CN116763059A

CN116763059A - Lifting control system of lectern

Info

Publication number: CN116763059A
Application number: CN202210240164.6A
Authority: CN
Inventors: 孙毅
Original assignee: Anhui Zhaoxun Education Management Consulting Co ltd
Current assignee: Anhui Zhaoxun Education Management Consulting Co ltd
Priority date: 2022-03-10
Filing date: 2022-03-10
Publication date: 2023-09-19

Abstract

A lifting control system of a teacher desk comprises a top plate, a pneumatic stay bar, a power rod, a hinge, a cover, a horizontal spring, a connecting nut and a cover end plate, wherein the top plate is attached to the lower side of a horizontal desktop, the pneumatic stay bar and the power rod are vertically fixed on the lower side of the top plate, the hinge is provided with a torsion spring, the cover is fixed on the outer side of the upper end of a main pipe, the horizontal spring is formed by connecting a compression spring and a tension spring, and two ends of the horizontal spring are respectively fixed on a connecting nut and the cover end plate in the middle section of a bolt plate; the upper side and the lower side are respectively provided with a shallow arc groove and horizontally fixed on a fixed plate at the outer side of the upper end of the main pipe, the upper side and the lower side are respectively provided with a flat frame provided with a position hole and used for clamping the fixed plate, two rows of balls corresponding to the position hole and used for clamping the flat frame are respectively arranged, and the upper side and the lower side are respectively provided with a bolt plate for clamping the two rows of balls. The bolt plate does not generate friction resistance with the cover cap and the main pipe in the operation process of the design, and the lifting smoothness and the service life of the teacher desk are greatly improved.

Description

Lifting control system of lectern

Technical Field

The invention relates to a teacher's desk in a classroom of middle and primary schools, in particular to a lifting control system of the teacher's desk.

Background

In general schools and schools in China, in order not to obstruct the vision of students at the back row, the common practice of seat arrangement is that students with shorter stature sit at the front row. The teaching content on the blackboard and the teaching content presented by the display screen (or the electronic whiteboard and the like) of the informationized teaching integrated machine are blocked by the lectern on the podium (the combined height of the ground podium and the lectern is generally about 105-115 cm), and the desk height of students in classrooms is generally about 70cm and the bench height is about 40 cm. Thus, the students with shorter statutes sitting in the front row of the classroom have difficulty in seeing and reading the lower layout of the blackboard. Especially in the primary school stage of the obligatory education, the students with the difficulty in reading are relatively larger in proportion.

Chinese patent 202122100721.8 provides a liftable lectern design scheme, which includes: liftable lectern main part, the fixed position internal periphery of lower part that horizontal desktop and top board are synthesized, and be located their inside: (1) the power output mechanism for lifting the teacher desk, namely an operator manually presses down the center of the horizontal desktop (above the axis of the pneumatic supporting rod), the teacher desk main body descends, meanwhile, pressure is conducted to the top plate, and the power rod and the rotating plate connected to the top plate descend along with the top plate; the pneumatic supporting rod always bears the gravity of the teacher's desk main body, the supporting rod of the pneumatic supporting rod is sunk into the air cylinder by the manual pressure of an operator, and the resilience force is accumulated as the power for pushing the teacher's desk main body to return to the traditional height (the falling essence of the teacher's desk main body is that the manual pressure of the operator is larger than the difference value between the lifting force of the pneumatic supporting rod and the gravity of the teacher's desk main body; after the manual pressure of the operator is withdrawn, the rebound lifting force of the pneumatic supporting rod is larger than the gravity of the teacher's desk main body, so that the teacher's desk main body can fully ensure to return to the traditional height); (2) the control mechanism for the descending locking and unlocking of the table main body consists of a top plate, a pneumatic stay bar, a power rod, a rotating plate, a main pipe, a cover cap, a horizontal spring, a bolt plate, a tail ring (special-shaped ring) and a hinge with a torsion spring, and realizes the static locking of the table main body after the specified amount of descending and the self-ascending of the unlocked table main body to return to the traditional highly stable working state by means of the organic chain reaction; (3) the support mechanism for guiding the teacher desk body to vertically lift is positioned below the center of the horizontal desktop and at four corners in the teacher desk body, and each support mechanism is composed of a suspension rod vertically fixed on a top plate, a guide head fixed at the lower end of the suspension rod and a main pipe containing the guide head in an inner cavity; (4) and the signal mechanism is used for enabling the teacher desk main body to descend to a specific preset position.

The lifting control mechanism is the core of the 202122100721.8 patent design, and based on the L-shaped section structure of a specific section of a bolt plate disclosed by the 202122100721.8 patent, two phenomena appear in the test and manufacture detection of a relevant prototype: (1) because the contact surface between the lower bottom horizontal surface of the bolt plate and the partial horizontal surface of the cover cap is larger, in the process of the teacher's desk descending and reaching the locking state, in order to push the bolt plate to horizontally displace so that the front section of the bolt plate is inserted into the middle opening of the rotating plate, the vertical pressure applied to the upper inclined surface of the tail ring of the bolt plate by the power rod is converted into the vertical pressure to the partial horizontal surface of the cover cap in an ultra-large proportion, and the friction resistance between the bolt plate and the cover cap in the displacement of the bolt plate is greatly increased; (2) because the vertical section of the bolt plate contained in the cover is longer, in the process of lifting and unlocking the teacher's desk, in order to push the bolt plate to horizontally displace so that the front section of the bolt plate is separated from the middle opening of the rotating plate, the upward pressure applied to the lower inclined surface of the tail ring of the bolt plate by the power rod (endowed by the pneumatic supporting rod) is converted into the upward pressure of the linear top surface (the width is generally larger than 2 mm) of the bolt plate to the upper side plane of the cover in a certain proportion, and the friction resistance in the process of horizontally displacing the bolt plate is also generated. Both the above situations result in a lectern body that is not smooth enough to move up and down and that is more operational and force-applying than preset.

Disclosure of Invention

The invention aims to provide a reliable lifting control system for a teacher's desk in a primary and secondary school classroom, so as to achieve the purposes of labor saving operation and smooth lifting of the teacher's desk.

The design scheme is as follows: the utility model provides a lifting control system of lectern, including the roof that the laminating of horizontal desktop downside is fixed, roof downside is upright fixed pneumatic stay and power pole, the upper end of one page laminating roof, another page fixed connection revolving plate of hinge, this hinge has the torsional spring, is responsible for the upper end outside and is fixed with the shroud, contains the middle section of pegboard between shroud and the person in charge, the one end that the pegboard corresponds the power pole is fixed with the tail ring, the spring both ends of lying on a bed are fixed in pegboard middle section and shroud end plate respectively, still including:

(1) the upper side and the lower side are respectively provided with a shallow arc groove and are horizontally fixed on a fixed plate at the outer side of the upper end of the main pipe,

the upper side and the lower side are respectively provided with a positioning hole and a flat frame for clamping the fixing plate,

two rows of balls corresponding to the positioning holes and wrapping the flat frame,

bolt plates for clamping two rows of balls in upper and lower shallow arc grooves;

(2) the horizontal spring is formed by connecting a compression spring and a tension spring, long openings are formed in the horizontal planes of the upper side and the lower side of the cover, and the pin rod penetrates through the upper long opening, the lower long opening and the horizontal spring of the cover and is suitable for horizontal displacement in the long openings.

The acute included angle between the upper inclined surface of the bolt plate tail ring and the horizontal plane is not smaller than 45 degrees.

The middle section of the bolt plate is fixedly provided with a connecting nut, and one end of the horizontal spring is fixedly connected with the connecting nut.

The middle section of the pin rod is connected between the supporting ring at the end part of the stretching spring and the effective stretching ring in a penetrating way.

The self-defined maximum expansion angle of the hinge is 90 degrees, and the torsion spring maintains the maximum expansion shape of the hinge.

In this design scheme, fixed plate, ball, flat frame, key board, tail ring have constituted the compound key body among the lectern lift control system, and the series ball that is located compound key body upside and downside all is surrounded by the shallow arc groove of key board and the shallow arc groove of fixed plate that is relative and give birth to, and the centre of sphere wiring direction of series ball is the horizontal migration direction of key board promptly. Still because the relative interval in key board shallow arc groove, fixed plate shallow arc groove, ball diameter and key board, fixed plate, the overall setting of flat frame three clearance for the key board can not drop from the series ball, and the ball can not deviate from the position hole of flat frame and fixed plate shallow arc groove, and whenever the key board all does not touch the shroud, does not touch the person in charge. When the power rod (lower flat head) applies pressure to the upper inclined surface or the lower inclined surface of the tail ring of the bolt plate, the pressure is accurately converted into thrust for horizontal displacement of the bolt plate according to a preset proportion, and the bolt plate smoothly realizes horizontal displacement (rolling of balls on a flat frame position hole and integral displacement of a flat frame are used therebetween), and the displacement is the displacement relative to the power rod and the displacement relative to the (middle opening of the) rotating plate.

During the above operation of the present design: the frictional resistance of the latch plate, the cover cap and the main pipe in the prior 202122100721.8 patent is completely eliminated; along with the bidirectional horizontal displacement of the bolt plate under the control of external force, the bolt plate drives the balls to roll along the shallow arc grooves of the fixed plate, and the balls also drive the flat frame to do horizontal linear displacement, but the structures at the two ends of the fixed plate have preset final limit on the displacement of the flat frame.

The spring formed by connecting the compression spring and the tension spring can be called a double-function spring of the design.

Since the cover is fixed to the main pipe (outside the upper end), one end of the double-acting spring is fixed to the cover (end plate), and the other end is fixed to the bolt plate (the connecting nut positioned at the middle section), the static length of the double-acting spring determines the position of the bolt plate relative to the main pipe, the cover, the power rod and the rotating plate, and the position is also the static initial position of the bolt plate in a left-right direction displacement mode.

When an operator pushes down the center of the horizontal plane of the teacher desk (the center corresponds to the upper end of the pneumatic stay bar fixed on the lower side of the top plate), the pressure makes the power bar and the rotating plate descend through the top plate; in the continuous descending process of the power rod, the upper inclined surface of the tail ring receives downward pressure conducted by the power rod, the bolt plate is pushed to horizontally displace towards the front end direction by means of the balls, the flat frame and the fixed plate fixed on the main pipe, namely, the connected nut piece fixed on the middle section of the bolt plate pushes the tension spring, the push pin rod and the push compression spring, the compression spring is compressed according to a preset amount (the front end of the compression spring is fixed on the end plate of the cover cap and is not movable) until the front end of the bolt plate is locked by the vertical buckling of the middle opening of the rotating plate, and at the moment, the stable working state is obtained after the main body of the lectern is lowered (the lower flat head of the power rod is still attached to a certain position of the upper inclined surface of the tail ring).

Subsequently, when the operator pushes down the center of the horizontal desktop again by hand, the buckling of the middle opening of the rotating plate to the front end of the bolt plate from bottom to top is released, the compression spring which is compressed before releases the anti-elasticity force, and the tension spring pushes the conjoined nut, namely the bolt plate to horizontally displace towards the tail ring direction (wherein, the pin rod returns to the long opening end position of the cover cap, and the compression spring returns to the static state); when the power rod is lowered to the lowest position, the operator with no lowering hand feel withdraws from manual pressing on the tabletop, the lifting force exerted by the pneumatic stay rod still exists, the lower flat head of the power rod in the ascending state is pressed against the lower inclined surface of the tail ring of the bolt plate, (the horizontal thrust converted by the lifting force of the pneumatic stay rod) to force the bolt plate to continuously retreat, and the tension spring is continuously stretched by taking the pin rod as a starting point (also because of the limitation of the long opening of the cover cap on the pin rod, and the compression spring is not stretched at the moment) until the front end of the bolt plate completely withdraws from the neutral opening of the rotating plate and a preset safety distance is obtained. Thereafter: (1) the lifting force given by the pneumatic stay bar enables the top plate to continuously rise, the rotating plate and the power bar quickly rise to the upper part of the bolt plate, and then the teacher's desk main body returns to the traditional highest position; (2) the stretching spring stretched before releases the reactive force after losing the flat head pushing force under the power rod, and pulls the bolt plate to return to the initial position through the conjoined nut, so that the double-function spring is in the initial static state again.

The working flow of the compression spring and the extension spring corresponding to one lifting cycle of the teacher's desk body is as described above.

The positive effect of this design: the composite bolt body constructed by the fixed plate, the ball, the flat frame, the bolt plate and the like completely eliminates the friction resistance between the bolt plate, the cover cap and the main pipe before, and the lifting smoothness of the teacher desk is greatly improved. By means of the combination of the compression springs and the extension springs, the compression springs are compressed only and the extension springs are not damaged in the process of lowering and locking the teacher's desk main body by means of the displacement of the pin rod and the limit, and the extension springs are stretched only and the compression springs are not damaged in the process of unlocking and lifting the teacher's desk main body, so that the service life of the double-function springs is greatly prolonged. The design mechanism is totally hidden in the desk body, has no electric device, no electricity distribution and no noise, an operator presses the center of the horizontal desktop for the first time, namely, the height is lowered and locked, and the teacher's desk body is returned to the traditional height by short-range pressing and unlocking again, so that the lifting response speed is high, and the near-intelligent lifting effect is obtained by means of the setting of the semi-automatic executing mechanism.

Drawings

Fig. 1a is a front view of a composite plug of a lifting lectern control system, fig. 1b is an exploded view of a composite plug construction, fig. 1c is a rear view of a composite plug construction, and fig. 1d is an exploded view of a composite plug construction corresponding to the view angle of fig. 1 c.

Fig. 2a is a cross-sectional view of the key plate of the present design, fig. 2b is a flat frame visual view, fig. 2c is a schematic cross-sectional view of the flat frame with balls arranged thereon, and fig. 2d is an end view of the fixed plate.

Fig. 3a is a schematic view of a fixing manner of the fixed plate on the outer side of the upper end of the main pipe, fig. 3b is a schematic view of an assembling position of the flat rack and the ball on the fixed plate and the main pipe, fig. 3c-d are schematic views of assembling the bolt plate, the fixed plate, the flat rack and the ball on the main pipe under different view angles, fig. 3e is a schematic view of a cross section of the bolt plate, the flat rack, the fixed plate and the ball assembly in the composite bolt body, and fig. 3f is a schematic view of a plane of the relative position relationship of the assembly of fig. 3e and the main pipe, the cover cap, the tension spring and the pin rod.

Fig. 4a is an exploded view of a latch plate, a tail ring, a union nut, a cover cap, and a pin assembly from another perspective, fig. 4b is a schematic plan view of a compression spring, fig. 4c is a schematic plan view of a tension spring, fig. 4d is a schematic plan view of a double-function spring of the present design, fig. 4e is a schematic view of a state in which one end of the double-function spring is fixed to a middle union nut member of the latch plate, and fig. 4f is a schematic view of a state in which the other end of the double-function spring is fixed to an end plate of the cover cap.

Fig. 5a-b are schematic views of the lifting control system when the power rod initially contacts the upper inclined surface of the tail ring under different angles, and fig. 5c is a partial enlarged view of fig. 5b focusing on the dual-function spring.

Fig. 6a is a schematic view of a state of the lifting control system when the compression spring is fully compressed, fig. 6b is a partially enlarged view of fig. 6a, which takes the double-acting spring as an important point, fig. 6c is a schematic view of a locking state of the lifting control system, fig. 6d is a partially enlarged view of fig. 6c, which takes the double-acting spring as an important point, and fig. 6e is a schematic view of a relative positional relationship between the flat frame and the fixed plate in the state of fig. 6 c.

Fig. 7a is a schematic view of a lifting control system state when the compression spring is compressed at the maximum amplitude, fig. 7b is a partially enlarged view of fig. 7a taking the double spring as a focus, fig. 7c is a schematic view of a relative position relationship between the flat frame and the fixed plate in the state of fig. 7a, fig. 7d-e are schematic views of a lifting control system state when the tension spring is stretched at the maximum amplitude under different view angles, fig. 7f is a partially enlarged view of fig. 7d taking the double spring as a focus, and fig. 7g is a schematic view of a relative position relationship between the flat frame and the fixed plate in the state of fig. 7 e.

Fig. 8 is a simplified schematic diagram of a liftable lectern of the present design at a conventional height.

Detailed Description

Examples. See fig. 8, fig. 5a-b: the lifting teacher's desk comprises a teacher's desk body formed by a horizontal desktop and an upper coaming and an inner periphery at a lower fixing position, wherein the lifting of the teacher's desk refers to the lifting of the teacher's desk body. The lifting control system of the design belongs to an internal structure of a lectern, and comprises a top plate (21) attached and fixed on the lower side of a horizontal tabletop (11), a pneumatic supporting rod (12) and a power rod (22) (the lower end of the pneumatic supporting rod (12) is in contact with the ground of the lectern in an abutting mode), a hinge (23) carrying a torsion spring (231) is included, one page of the hinge is attached to the top plate (21), the other page of the hinge is fixedly connected with the upper end of a rotating plate (24), and the maximum expansion angle of the hinge (23) is 90 degrees. Note that fig. 8 is a simplified schematic diagram of the lifting teacher's desk of the present design at a conventional height, the lower end of the rotating plate (24) has a significant distance from the peg plate (6) (front end slope), and the lower end of the power rod (22) has a significant distance from the tail ring (71); in fig. 5a-b, the lower end of the rotating plate (24) is contacted with the slope of the front end of the bolt plate (6), and the lower end of the power rod (22) is contacted with the upper slope (71) of the tail ring.

The lifting control system of the present design also comprises a steel flat frame (4), balls (5), a fixed plate (3) and a bolt plate (6) and a tail ring (71) which can be an injection-molded part, and together form a so-called composite bolt body (see fig. 1 a-d). Referring to fig. 2a-d and 3e, the upper side and the lower side of the fixed plate (3) are respectively provided with an externally-directed shallow arc groove (31), the flat frame (4) is used for clamping the fixed plate (3), the upper side and the lower side of the flat frame (4) are respectively provided with a series of positioning holes (41), two rows of balls (5) corresponding to the positioning holes (41) are used for clamping the flat frame (4), and the upper side and the lower side of the bolt plate (6) are respectively provided with an internally-directed shallow arc groove (61) for clamping the two rows of balls (5). It is evident from fig. 2a that the design peg board (6) has a different form from the original peg board in the 202122100721.8 patent, and that the two are distinct in overall configuration, in particular in cross-sectional configuration.

See fig. 3a-d, fig. 3e-f: the fixed plate (3) is horizontally fixed on the outer side surface of the upper end of the main pipe (13), and the composite bolt body integrally belongs to the main pipe (13). From the above, the series balls (5) respectively positioned at the upper side and the lower side of the composite bolt body are surrounded by the corresponding bolt plate shallow arc groove (61) and the fixed plate shallow arc groove (31), and the direction of the connecting line (straight line) of the ball centers of the series balls (5) is the horizontal reciprocating displacement direction of the bolt plate (6). Due to the relative spacing of the bolt plate shallow arc grooves (61), the fixed plate shallow arc grooves (31), the diameters of the balls (5) and the clearance of the bolt plate (6), the fixed plate (3) and the flat frame (4), the bolt plate (6) cannot fall off from the series of balls (5), and the balls (5) cannot fall off from the flat frame position holes (41) and the fixed plate shallow arc grooves (31).

( Fig. 3a-d are merely layered illustrations of composite plugs, it being evident that fig. 3b is not an illustration of a specific assembly process, and the relevant assembly process steps may be: the flat frame (4) is horizontally placed, and in the process of sleeving and inserting the bolt plate (6) into the flat frame (4), the balls (5) on two sides are sequentially filled into the flat frame positioning holes (41) pair by means of special tools until the flat frame (4) carrying full balls is completely sleeved and covered by the bolt plate (6). )

In the composite bolt structure, the upper inclined surface (711) of the tail ring and the space horizontal plane form an acute angle, and the acute angle is suitable for being valued in the interval of [45 degrees, 60 degrees ] in order to reduce the consumption of manual pressure of an operator. See fig. 5a-b: when the lower flat head (221) of the power rod applies downward pressure to the upper inclined surface (711) of the tail ring, the pressure is accurately converted into thrust for horizontally displacing the bolt plate (6) according to a preset proportion (the same is the same as the situation when the lower flat head (221) of the power rod applies upper pressing force to the lower inclined surface (712)). But the smooth realization of the horizontal displacement of the bolt plate (6) is realized, the rolling of the balls (5) on the flat frame position holes (41) is also beneficial to the integral displacement of the flat frame (4) along the shallow arc grooves (31) of the fixed plate, and the displacement is the displacement relative to the power rod (22) and the central opening (241) of the rotating plate. The composite bolt body structure mode and the pushing mode of the bolt plate (6) displacement of the design are fully paid attention to labor saving.

See fig. 4a and compare fig. 5a-b: the union nut (72) is an injection-molded part which can be fixed to the front middle section of the latch plate (6) at least by means of a strong adhesive. See fig. 4b-d: the compression spring (81) and the tension spring (82) are connected into a whole, namely a so-called double-function spring. See fig. 4e-f: one end of the double-acting spring is fixed on the conjoined nut (72) in advance, the other end of the double-acting spring is fixed on the cover end plate (91), the cover (9) is fixed on the outer side face of the upper end of the main pipe (13), at the moment, the middle section of the bolt plate is contained in the cover (9), the positions of the double-acting spring, the main pipe (13), the bolt plate (6), the pin rod (93) and other parts are as shown in fig. 3f, and therefore, the bolt plate (6) is not contacted with the cover (9) and the main pipe (13) whenever. Even in the whole process that the lower flat head (221) of the power rod presses the upper inclined surface (711) of the tail ring or the upper top presses the lower inclined surface (712) and the bolt plate (6) makes left-right displacement.

(to increase the reliability of the horizontal directional movement of the bolt plate (6) pushed by the compression spring (81) or pulled by the tension spring (82), the double-function spring is arranged to be 2 parallel branches horizontally, and of course, only 1 double-function spring is needed theoretically.

See fig. 4c-d: the pin rod (93) is allowed to pass through the first ring (supporting ring) and the second ring at the butt joint end of the extension spring (82) and the compression spring (81), and the other effective rings are tightly combined (the equal spacing which is not tight can be adopted, but the spacing is smaller). Correspondingly, the upper side plane and the lower side plane of the cover cap (9) are respectively provided with long openings (92), and the pin rods (93) penetrate through the long openings (92) at the two sides and are suitable for horizontal displacement in the long openings (92). In addition: secured to the union nut (72) is one end of a tension spring (82) and attached to the cap end plate (91) is one end of a compression spring (81), see fig. 4e-f.

Obviously, the lifting control system also comprises a double-function spring synthesized by the compression spring (81) and the tension spring (82), and comprises a main pipe (13), a cover cap (9), a pin rod (93) and a conjoined nut (72).

The overall elevation control system is seen in fig. 5a-b.

The following is a segmental description of the lifting situation of the lectern body:

1. initial lowering of the body of the desk

See fig. 8: when the horizontal desktop (11) is in a traditional high position, an operator manually presses down the center of the horizontal desktop (above the axis of the pneumatic supporting rod (12)) to overcome the upward pressing force of the pneumatic supporting rod (12), and the teacher's desk main body is vertically lowered under the assistance of the related guide and guarantee mechanism, namely the top plate (21) and the power rod (22) and the rotating plate (24) vertically connected with the lower side of the top plate are lowered until the lower flat head (221) of the power rod contacts the upper inclined surface (711) of the tail ring, and meanwhile the lower bottom of the rotating plate (24) contacts the front end slope of the bolt plate (6) (see fig. 5 a-b). At this time, the compression spring (81) is not compressed, the tension spring (82) is not stretched, and the whole double-function spring is in a static state (see fig. 5 c); the length of the double-function spring determines the relative positions of the bolt plate (6), the rotating plate (24), the cover cap (9) and the power rod (22), and the positions are the initial positions of the subsequent left and right displacement of the bolt plate (6); at this time, the hinge still presents a maximum unfolding angle of 90 degrees, the torsion spring (231) effectively maintains the standard state of the vertical top plate (21) of the rotating plate (24) (see fig. 5a, in order to fully ensure the standard vertical top plate (21) of the rotating plate (24), the design is provided with 2 torsion springs (231). In addition, the sound tube (14) which is the same as the lower section of the rotating plate (24) and is fixed on the upper end side surface of the main tube (13) can force the rotating plate (24) to accurately vertical top plate (21)) in preparation.

2. Obtaining and locking stable working state of teacher's desk body after lowering height

On the basis of fig. 5a-b, the operator continues to manually push down the center of the tabletop (above the axis of the pneumatic stay (12), overcomes the upward pushing force of the pneumatic stay (12)), the top plate (21) together with the power rod (22) and the rotating plate (24) continues to descend, the power rod lower flat head (221) generates a forced pressure on the tail ring upper inclined surface (711), the forced pressure is decomposed into a horizontal component and a vertical component, the horizontal component forces the bolt (6) to horizontally displace towards the front end direction by the tail ring upper inclined surface (711), the displacement then pushes the rotating plate (24) to rotate around the axis of the hinge (23) (left rotation in fig. 6 a), the included angle between the two end lines of the torsion spring is continuously reduced (within an acute angle range), fig. 6a expresses the instant state when the lower line of the middle opening (241) of the rotating plate is lower than the lower side of the bolt (6), and the compression spring (81) is greatly compressed, but the tension spring is still in a static state (the effective rings are in a tight state, see fig. 6 b).

When the line below the middle opening (241) of the rotating plate is lower than the lower side of the bolt plate (6), the front end of the bolt plate (6) loses the pushing of the counter rotating plate (24) (the lower end), the rebound force released by the compressed torsion spring (231) rapidly before pushes the rotating plate (24) to flush back (return) to the vertical state with the top plate (21) (the rotating plate (24) sends out a reset sound signal when impacting the sound tube (14), and then an operator withdraws from manually pressing the horizontal desktop (11); because the lift force of the pneumatic stay bar (12) pushing the top plate (21) upwards is constant, the front end of the latch plate (6) is buckled up by the middle opening (241) of the rotary plate from bottom to top (see fig. 6 c), and the rebound force of the compressed compression spring (81) is insufficient to push the latch plate (6) to separate from the buckling of the middle opening (241) of the front end of the rotary plate, the current state is self-maintained, namely the latch plate (6) is locked, the lower flat head (221) of the power bar naturally stays at a position of the upper inclined surface (711) of the tail ring (the horizontal thrust of the latch plate (6) is balanced with the rebound force of the compression spring (81), and the locked state is the stable working state after the height of the teacher's desk body is lowered. At this time, the state of the double-acting spring can be partially seen in fig. 6 d; the relative positions of the flat frame (4) and the balls (5) and the fixed plate (3) are shown in fig. 6e.

3. Unlocking and returning to traditional height of locked state of teacher's desk main body

If the teacher's desk body is intended to return to the traditional high position, on the basis of fig. 6c, the operator manually presses down the center of the desk top again (above the axis of the pneumatic stay (12), overcoming the upper pressing force of the pneumatic stay (12)), the lower flat head (221) of the power rod slides down to the lowest section of the outer vertical face (713) (see fig. 7 a) by fitting the upper inclined surface (711) of the tail ring, at this time, the front end of the bolt plate (6) is still contained in the middle opening (241) of the rotating plate, the tension spring (82) is static, the compression spring (81) is in the maximum amplitude compression state (see fig. 7b for part), and the relative positions of the flat frame (4) and the fixed plate (3) are shown in fig. 7c (the fixed plate end gate (32) as a forced guarantee structure), so that the possibility that the flat frame (4) and the ball (5) fall off from the end of the fixed plate (3) is avoided.

Continuing to manually press the center of the desk until the desk body is not lowered due to the fact that the operator is not pressed, and at the moment, the support rod (121) at the upper section of the pneumatic support rod is completely sunk into the air cylinder (122) at the lower section, namely the allowable lowering limit is reached; at this moment, the lower flat head (221) of the power rod is positioned below the tail ring (71) and is completely separated from the tail ring (71), namely, the pushing of the tail ring (71) is lost, the maximum elastic force accumulated before the (2) compression springs (81) rapidly pushes the latch plate (6) to return to the initial static position, but the front end of the latch plate (6) is still not completely separated from the rotating plate neutral opening (241) (but the manual pressure on the horizontal tabletop (11) is withdrawn at this moment), the lift force of the constantly existing pneumatic supporting rod (12) pushes the lower flat head (221) of the power rod to contact the lower inclined surface (712) of the tail ring from bottom to top, at this moment, the compression springs (81) are not compressed, the tension springs (82) are not stretched, the whole double-function springs are still static (see fig. 5 c), and the relative positions of the flat frame (4), the balls (5) and the fixed plate (3) are returned to fig. 3 b.

The situation is that the tail ring is pushed by the lifting force of the pneumatic stay bar (12), the lower flat head (221) of the power bar continuously rises until the tail ring is contacted with the lower inclined surface (712) of the tail ring and is always contacted with the tail ring and continuously rises, meanwhile, the tail ring (71), the bolt plate (6) and the conjoined nut (72) are continuously horizontally displaced towards the rear end of the bolt plate (6) by the horizontal component force generated by the action of the lower flat head (221) of the power bar on the lower inclined surface (712) of the tail ring, and the tension spring (82) starts to be continuously stretched (but the compression spring (81) is not stretched and is stably in a static state due to the limitation of the long opening (92) of the housing on the pin bar (93); when the lower flat head (221) of the power rod is completely separated from the lower inclined surface (712) of the tail ring and is abutted against (reaches the lower section of the inner vertical surface (714) of the tail ring, the front end of the bolt plate (6) is completely separated from the middle opening (241) of the rotating plate and keeps a safe distance from the middle opening (see fig. 7 d), the stretching spring (82) reaches the maximum stretching (see fig. 7e for part), and the relative position relation between the flat frame (4), the ball (5) and the fixed plate (3) is shown in fig. 7f (obviously, the fixed plate end flashboard (32) eliminates the possibility of unexpected falling of the flat frame (4); the lifting force of the pneumatic stay bar (12) continuously pushes the top plate, the lower flat head (221) of the power bar continuously rises to the upper section of the inner vertical surface (714) of the tail ring against the inner vertical surface (714) of the tail ring, the front end of the bolt plate (6) is separated from the middle opening (241) of the rotating plate and keeps a safe distance with the middle opening, the middle opening (241) of the rotating plate is positioned above the slope of the front end of the bolt plate (6), and the lower flat head (221) of the power bar continuously and rapidly rises to the upper side of the bolt plate (6) without difficulty. At this time, the state of the double-function spring is still shown in fig. 7f, and the relative position relationship between the flat frame (4) and the fixed plate (3) is still shown in fig. 7 g.

And then, the pneumatic stay bar (12) pushes the lower flat head (221) of the power bar to continuously lift and separate from the contact with the tail ring (71), the rebound force accumulated by the maximum stretching of the stretching spring (82) before the stretching spring is suddenly released, and the rapidly folded stretching spring (82) pulls the conjoined nut (72) to horizontally displace and the bolt plate (6) to horizontally displace until the original static position is returned. At this time, the double-function spring is in original static state, and the relative position relationship between the flat frame (4) and the fixed plate (3) is shown in fig. 3 b. The pneumatic brace (12) will also continue to push the top plate (21) up until the table body returns to the conventional high position, and the rotating plate (24) and power rod (22) of the vertical top plate also return to the conventional high position, as shown in fig. 8.

Continuing to be illustrative is:

in a complete working cycle of lifting and lowering the teacher desk, any section of the teacher desk body is manually pressed by an operator, but all the pressing stores rebound energy for the pneumatic supporting rod (12), rebound energy for one of the double springs or rebound energy for the torsion spring (231). When the manual pressing of an operator is withdrawn, the rebound force released by the pneumatic supporting rod (12) pushes the teacher desk main body to rise to the traditional high position, and the teacher desk is in a locking state of stable work after the height is reduced; the rebound force released by one spring in the double-function spring pushes the latch plate (6) to return to the initial position; the rebound force released by the torsion spring (231) pushes the rotating plate (231) back to the original vertical top plate state. In the whole working period of the lifting control system, the power rod (22) serves as a direct operator for pulling the tail ring (71) by descending pressure and ascending lifting force, the running track of the power rod is on a vertical straight line (or a vertical plane), and the running track of the bolt plate (6) is always on a horizontal straight line (or a horizontal plane).

See fig. 8: the weight of the teacher desk main body is a fixed value, and the lifting force of the pneumatic supporting rod (12) is greater than the gravity of the teacher desk main body. Starting from the manual pressing of the horizontal tabletop (11) by an operator, until the teacher's desk body returns to the traditional height, the pneumatic supporting rod (12) always provides upward lifting force for the top plate (21). When the pressing force of an operator to the table top is larger than the difference between the lifting force of the pneumatic supporting rod (12) and the weight of the teacher's desk main body, the teacher's desk main body is in a descending process; when the pressing force is removed, the table body is in the ascending process (except the locked time period). The pneumatic stay bar (12) is widely sold in the current market, and the difference between the lifting force and the gravity of the teacher desk main body can be preset in the production process.

In the current classroom of middle and primary schools, the distance between the first horizontal student desk and the blackboard is generally about 2m, and the first horizontal student desk accords with the national standard about the use of the student desks and stools; the height of the ground platform is generally 18-25cm, and the height of the horizontal desktop of the traditional lectern above the platform is generally about 85cm. In the designed product, when the traditional teacher desk (main body) descends by about Cheng Da cm, the problem that all students read the whole blackboard surface without obstacle can be widely solved; if the horizontal table top is continuously pressed to be lowered by about 10cm (namely, withdrawn), the lifting control mechanism is automatically unlocked subsequently, and the teacher's desk (main body) automatically and stably returns to the initial height; a single pass of the descent lock or ascent back to the conventional height takes about 3 seconds.

As can be seen from the 202122100721.8 patent specification, the spring is compressible and stretchable, so that the service life of the spring is relatively short under the requirement, and even if a specific heat treatment process is adopted, the service life is still different from an ideal level except that the process is quite complex.

In general, the double-function spring between the cover cap (9) and the bolt plate (6) can be turned around integrally (the positioning of the pin rod is changed correspondingly), but the specific application effect is not better than that of the embodiment.

Claims

1. The utility model provides a lifting control system of lectern, including the roof that the laminating of horizontal desktop downside is fixed, roof downside is upright fixed pneumatic stay and power pole, the upper end of one of them laminating roof of hinge, another page of fixed connection revolving plate, this hinge has the torsional spring, be responsible for the upper end outside and be fixed with the shroud, contain the middle section of pegboard between shroud and the person in charge, the one end that the pegboard corresponds the power pole is fixed with the tail ring, the spring both ends of lying on a bed are fixed in pegboard middle section and shroud end plate respectively, its characterized in that still includes:

(1) the fixed plate is fixed on the outer side of the upper end of the main pipe, the upper side and the lower side of the fixed plate are respectively provided with a shallow arc groove,

the flat frame is wrapped and clamped with the fixing plate, the upper side and the lower side are respectively provided with a locating hole,

two rows of balls corresponding to the positioning holes are wrapped and clamped on the flat frame,

the shallow arc grooves on the upper and lower sides of the bolt plate are wrapped with two rows of balls;

2. The lifting control system of a lectern according to claim 1, wherein the acute angle between the inclined surface of the tail ring of the peg board and the horizontal plane is not smaller than 45 degrees.

3. The lifting control system of the teacher's desk as claimed in claim 1, wherein a connecting nut is fixed at the middle section of the bolt plate, and one end of the horizontal spring is fixedly connected with the connecting nut.

4. The lifting control system of the teacher's desk as claimed in claim 1, wherein the middle section of the pin rod is connected between the tension spring end supporting ring and the effective tension ring in a penetrating way.