WO2018076943A1 - 一种新型升降桌 - Google Patents

一种新型升降桌 Download PDF

Info

Publication number
WO2018076943A1
WO2018076943A1 PCT/CN2017/101350 CN2017101350W WO2018076943A1 WO 2018076943 A1 WO2018076943 A1 WO 2018076943A1 CN 2017101350 W CN2017101350 W CN 2017101350W WO 2018076943 A1 WO2018076943 A1 WO 2018076943A1
Authority
WO
WIPO (PCT)
Prior art keywords
sleeve
gas spring
assembly
motor
screw
Prior art date
Application number
PCT/CN2017/101350
Other languages
English (en)
French (fr)
Inventor
成武
Original Assignee
成武
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 成武 filed Critical 成武
Publication of WO2018076943A1 publication Critical patent/WO2018076943A1/zh

Links

Images

Classifications

    • AHUMAN NECESSITIES
    • A47FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47BTABLES; DESKS; OFFICE FURNITURE; CABINETS; DRAWERS; GENERAL DETAILS OF FURNITURE
    • A47B13/00Details of tables or desks
    • AHUMAN NECESSITIES
    • A47FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47BTABLES; DESKS; OFFICE FURNITURE; CABINETS; DRAWERS; GENERAL DETAILS OF FURNITURE
    • A47B13/00Details of tables or desks
    • A47B13/08Table tops; Rims therefor
    • AHUMAN NECESSITIES
    • A47FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47BTABLES; DESKS; OFFICE FURNITURE; CABINETS; DRAWERS; GENERAL DETAILS OF FURNITURE
    • A47B9/00Tables with tops of variable height

Definitions

  • the utility model relates to the technical field of furniture, in particular to a novel lifting table.
  • the automatic lifting table is generally powered by electricity.
  • the motor control device is used to adjust the height of the lifting table.
  • the existing lifting table on the market is often unbalanced during the lifting process. After a certain period of time, the plastic tube plug with the inner jacket is used. If the wear gap is too large, the table will be shaken or tilted forward; the lifting screw will work under high load for a long time, which will shorten the service life of the screw; the DC motor for lifting and lowering will work under high load for a long time, reducing the motor. The service life increases the energy of the motor.
  • the purpose of the utility model is to provide a novel lifting table with simple structure, stable lifting and low energy consumption to solve the problems raised in the above background art.
  • a new type of lifting table comprising a table body and a supporting mechanism, the inside of the table body is a hollow structure, the table body is provided with a DC motor box and a DC motor; the DC motor Fixedly installed inside the DC motor box; the DC motor box is provided with a through hole near the lower bottom surface of the side of the frame; the DC motor box is provided with a transmission short shaft, and the transmission short shaft is connected with the rotating shaft end of the DC motor;
  • the supporting mechanism is provided with a lifting device, a cross bar and a base; both ends of the cross bar are equipped with lifting devices, and the cross bar is fixedly connected with the lifting device; the lifting device is composed of a sleeve assembly, a screw assembly and a gas spring assembly;
  • the sleeve assembly is provided with an inner sleeve, an outer sleeve, an inner sleeve plug and an outer sleeve plug; the upper end of the inner sle
  • the size of the through hole formed in the lower surface of the DC motor case matches the size of the upper end of the inner sleeve.
  • the outer diameter of the lower end of the screw rod matches the inner diameter of the screw sleeve.
  • the outer diameter of the lower end of the gas spring is matched with the inner diameter of the gas spring sleeve.
  • the precision of the gas spring provided by the utility model is greater than that of the screw rod, which can increase the stability of the lifting table, thereby making the lifting more stable, and solving the situation of shaking and leaning forward during the lifting process.
  • the spring force of the gas spring provided by the utility model is greater than or equal to the weight of the table body, so that the lifting screw can work under low load or no load, and the service life of the screw rod can be increased.
  • the gas spring force set by the utility model is greater than or equal to the weight of the table body, so that the DC motor for lifting and lowering can work under low load, which can increase the service life of the DC motor and reduce the energy of the DC motor.
  • Figure 1 is a schematic view of the overall structure of the present invention
  • Figure 2 is a front elevational view of the lifting device of the present invention
  • Figure 3 is a side view of the lifting device of the present invention.
  • Figure 4 is a front view of the utility model
  • Figure 5 is a side view of the present invention.
  • Figure 6 is a plan view of the present invention.
  • a new type of lifting table includes a table body 1 and a supporting mechanism 2, the inside of the table body 1 is a hollow structure, and the table body 1 is provided with a DC motor box 3 and a DC motor 4
  • the DC motor 4 is fixedly mounted inside the DC motor box 3;
  • the DC motor box 3 is provided with a through hole 5 near the lower bottom surface of the frame body 1 side;
  • the DC motor box 3 is provided with a transmission short shaft 6, the transmission short shaft 6 and The rotating shaft end of the DC motor 4 is connected;
  • the supporting mechanism 2 is provided with a lifting device 7, a cross bar 8 and a base 9;
  • the lifting bar 7 is mounted on both ends of the cross bar 8 , and the cross bar 8 is fixedly connected with the lifting device 7;
  • the sleeve assembly 10, the screw assembly 11 and the gas spring assembly 12 are composed;
  • the sleeve assembly 10 is provided with an inner sleeve 13, an outer sleeve 14, an inner sleeve plug 15 and an outer s
  • the rod 18 and the screw sleeve 19, the gas spring assembly 12 is provided with a gas spring 20 and a gas spring sleeve 21; the upper end of the screw rod 18 and the upper end of the gas spring 20 are fixedly connected with the transmission short shaft 6, and the lower end of the screw rod 18 is sleeved Inside the screw sleeve 19, the outer diameter of the lower end of the screw rod 18 matches the inner diameter of the screw sleeve 19, so that the screw rod 18 can slide freely inside the screw sleeve 19; the lower end of the gas spring 20 is sleeved at The inside of the gas spring sleeve 21, the outer diameter of the lower end of the gas spring 20 is matched with the inner diameter of the gas spring sleeve 21, so that the gas spring 20 can slide freely inside the gas spring sleeve 21; the base 9 is fixedly mounted by the fixed iron piece 17 The lower portion of the outer sleeve 14 is provided with two fixing screws 22 on the base 9.
  • the utility model increases the utility by providing the sleeve assembly 10, the screw assembly 11 and the gas spring assembly 12
  • the spring force of the gas spring 20 is greater than or equal to the weight of the table body 1, the screw 18 can be operated under low load or no load, and the service life of the screw rod 18 can be increased; the spring force of the gas spring 20 is greater than or equal to the weight of the table top.
  • the DC motor 4 for lifting and lowering can be operated under a low load, which can increase the service life of the DC motor 4 and reduce the energy of the DC motor 4.
  • the utility model provides a novel lifting table with simple structure, stable lifting and low energy consumption, which solves the problem that the lifting table is often unbalanced during the lifting process, and the plastic pipe plug wears with the inner casing after a certain period of time. If the gap is too large, the table will be shaken or tilted forward; the lifting screw will work under high load for a long time, which will shorten the service life of the screw; the DC motor for lifting and lowering will work under high load for a long time, which reduces the motor's The service life increases the problem of the ability of the motor.

Landscapes

  • Tables And Desks Characterized By Structural Shape (AREA)
  • Transmission Devices (AREA)

Abstract

一种新型升降桌,包括桌体(1)和支撑机构(2),桌体(1)设置有直流电机盒(3)和直流电机(4);直流电机(4)固定安装在直流电机盒(3)的内部;直流电机盒(3)设置有传动短轴(6),传动短轴(6)与直流电机(4)的转轴端连接;支撑机构(2)设置有升降装置(7)、横杆(8)和底座(9);横杆(8)两端均安装有升降装置(7);升降装置由套管组件(10)、丝杆组件(11)和气弹簧组件(12)组成;内套管(13)上端套接在直流电机盒(3)下底面开设的通孔(5)上;外套管(14)上端套接在内套管(13)下端,外套管(14)下端设置有固定铁片(17);丝杆组件(11)与气弹簧组件(12)同步平行安装在套管组件(10)的内部;底座(9)通过固定铁片(17)固定安装在外套管(14)下部;该新型升降桌,桌体可以自由升降,可根据实际情况调整高度,结构简单、升降平稳、能耗低。

Description

一种新型升降桌 技术领域
本实用新型涉及家具技术领域,尤其是一种新型升降桌。
背景技术
由人类的进化过程经历了四肢行走到直立行走,经过研究学者对世界家具的发展史的考察发现:人类直立行走后在日常活动中发现坐下有利于减轻疲劳,从而发明了坐具。这种坐着工作的方式随之传承下来,但随着人们坐着办公的时间越来越长,人们逐渐意识到久坐反而不利于工作效率的提高,人们开始尝试坐站交替式办公,渐渐的升降桌也就出现了,使用升降桌站式办公成为一种流行的健康办公方式。
自动升降桌一般是以电为动力来源,通过电动机控制机械装置来调节升降桌的高低,市面上现有的升降桌在升降过程中常常会不平衡,使用一定时长后随着内外套塑胶管塞磨损间隙过大造成桌子摇晃或前倾的情况;升降丝杆长期处于高负载的情况下工作,导致丝杆的使用寿命减短;升降用直流电机长期处于高负荷的情况下工作,降低了电机的使用寿命并增加了电机的能枆。
实用新型内容
本实用新型的目的在于提供一种结构简单、升降平稳、能耗低的新型升降桌,以解决上述背景技术中提出的问题。
为实现上述目的,本实用新型提供如下技术方案:一种新型升降桌,包括桌体和支撑机构,所述桌体内部为空心结构,桌体设置有直流电机盒和直流电机;所述直流电机固定安装在直流电机盒的内部;直流电机盒靠近桌体边框一侧的下底面开设有通孔;所述直流电机盒设置有传动短轴,传动短轴与直流电机的转轴端连接;所述支撑机构设置有升降装置、横杆和底座;所述横杆两端均安装有升降装置,横杆与升降装置固定连接;所述升降装置由套管组件、丝杆组件和气弹簧组件组成;所述套管组件设置有内套管、外套管、内套管塞和外套管塞;所述内套管上端套接在直流电机盒下底面开设的通孔上,内套管下端设置有内套管塞;所述外套管上端套接在内套管下端,外套管上端设置有外套管塞,外套 管下端设置有固定铁片;所述丝杆组件与气弹簧组件同步平行安装在套管组件的内部,丝杆组件设置有丝杆和丝杆套管,气弹簧组件设置有气弹簧和气弹簧套管;所述丝杆的上端和气弹簧的上端均与传动短轴固定连接,丝杆的下端套接在丝杆套管的内部,气弹簧的下端套接在气弹簧套管的内部;所述底座通过固定铁片固定安装在外套管下部,底座上设置有两个固定螺丝。
作为本实用新型进一步的方案:所述直流电机盒下底面开设的通孔尺寸与内套管的上端尺寸相匹配。
作为本实用新型进一步的方案:所述丝杆下端的外径与丝杆套管内径相匹配。
作为本实用新型进一步的方案:所述气弹簧下端的外径与气弹簧套管内径相匹配。
与现有技术相比,本实用新型有益效果:
1.本实用新型设置的气弹簧精密度大于丝杆,可增加升降桌的稳固性,从而升降更平稳,解决了升降过程中摇晃、前倾的情况。
2.本实用新型设置的气弹簧弹力大于或等于桌体的重量,可使升降的丝杆处于低负载或空载的情况下工作,可增加丝杆的使用寿命。
3.本实用新型设置的气弹簧弹力大于或等于桌体的重量,可使升降用的直流电机处于低负荷的情况下工作,可增加直流电机的使用寿命并降低直流电机的能枆。
附图说明
图1为本实用新型的整体结构示意图;
图2为本实用新型的升降装置主视图;
图3为本实用新型的升降装置侧视图;
图4为本实用新型的主视图;
图5为本实用新型的侧视图;
图6为本实用新型的俯视图。
图中:1-桌体;2-支撑机构;3-直流电机盒;4-直流电机;5-通孔;6-传动短轴;7-升降装置;8-横杆;9-底座;10-套管组件;11-丝杆组件;12-气弹簧组件;13-内套管;14- 外套管;15-内套管塞;16-外套管塞;17-固定铁片;18-丝杆;19-丝杆套管;20-气弹簧;21-气弹簧套管;22-固定螺丝。
具体实施方式
下面将结合本实用新型实施例中的附图,对本实用新型实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例仅仅是本实用新型一部分实施例,而不是全部的实施例。基于本实用新型中的实施例,本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例,都属于本实用新型保护的范围。
请参阅图1-6,本实用新型实施例中,一种新型升降桌,包括桌体1和支撑机构2,桌体1内部为空心结构,桌体1设置有直流电机盒3和直流电机4;直流电机4固定安装在直流电机盒3的内部;直流电机盒3靠近桌体1边框一侧的下底面开设有通孔5;直流电机盒3设置有传动短轴6,传动短轴6与直流电机4的转轴端连接;支撑机构2设置有升降装置7、横杆8和底座9;横杆8两端均安装有升降装置7,横杆8与升降装置7固定连接;升降装置7由套管组件10、丝杆组件11和气弹簧组件12组成;套管组件10设置有内套管13、外套管14、内套管塞15和外套管塞16;内套管13上端套接在直流电机盒3下底面开设的通孔5上,直流电机盒3下底面开设的通孔5尺寸与内套管13的上端尺寸相匹配,这样内套管13才能在内通孔5内自由滑动,套管13下端设置有内套管塞15;外套管14上端套接在内套管13下端,外套管14上端设置有外套管塞16,外套管14下端设置有固定铁片17;丝杆组件11与气弹簧组件12同步平行安装在套管组件10的内部,丝杆组件11设置有丝杆18和丝杆套管19,气弹簧组件12设置有气弹簧20和气弹簧套管21;丝杆18的上端和气弹簧20的上端均与传动短轴6固定连接,丝杆18的下端套接在丝杆套管19的内部,丝杆18下端的外径与丝杆套管19内径相匹配,从而丝杆18能在丝杆套管19的内部自由滑动;气弹簧20的下端套接在气弹簧套管21的内部,气弹簧20下端的外径与气弹簧套管21内径相匹配,从而气弹簧20能在气弹簧套管21内部自由滑动;底座9通过固定铁片17固定安装在外套管14下部,底座9上设置有两个固定螺丝22。
本实用新型,通过设置的套管组件10、丝杆组件11和气弹簧组件12,增加了本实用 新型的稳固性;气弹簧20与丝杆18两根支柱一起支撑升降,能有效解决只有丝杆18支撑升降使用一定时长后随着内外套塑胶管塞磨损间隙过大造成桌子摇晃或前倾的情况;气弹簧20弹力大于或等于桌体1的重量,可使丝杆18处于低负载或空载的情况下工作,可增加丝杆18的使用寿命;气弹簧20弹力大于或等于桌面的重量,可使升降用的直流电机4处于低负荷的情况下工作,可增加直流电机4的使用寿命并降低直流电机4的能枆。
综上所述,本实用新型提供一种结构简单、升降平稳、能耗低的新型升降桌,解决了升降桌在升降过程中常常会不平衡,使用一定时长后随着内外套塑胶管塞磨损间隙过大造成桌子摇晃或前倾的情况;升降丝杆长期处于高负载的情况下工作,导致丝杆的使用寿命减短;升降用直流电机长期处于高负荷的情况下工作,降低了电机的使用寿命并增加了电机的能枆的问题。
对于本领域技术人员而言,显然本实用新型不限于上述示范性实施例的细节,而且在不背离本实用新型的精神或基本特征的情况下,能够以其他的具体形式实现本实用新型。因此,无论从哪一点来看,均应将实施例看作是示范性的,而且是非限制性的,本实用新型的范围由所附权利要求而不是上述说明限定,因此旨在将落在权利要求的等同要件的含义和范围内的所有变化囊括在本实用新型内。不应将权利要求中的任何附图标记视为限制所涉及的权利要求。
此外,应当理解,虽然本说明书按照实施方式加以描述,但并非每个实施方式仅包含一个独立的技术方案,说明书的这种叙述方式仅仅是为清楚起见,本领域技术人员应当将说明书作为一个整体,各实施例中的技术方案也可以经适当组合,形成本领域技术人员可以理解的其他实施方式。

Claims (4)

  1. 一种新型升降桌,包括桌体(1)和支撑机构(2),其特征在于:所述桌体(1)内部为空心结构,桌体(1)设置有直流电机盒(3)和直流电机(4);所述直流电机(4)固定安装在直流电机盒(3)的内部;直流电机盒(3)靠近桌体(1)边框一侧的下底面开设有通孔(5);所述直流电机盒(3)设置有传动短轴(6),传动短轴(6)与直流电机(4)的转轴端连接;所述支撑机构(2)设置有升降装置(7)、横杆(8)和底座(9);所述横杆(8)两端均安装有升降装置(7),横杆(8)与升降装置(7)固定连接;所述升降装置(7)由套管组件(10)、丝杆组件(11)和气弹簧组件(12)组成;所述套管组件(10)设置有内套管(13)、外套管(14)、内套管塞(15)和外套管塞(16);所述内套管(13)上端套接在直流电机盒(3)下底面开设的通孔(5)上,内套管(13)下端设置有内套管塞(15);所述外套管(14)上端套接在内套管(13)下端,外套管(14)上端设置有外套管塞(16),外套管(14)下端设置有固定铁片(17);所述丝杆组件(11)与气弹簧组件(12)同步平行安装在套管组件(10)的内部,丝杆组件(11)设置有丝杆(18)和丝杆套管(19),气弹簧组件(12)设置有气弹簧(20)和气弹簧套管(21);所述丝杆(18)的上端和气弹簧(20)的上端均与传动短轴(6)固定连接,丝杆(18)的下端套接在丝杆套管(19)的内部,气弹簧(20)的下端套接在气弹簧套管(21)的内部;所述底座(9)通过固定铁片(17)固定安装在外套管(14)下部,底座(9)上设置有两个固定螺丝(22)。
  2. 根据权利要求1所述的一种新型升降桌,其特征在于:所述直流电机盒(3)下底面开设的通孔(5)尺寸与内套管(13)的上端尺寸相匹配。
  3. 根据权利要求1所述的一种新型升降桌,其特征在于:所述丝杆(18)下端的外径与丝杆套管(19)内径相匹配。
  4. 根据权利要求1所述的一种新型升降桌,其特征在于:所述气弹簧(20)下端的外径与气弹簧套管(21)内径相匹配。
PCT/CN2017/101350 2016-10-26 2017-09-12 一种新型升降桌 WO2018076943A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201621192771.6U CN206413974U (zh) 2016-10-26 2016-10-26 一种新型升降桌
CN201621192771.6 2016-10-26

Publications (1)

Publication Number Publication Date
WO2018076943A1 true WO2018076943A1 (zh) 2018-05-03

Family

ID=59578756

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2017/101350 WO2018076943A1 (zh) 2016-10-26 2017-09-12 一种新型升降桌

Country Status (2)

Country Link
CN (1) CN206413974U (zh)
WO (1) WO2018076943A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112869345A (zh) * 2021-01-22 2021-06-01 王林 一种方便清理的办公桌

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN206413974U (zh) * 2016-10-26 2017-08-18 成武 一种新型升降桌
CN107772790B (zh) * 2017-11-17 2023-06-16 湖南妙能电器有限公司 一种可拆卸升降桌脚
CN108040823A (zh) * 2017-12-10 2018-05-18 巫溪县薯光农业科技开发有限公司 一种冷库变温催芽用供水浇灌装置
CN108371397A (zh) * 2018-04-11 2018-08-07 苏州根特工业设备有限公司 气动弹簧双腿同步升降桌

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5775234A (en) * 1995-10-12 1998-07-07 Bissell Inc. Height adjustable overbed table and locking device therefor
CN2363566Y (zh) * 1999-04-08 2000-02-16 侯祖杰 桌椅高度调节器
CN2538204Y (zh) * 2002-05-20 2003-03-05 赖方滉 可调整高度的升降桌
CN2634909Y (zh) * 2003-08-13 2004-08-25 陈顺杭 高度可升降的桌椅
CN200994547Y (zh) * 2007-01-12 2007-12-26 上海市闵行第二中学 一种新型升降桌
CN201426495Y (zh) * 2009-05-19 2010-03-24 郭耀辉 一种电动升降桌
CN204840126U (zh) * 2015-06-17 2015-12-09 郭艾芳 一种用于医疗手术台的柔性升降装置
CN206413974U (zh) * 2016-10-26 2017-08-18 成武 一种新型升降桌

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5775234A (en) * 1995-10-12 1998-07-07 Bissell Inc. Height adjustable overbed table and locking device therefor
CN2363566Y (zh) * 1999-04-08 2000-02-16 侯祖杰 桌椅高度调节器
CN2538204Y (zh) * 2002-05-20 2003-03-05 赖方滉 可调整高度的升降桌
CN2634909Y (zh) * 2003-08-13 2004-08-25 陈顺杭 高度可升降的桌椅
CN200994547Y (zh) * 2007-01-12 2007-12-26 上海市闵行第二中学 一种新型升降桌
CN201426495Y (zh) * 2009-05-19 2010-03-24 郭耀辉 一种电动升降桌
CN204840126U (zh) * 2015-06-17 2015-12-09 郭艾芳 一种用于医疗手术台的柔性升降装置
CN206413974U (zh) * 2016-10-26 2017-08-18 成武 一种新型升降桌

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112869345A (zh) * 2021-01-22 2021-06-01 王林 一种方便清理的办公桌

Also Published As

Publication number Publication date
CN206413974U (zh) 2017-08-18

Similar Documents

Publication Publication Date Title
WO2018076943A1 (zh) 一种新型升降桌
CN203388541U (zh) 一种调节式自动起身休闲躺椅
CN206443395U (zh) 可升降节省空间的桌子
CN205709753U (zh) 一种景观设计升降台
CN204763796U (zh) 一种多功能旅行拐杖
CN206904693U (zh) 一种室内设计用落地灯具
CN206079777U (zh) 一种木质伸缩凳
CN201277521Y (zh) 能够任意调节高度的吊灯
CN204783752U (zh) 可伸缩的小风扇
CN201368304Y (zh) 一种笔记本万向支架
CN203506093U (zh) 便携可拆式板凳
CN208011379U (zh) 一种可调节光照角度的led台灯
CN208447016U (zh) 一种腰部按摩椅子
CN202560596U (zh) 壁挂式两用风扇
CN204783753U (zh) 可升降的小风扇
CN205947482U (zh) 一种便携可折叠式户外餐桌
CN204636767U (zh) 一种简易助行椅
CN203468054U (zh) 转椅
CN205041019U (zh) 一种沙发骨架
CN214428000U (zh) 一种电力营销自助式服务设备
CN205197507U (zh) 基于滑轮结构的弹簧式桌椅移动装置
CN201057889Y (zh) 一种方便座椅
CN206151359U (zh) 一种肢体障碍人士用坐便器扶手
CN208784096U (zh) 一种竹竿圆筒凳
CN210227292U (zh) 一种简易家用升降装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17864790

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17864790

Country of ref document: EP

Kind code of ref document: A1