can further ensure the detection effect of the circuit board and have higher practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0020] Figure 1 It is a three-dimensional diagram of the overall structure of the present invention;

[0021] Figure 2 It is a schematic diagram of the machine platform and bottom plate structure of the present invention;

[0022] Figure 3 It is a schematic diagram of the bottom plate and the first spring structure of the present invention;

[0023] Figure 4 It is a schematic diagram of the structure of the cross bar and the second spring of the present invention;

[0024] Figure 5 It is a schematic diagram of the structure of the slider and the push plate of the present invention;

[0025] Figure 6 for Figure 5 A magnified view of the structure at center;

[0026] Figure 7 It is a schematic diagram of the upper seat and the lower seat structure of the present invention;

[0027] Figure 8 It is a schematic diagram of the structure of the card slot and the counterweight block of the present invention;

[0028] Fig. 9 It is a schematic diagram of the sleeve and inner rod structure of the present invention;

[0029] Fig.10 It is a schematic diagram of the inner rod and through hole structure of the present invention.

[0030] In the figure: 1, machine; 2, test module; 3, support assembly; 4, adjustment assembly; 5, control assembly; 301, bottom plate; 302, first spring; 303, groove; 401, slider; 402, through hole; 403, support rod; 404, push plate; 405, rack; 406, gear; 407, base; 408, slot; 409, counterweight; 4011, upper seat; 4012, lower seat; 501, cylinder; 502, partition; 503, cross bar; 504, second spring; 505, inclined rod; 5051, sleeve; 5012, inner rod. DETAILED DESCRIPTION

[0031] Embodiment 1:

[0032] See also Figures 1 to 6 The embodiment of the present invention provides a power-on detection device for an electric energy meter circuit board, which is mainly used to make the circuit board correspond to the test module 2 in a horizontal state and complete the detection. The device includes a machine platform 1 and a test module 2 for pin detection arranged on the machine platform 1. A support component 3 for supporting the circuit board is arranged on the machine platform 1. Adjustment components 4 are arranged on the top of the machine platform 1 and on both sides of the support component 3. A control component 5 for driving the adjustment component 4 is arranged on the top of the machine platform 1.

[0033] In this embodiment, the two adjustment components 4 are respectively located on the front and rear sides of the support component 3, and the circuit board is taken and placed from the left and right directions; in actual applications, the two adjustment components 4 can also be located on the left and right sides of the support component 3, and the circuit board is taken and placed from the front and rear directions.

[0034] After the circuit board is placed on the supporting assembly 3, the two adjusting assemblies 4 are driven to approach the circuit board through the controlling assembly 5. After the two adjusting assemblies 4 are in contact with the circuit board, the controlling assembly 5 and the adjusting assembly 4 can lift the circuit board in a horizontal state for the testing module 2 to detect.

[0035] Among them, the test module 2 can move in the XYZ direction, and the XYZ direction is the existing rectangular coordinate system. The test module 2 can use the existing probe detection pin method. The form of the probe can be like the probe of the electric energy meter. The detection is completed by contacting the pin. It is an existing mature technology and will not be described in detail here.

[0036] Reference Figure 2 and Figure 3 In this embodiment, preferably, the supporting assembly 3 includes a plurality of bottom plates 301 slidably matched with the machine platform 1, the plurality of bottom plates 301 are arranged in a one-to-one corresponding manner along the machine platform 1, and a first spring 302 is fixedly installed between the bottom of the bottom plate 301 and the machine platform 1, and the first spring 302 enables the top surface of the bottom plate 301 to be flush with the top surface of the machine platform 1.

[0037] Furthermore, a groove 303 is provided on the top of the machine 1 for accommodating a plurality of bottom plates 301 and first springs 302 ; when the bottom plates 301 are forced to move into the grooves 303 , the first springs 302 can be used to lift and reset the bottom plates 301 .

[0038] Reference Figures 3 to 6 In this embodiment, preferably, the adjustment component 4 includes a slider 401 driven by the control component 5, and the slider 401 is designed in an inverted U shape. A support rod 403 is rotatably mounted at the bottom of the slider 401, and a push plate 404 and a gear 406 are fixedly mounted on the outer surface of the support rod 403. A rack 405 meshing with the gear 406 and fixedly connected to the control component 5 is also slidably mounted at the bottom of the slider 401. The gear 406 is driven to rotate by the movement of the rack 405, and the gear 406 can drive the push plate 404 to rotate 180 degrees through the support rod 403; it can be understood that the teeth on the rack 405 are incomplete, as long as they can drive 180 degrees.

[0039] Further, see Figure 5 The bottom of the slider 401 is fixedly installed with a base 407 for the support rod 403 to rotate and assemble. The support rod 403 can rotate back and forth 180 degrees based on the base 407. In the initial state, the support rod 403 drives the push plate 404 to be flush with the inner wall of the slider 401. When the support rod 403 rotates 180 degrees, the push plate 404 can rotate out of the slider 401; at the same time, the push plate 404 is in a horizontal state before and after the rotation. During the 180-degree rotation process, the push plate 404 can squeeze the bottom plate 301 to move it into the groove 303 and compress the first spring 302.

[0040] In order to prevent the rack 405 from falling onto the top of the circuit board after moving and affecting the processing, the rack 405 can be designed in two sections, one of which is made of hard material and fixedly connected to the control component 5, and the other is made of elastic material and can be deformed. It can be understood that the section of elastic material is the section with teeth, which is used for transmission connection with the gear 406. Further, a slot 408 for the rack 405 to slide is provided inside the slider 401, and the slot 408 is designed in an L-shape as a whole, so that the rack 405 can turn to an upward trend after passing the gear 406, instead of moving horizontally to the top of the circuit board.

[0041] Reference Figures 3 to 6In this embodiment, preferably: the control component 5 includes a cylinder 501 fixedly connected to the machine 1, and the output shaft of the cylinder 501 is fixedly installed with a partition 502 fixedly connected to the hard section of the rack 405, and the end of the partition 502 away from the cylinder 501 is provided with a transmission member for driving the slider 401. When the cylinder 501 is started to drive the partition 502 to move, the partition 502 can drive the slider 401 to move synchronously through the transmission member. When the slider 401 is attached to the circuit board, the slider 401 can be relatively close to the partition 502 through the transmission member, so that the rack 405 moves along the slot 408 to drive the gear 406 to rotate.

[0042] In this embodiment, the transmission member includes a horizontally designed cross bar 503 fixedly connected to the partition 502, and the slider 401 is movably sleeved on the outer surface of the cross bar 503, and the outer surface of the cross bar 503 is sleeved with a second spring 504 that abuts against the slider 401, and the second spring 504 can be respectively fixedly connected to the partition 502 and the slider 401. When the partition 502 moves, the slider 401 can be driven to move synchronously through the cross bar 503 and the second spring 504, and when the slider 401 contacts the circuit board, it moves toward the partition 502 along the cross bar 503.

[0043] Furthermore, a through hole 402 is opened on the surface of the slider 401 along the front-to-back direction, and the through hole 402 is for the cross bar 503 to pass through. The through hole 402 is designed to be through-type based on the slider 401. Since the through hole 402 corresponds to the cross bar 503, it can be known that the through hole 402 is also in a horizontal state.

[0044] When in use, the circuit board is placed on several bottom plates 301 and the cylinder 501 is started to drive the partition 502 to move toward the bottom plate 301. At this time, the partitions 502 on both sides can drive the two sliders 401 to move synchronously through the crossbar 503 and the second spring 504 until the sliders 401 fit the circuit board. After fitting, the partition 502 moves again, which will make the slider 401 relatively close to the partition 502 along the crossbar 503 and squeeze the second spring 504. The slider 401 will move the rack 405 during the approaching process, and then drive the push plate 404 to rotate 180 degrees through the gear 406 and the support rod 403; when the push plate 404 rotates, it can squeeze the bottom plate 301 to move it into the groove 303 and compress the first spring 302. After the push plate 404 rotates, it can contact the bottom surface of the circuit board. At this time, the two push plates 404 can lift the circuit board to a horizontal state, and finally the test module 2 can be lowered to complete the pin detection.

[0045] It should be noted that the gap between the bottom surface of the slider 401 and the bottom surface of the push plate 404 and the top surface of the machine platform 1 (bottom plate 301 ) is very small, which will not affect the movement of the slider 401 and the push plate 404 and will not affect the contact with the circuit board.

[0046] In summary, through the cooperation of the bottom plate 301, the slider 401, the push plate 404 and the rack 405, the circuit board can be lifted to a horizontal state for testing, so as to avoid the circuit board tilting on the machine 1 and affecting the contact of the test module 2, and effectively ensure the overall testing effect. At the same time, the two sliders 401 also have the effect of automatically centering the circuit board when they are relatively close, which can further ensure the testing effect of the circuit board and have higher practicality.

[0047] Embodiment 2:

[0048] See also Figures 1 to 8 On the basis of the first embodiment, considering that the slider 401 will be relatively close to the partition 502 and squeeze the second spring 504 after being attached to the circuit board, the second spring 504 acts on the circuit board through the slider 401. Since the circuit board is usually thin, it may cause squeezing damage to the circuit board, which may affect the quality of the circuit board and subsequent detection results.

[0049] Therefore, the transmission member is improved: the transmission member now includes an inclined rod 505, and the slider 401 includes an upper seat 4011 that slides with the inclined rod 505 and a lower seat 4012 that slides with the upper seat 4011, the lower seat 4012 is set to slide up and down based on the upper seat 4011, and the support rod 403, base 407, push plate 404, gear 406, slot 408 and rack 405 are all placed on the lower seat 4012.

[0050] Furthermore, the upper seat 4011 is slidably matched with the inclined rod 505, so the through hole 402 is placed on the upper seat 4011; at the same time, the inclined rod 505 is tilted downward, and the shape of the through hole 402 is adapted thereto.

[0051] Due to the effect of gravity, the upper seat 4011 and the lower seat 4012 are located at the bottom relative to the inclined rod 505. When the partition 502 drives the inclined rod 505 to move initially, the upper seat 4011 and the lower seat 4012 can be driven to close to the middle synchronously. In order to ensure that the upper seat 4011 and the lower seat 4012 can move synchronously during the initial movement, a plurality of balls (not shown in the figure) are movably embedded at the bottom of the lower seat 4012 to avoid a large friction between the bottom surface of the lower seat 4012 and the bottom plate 301.

[0052] In this embodiment, refer to Figure 8 In order to ensure that the rack 405 can be smoothly reset after moving, and that the upper seat 4011 and the lower seat 4012 can be located at the lowermost position of the inclined rod 505 as a whole in the initial state, a counterweight 409 that fits the rack 405 can be slidably installed inside the slot 408. The counterweight 409 abuts against the end of the rack 405 away from the partition 502 and is located above the rack 405. When the rack 405 moves, it can push the counterweight 409 to rise.

[0053] Through the above design, after the partition 502 drives the upper seat 4011 and the lower seat 4012 to reset, the counterweight 409 can act on the rack 405 to reset it, thereby ensuring that the upper seat 4011 and the lower seat 4012 are reset along the descent of the inclined rod 505, and preventing the self-locking of the gear 406 and the rack 405 from affecting the reset process of the upper seat 4011 and the lower seat 4012. At the same time, the counterweight 409 acts on the rack 405 in the up-down direction, which is different from directly adding weight to the upper seat 4011 or the lower seat 4012, so the extrusion force on the circuit board is still very small, which can further avoid damage to the circuit board.

[0054] When in use, the circuit board can be lifted to a horizontal state for testing through the structures such as the bottom plate 301, the slider 401 and the rack 405, so as to prevent the circuit board from tilting on the machine 1 and affecting the contact of the test module 2. The working process and effect of this part are the same as those in the first embodiment, and will not be repeated here. The difference is that when the cylinder 501 drives the partition 502 to move, the partition 502 drives the upper seat 4011 and the lower seat 4012 to move synchronously through the inclined rod 505. After the lower seat 4012 contacts the circuit board, the upper seat 4011 and the lower seat 4012 can be relatively close to the partition 502 along the inclined rod 505, and the lower seat 4012 can extend downward from the upper seat 4011. In this process, the rack 405 can move along the slot 408 and drive the gear 406 to rotate. The gear 406 still drives the push plate 404 to rotate 180 degrees through the support rod 403, and the movement of the rack 405 can push the counterweight block 409 to rise vertically along the slot 408.

[0055] Compared with the first embodiment, the second spring 504 is replaced by the inclined inclined rod 505 structure through the cooperation of the inclined rod 505, the upper seat 4011, the lower seat 4012 and the counterweight 409, so that the second spring 504 can avoid generating a large clamping force on the circuit board, thereby effectively reducing the extrusion damage to the circuit board and ensuring the overall quality of the circuit board. The overall design is combined with the setting of the transmission part, and will not affect the horizontal lifting of the circuit board by the rotation of the push plate 404. At the same time, because the clamping force on the circuit board is very small, the bending deformation of the circuit board can be avoided, thereby further improving the detection effect of the circuit board, and the applicability is stronger.

[0056] Embodiment three:

[0057] See also Figures 1 to 10 On the basis of the second embodiment, considering that the lower seat 4012 will be relatively close to the partition 502 along the inclined rod 505 after contacting the circuit board, the inclined rod 505 will extend from the through hole 402 of the upper seat 4011 at this time. If the circuit board is a smaller circuit board, the inclined rod 505 may extend from the through hole 402 and be located above the circuit board, thereby affecting the contact test of the test module 2 descending and the circuit board. There are still certain limitations in its use.

[0058] Therefore, the inclined rod 505 and the through hole 402 are improved: the inclined rod 505 now includes a sleeve 5051 fixedly connected to the partition 502, and the inner sliding installation of the sleeve 5051 is provided with an inner rod 5012 that slides with the through hole 402 of the upper seat 4011, and the inner rod 5012 can slide along the sleeve 5051 and will not fall off the sleeve 5051.

[0059] In this embodiment, refer to Fig.10 The through hole 402 is designed to be non-through based on the upper seat 4011. When the upper seat 4011 and the lower seat 4012 are close to the partition plate 502, the end of the inner rod 5012 away from the sleeve 5051 can first abut against the hole wall of the through hole 402, and then slide along the inner wall of the sleeve 5051, and the inner rod 5012 will not extend from the through hole 402.

[0060] When in use, the circuit board can be lifted to a horizontal state for inspection through the structures such as the bottom plate 301, the slider 401 and the rack 405; through the structures such as the inclined rod 505, the upper seat 4011 and the lower seat 4012, the second spring 504 can be avoided from generating a large clamping force on the circuit board, and the extrusion damage to the circuit board can be effectively reduced. The working process and effect of this part are the same as those in the second embodiment, and will not be repeated here. The difference is that when the cylinder 501 drives the partition 502 to move, the partition 502 drives the upper seat 4011 and the lower seat 4012 to move synchronously through the sleeve 5051 and the inner rod 5012. After the lower seat 4012 contacts the circuit board, the upper seat 4011 can move along the inner rod 5012 so that the inner rod 5012 is against the through hole 402, and then the inner rod 5012 can slide along the sleeve 5051, and finally the upper seat 4011 and the lower seat 4012 can still be relatively close to the partition 502.

[0061] Compared with the second embodiment, the coordination of the upper seat 4011, sleeve 5051, inner rod 5012 and through hole 402 can avoid the use of inclined rod 505 extending from the upper seat 4011 above the circuit board, so that the circuit board is in a completely idle state, ensuring good contact between the test module 2 and the circuit board, and further ensuring the overall detection effect. The overall design is combined with the setting of the inclined rod 505, and can be applied to circuit boards of smaller size, thereby relatively increasing the scope of application of the device and meeting more requirements in actual use.

Claims

1. A power-on detection device for an electric energy meter circuit board, comprising a machine platform and a test module arranged on the machine platform for circuit board detection, characterized in that: The machine is provided with a support assembly for supporting the circuit board, and adjustment assemblies are provided on the top of the machine and on both sides of the support assembly, and a control assembly for driving the adjustment assembly is provided on the top of the machine; the two adjustment assemblies can be driven to approach the circuit board through the control assembly, and when the two adjustment assemblies are attached to the circuit board, the circuit board can be lifted in a horizontal state through the control assembly and the adjustment assembly; The support assembly includes a plurality of bottom plates that are slidably matched with the machine platform, the plurality of bottom plates are arranged in a one-to-one corresponding manner, a first spring is fixedly installed between the bottom plates and the machine platform, a groove is provided on the top of the machine platform for accommodating the bottom plates and the first spring, and the first spring makes the top surface of the bottom plates flush with the top surface of the machine platform; The adjustment assembly includes a slider driven by the control assembly and designed in an inverted U shape, a support rod is rotatably mounted at the bottom of the slider, a push plate and a gear are fixedly mounted on the outer surface of the support rod, and a rack that meshes with the gear and is fixedly connected to the control assembly is slidably mounted at the bottom of the slider; When the rack moves and drives the gear to rotate, the gear can drive the push plate to rotate 180 degrees through the support rod. The push plate is in a horizontal state before and after the rotation. After the rotation, the push plate can contact the bottom surface of the circuit board. At this time, the two push plates can lift the circuit board to a horizontal state.

2. A power-on detection device for an electric energy meter circuit board according to claim 1, characterized in that: The rack is designed in two sections, one section is made of hard material and fixedly connected to the control component, and the other section is made of elastic material and connected to the gear transmission; the interior of the slider is provided with a slot for the rack to slide and is designed in an L shape as a whole.

3. A power-on detection device for an electric energy meter circuit board according to claim 2, characterized in that: The control assembly comprises a cylinder fixedly connected to the machine platform, the output shaft of the cylinder is fixedly mounted with a partition fixedly connected to the rack, and the end of the partition away from the cylinder is provided with a transmission member for driving the slider.

4. The power-on detection device for an electric energy meter circuit board according to claim 3, characterized in that: The transmission member comprises a cross bar fixedly connected to the partition plate, a slider is movably sleeved on the outer surface of the cross bar, and a second spring that abuts against the slider is sleeved on the outer surface of the cross bar.

5. The power-on detection device for an electric energy meter circuit board according to claim 3, characterized in that: The transmission member comprises an inclined rod, the slider comprises an upper seat slidably matched with the inclined rod and a lower seat slidably matched with the upper seat, and the support rod, base, push plate, gear, slot and rack are all arranged on the lower seat.

6. A power-on detection device for an electric energy meter circuit board according to claim 5, characterized in that: A counterweight block that fits the rack is slidably installed inside the slot, the counterweight block abuts against the end of the rack away from the partition and is located above the rack. When the rack moves, the counterweight block can be pushed to move up and down along the slot.

7. The power-on detection device for an electric energy meter circuit board according to claim 5, characterized in that: The inclined rod is designed to be inclined downward. When the upper seat moves along the inclined rod, the lower seat can slide up and down based on the upper seat, and a plurality of balls are movably embedded in the bottom of the lower seat.

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