1、BRITISH STANDARD BS1937:1953 Specification for Engineers ratchet braces and drilling pillarsBS1937:1953 This BritishStandard, having been approved by the MechanicalEngineering IndustryStandards Committeeand endorsed bytheChairman of the Engineering Divisional Council,was published undertheauthority
2、of theGeneralCouncil on 10February1953 BSI12-1999 MEE/120 ISBN 0 580 359875 Co-operating organizations The Mechanical Engineering Industry Standards Committee, under whose supervision this BritishStandard was prepared, consists of representatives from the following Government departments and scienti
3、fic and industrial organizations: Admiralty* Institute of Petroleum Air Ministry Institution of Civil Engineers Associated Offices Technical Committee Institution of Gas Engineers Association of Consulting Engineers Institution of Heating and Ventilating (Incorporated) Engineers British Chemical Pla
4、nt Manufacturers Institution of Mechanical Engineers Association Institution of Mechanical Engineers British Compressed Air Society (Automobile Division) British Electrical and Allied Manufacturers Institution of Production Engineers* Association Locomotive Manufacturers Association* British Electri
5、city Authority and Area Boards Machine Tool Trades Association British Engineers Association* Ministry of Fuel and Power British Internal Combustion Engine Ministry of Labour and National Service Manufacturers Association (Factory Department) British Iron and Steel Federation Ministry of Supply* Bri
6、tish Railways, The Railway Executive* Ministry of Transport* Crown Agents for the Colonies Ministry of Works D.S.I.R. Mechanical Engineering Research National Physical Laboratory Organization Office of the High Commissioner for India Engineering Equipment Users Association* War Office Institute of M
7、arine Engineers The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this BritishStandard: Association of U.K. Plier Manufacturers In
8、stitution of Engineering Inspection Edge Tool Manufacturers Association London Transport Executive Engineers and Allied Hand Tool Makers National Association of Tool Dealers Association National Coal Board Federation of British Hand Tool Manufacturers Saw Trades Association Gas Council Society of Br
9、itish Aircraft Constructors General Post Office Society of Motor Manufacturers and J.E.S.C. Sub-Committee on Hand Tools Traders Ltd. Light Edge Tool and Allied Trades Association Co-opted manufacturers Amendments issued since publication Amd. No. Date CommentsBS1937:1953 BSI 12-1999 i Contents Page
10、Co-operating organizations Inside front cover Foreword ii Section 1. General 1 Scope 1 2 Nomenclature and definitions 1 Section 2. Ratchet bracesmanufacture 3 Materials 4 4 Heat treatment and hardness 4 5 Finish 4 6 Assembly 4 7 Capacity and dimensions 4 Section 3. Drilling pillarsmanufacture 8 Mate
11、rials 13 9 Locking eyebolt and key 13 10 Base 13 11 Dimensions 13 Appendix Adaptors 16 Figure 1 Long head (box) type 2 Figure 2 Short head type 3 Figure 3 Extra short head type (pin brace) 3 Figure 4 Short head heavy duty type (boiler brace) 3 Figure 5 Bit stock type 4 Figure 6 Exploded view of the
12、component parts of enclosed ratchet type of brace 9 Figure 7 Exploded view of the component parts of open ratchet type of brace 10 Figure 8 Nozzle and box for long head (box) type 11 Figure 9 Exploded view of the component parts of short head heavy duty type brace 12 Figure 10 Drilling pillar 15 Fig
13、ure 11 Adaptor 16 Table 1 Long head (box) brace for square taper shank drills 5 Table 2 Long head (box) brace for Morse taper shank drills 6 Table 3 Short head brace 6 Table 4 Extra short head bracepin brace 7 Table 5 Short head, heavy dutyboiler brace 8 Table 6 Bit stock brace 8 Table 7 Drilling pi
14、llars 14 Table 8 Adaptors for converting ratchet braces from Morse taper to square taper 16BS1937:1953 ii BSI 12-1999 Foreword This standard makes reference to the following British Standards: BS 51, Wrought iron for general engineering purposes (grades A, B and C). BS 328, Twist drills and combined
15、 drills and countersinks (centre drills). BS 427, Tables of diamond pyramid hardness numbers. BS 970, Wrought steels. This BritishStandard has been prepared under the authority of the Mechanical Engineering Industry Standards Committee and forms one of a series relating to hand tools. The various ty
16、pes of brace and the component parts are defined and the clauses specify requirements for the materials, heat treatment and hardness, finish and assembly of the tools. A series of tables gives a range of dimensions for the ratchet braces, the range being extended to include the dimensional requireme
17、nts of drilling pillars, in view of the need to ensure that the correct brace and pillar are associated in some applications. While the drilling pillar dimensions have thus been associated with the range of ratchet braces, they have also been correlated with the drill lengths given in BS328 1) The s
18、tandard is intended to apply only to the most commonly used types of tool and pillar; certain types, particularly of drilling pillar, although popular in certain branches of industry, are considered to be special to those branches and have therefore been omitted. The conversion of nozzles from Morse
19、 taper to square taper is effected by adaptors, the range of which is given in the Appendix. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does no
20、t of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to16, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will
21、 be indicated in the amendment table on the inside front cover. 1) BS328, “Twist drills and combined drills and countersinks (centre drills).”BS1937:1953 BSI 12-1999 1 Section 1. General 1 Scope This BritishStandard specifies requirements for engineers ratchet braces and drilling pillars. The ratche
22、t braces are of the following types: a) Long head (box) type, having an open or totally enclosed ratchet and available with either i) Square taper nozzle, or ii) Morse taper nozzle. b) Short head type, having an open or totally enclosed ratchet. Suitable for square taper shank drills only. c) Extra
23、short head type (pin brace), having an open or totally enclosed ratchet. Suitable for square taper shank drills only. d) Short head type heavy duty (boiler brace), having totally enclosed ratchet, available with square taper nozzle. e) Bit stock type, having an open or totally enclosed ratchet. Suit
24、able for bit stock drills only. Nomenclature and definitions are given, together with requirements for materials, heat treatment, hardness, finish and accuracy of assembly. Ranges of dimensions of the various types of brace and of the drilling pillars are also included. 2 Nomenclature and definition
25、s 2.1 Types of brace 2.1.1 engineers ratchet brace a hand tool designed for rotating drills, reamers or similar small tools having Morse taper or square taper shanks a reciprocating handle actuates the cutting tool through a pawl and toothed wheel, while an adjustable screwed member having a jack ac
26、tion provides the feed into the work 2.1.2 long head (box) type the type suitable for general purposes, for use where the working space is not limited. The feed is designed for application by spanner, but can also be applied by hand. (See Figure 1) 2.1.3 short head type for use where space is limite
27、d. The feed is designed for application by tommy bar. (See Figure 2) 2.1.4 extra short head type (pin brace) for use in more confined spaces than those for which the short head type is intended. (See Figure 3) 2.1.5 short head type heavy duty (boiler brace) a short head type of much more robust cons
28、truction than the types defined in2.1.3 and2.1.4, and designed for use on boiler plates and pressure vessels or similar heavy material. (See Figure 4) 2.1.6 bit stock type a light design intended solely for use with bit stock drills. (See Figure 5) 2.2 Component parts 2.2.1 frame the housing for the
29、 nozzle and rack integral with the handle. (See Figure 6, Figure 7 and Figure 9) 2.2.2 nozzle the member which accommodates the drill; it is designed to support and be turned by the rack, and incorporates the means for applying the feed. (SeeFigure 6, Figure 7, Figure 8 and Figure 9) 2.2.3 rack the
30、circular toothed member, actuated by the pawl through which the torque is applied. (See Figure 6, Figure 7, Figure 8 and Figure 9) 2.2.4 pawl the member controlling the rack. (See Figure 6, Figure 7 and Figure 9) 2.2.5 spring the member through which the pressure is applied to the pawl. (See Figure
31、6, Figure 7 and Figure 9) 2.2.6 screw centre a centering device having an external thread through which the feed is applied on the short head or pin type. (See Figure 6, Figure 7 and Figure 9) 2.2.7 box the hexagon member carrying the centering device, having an internal thread. Used on the long hea
32、d type. (See Figure 8)BS1937:1953 2 BSI 12-1999 Figure 1 Long head (box) typeBS1937:1953 BSI 12-1999 3 Figure 2 Short head type Figure 3 Extra short head type (pin brace) Figure 4 Short head heavy duty type (boiler brace)BS1937:1953 4 BSI 12-1999 Section 2. Ratchet braces manufacture 3 Materials The
33、 various components of the ratchet braces to which this BritishStandard relates shall be manufactured from the materials specified below: a) Frame, nozzle and box. Mild steel, such as EN1A specified in BS970. 2) b) Screw centre and rack. Mild steel suitable for case-hardening, such as EN32A or EN32M
34、 specified in BS970. c) The apices of the screw centre and the box. An insert of steel having a carbon content of not less than0.85percent and not more than0.95percent. d) Pawl. Steel having a carbon content of not less than0.85percent and not more than0.95percent. NOTESteels having equivalent physi
35、cal properties may be used as an alternative to any of those specified in a, b, c or d above. 4 Heat treatment and hardness a) Screw centre and rack. The screw centre and the rack shall be case-hardened to produce a depth of case not less than0.010in. The hardness of the case shall be within the ran
36、ge400/550 on the diamond pyramid scale. 3)During the hardness check the load applied shall not exceed10Kg. b) Pawl and the apices of screw centre and box. The pawls, the apex of the screw centre and the apex of the box shall be hardened to a hardness reading within the range400/500 on the diamond py
37、ramid scale, with a load of10Kg. 5 Finish The complete ratchet braces and the component parts shall be of smooth and neat finish with all burrs and sharp corners removed. They shall also be free from surface defects and cracks. 6 Assembly The dimensional accuracy of all component parts and details s
38、hall be such that the resultant assembly shall function efficiently and shall, in addition, ensure that any components which can be detached during use shall be interchangeable. NOTEWhere vee threads are specified in the tables of dimensions, free fits have been given, but it has not been possible t
39、o specify tolerances for the square threads because of the absence of a BritishStandard for such threads. 7 Capacity and dimensions The normal capacity of the ratchet braces and the dimensions necessary to ensure interchangeability shall be those given in Table 1 to Table 6 inclusive. NOTECentres A
40、and B are interchangeable (see Table 6). Figure 5 Bit stock type 2) BS970, “Wrought steels.” 3) BS427, “Tables of diamond pyramid hardness numbers.”BS 1937:1953 BSI 12-1999 5 Table 1 Long head (box) brace for square taper shank drills All dimensions are in inches 1 2 3 4 5 6 7 8 Nominal length, cent
41、re line of head to end of handle Dimension across head in closed position Length of screw, including shoulder Diameter of screw, square thread Pitch of screw Number of teeth in rack Hexagon across flats dimension of box Type of shank for which nozzle is designed L (Figure 1) M (Figure 1) S (Figure 8
42、) D (Figure 8) Maximum t.p.i. 10 6 2 1 / 4 13 / 16 6 15 1.250 No.2square taper 12 7 1 / 8 2 3 / 4 7 / 8 6 15 1.250 No.2square taper 14 8 3 3 / 8 1 6 15 1.437 No.2square taper 16 8 5 / 8 3 3 / 4 1 1 / 8 6 15 1.437 No.2square taper 18 9 1 / 8 4 1 / 4 1 1 / 8 6 15 1.437 No.2square taper 20 9 3 / 4 4 1
43、/ 4 1 1 / 8 6 15 1.625 No.2square taper 22 10 1 / 2 4 1 / 4 1 1 / 8 6 15 1.625 No.2square taper 24 11 1 / 2 4 1 / 4 1 1 / 8 6 15 1.625 No.2square taperBS 1937:1953 6 BSI 12-1999 Table 2 Long head (box) brace for Morse taper shank drills Table 3 Short head brace All dimensions are in inches 1 2 3 4 5
44、 6 7 8 Nominal length, centre line of head to end of handle Dimension across head in closed position Length of screw including shoulder Diameter of screw, square thread Pitch of screw Number of teeth in rack Hexagon across flats dimension of box Type of shank for which nozzle is designed L (Figure 1
45、) M (Figure 1) S (Figure 8) D (Figure 8) Maximum t.p.i. 12 15 18 24 6 6! 7“ 12! 2# 2# 3“ 7# = 4“ screw 3! plain + 1( 1) 1! (Plain part1“) 6 6 6 6 15 15 15 15 1.250 1.437 1.625 1.625 No.1Morse taper No.2Morse taper No.3Morse taper No.4Morse taper All dimensions are in inches 1 2 3 4 5 6 7 8 Nominal l
46、ength, centre line of head to end of handle Dimension across head in closed position Length of screw Diameter of screw, square thread Pitch of screw Number of teeth in rack Type of shank for which nozzle is designed Diameter of clearing hole for tommy bar L (Figure 2) M (Figure 2) t.p.i. 10 4 2 5 /
47、8 6 15 No.2square taper 11 / 32 12 4 1 / 2 2 5 / 8 6 15 No.2square taper 11 / 32 14 5 1 / 4 2 1 / 4 3 / 4 6 15 No.2square taper 11 / 32 16 5 3 / 4 2 3 / 4 7 / 8 6 15 No.2square taper 13 / 32 18 6 1 / 4 2 3 / 4 7 / 8 6 15 No.2square taper 13 / 32 20 6 3 / 4 2 3 / 4 7 / 8 6 15 No.2square taper 13 / 32
48、 22 7 2 3 / 4 7 / 8 6 15 No.2square taper 13 / 32 24 7 1 / 2 2 3 / 4 7 / 8 6 15 No.2square taper 13 / 32BS 1937:1953 BSI 12-1999 7 Table 4 Extra short head bracepin brace All dimensions are in inches 1 2 3 4 5 6 7 8 Nominal length from centre line of head to end of handle Dimension across head in cl
49、osed position Length of screw Diameter of screw, square thread Pitch of screw Number of teeth in rack Type of shank for which nozzle is designed Diameter of clearing hole for tommy bar L (Figure 3) M (Figure 3) t.p.i. 10 2 1 / 2 1 9 / 16 8 15 No.2square taper (No.1square taper supplied at customers option) 9 / 32 12 3 1 1 / 2 5 / 8 6 15 No.2square taper (No.1square taper supplied at customers option) 11 / 32 14 3 1 / 2 1 1 / 2 5 / 8 6 15 No.2square taper (No.1square taper supplied at custome
