Electrical Contact Terminal And Connector

Abstract

Hermaphroditic electrical terminal comprises web having sidewalls extending from the longitudinal edges thereof. Means extend from one end of the web for securing the terminal to a conductor and contact springs are provided at the other end of the terminal. These contact springs comprise planar extensions of the sidewalls which project forwardly and are reversely bent inwardly and towards the rearward end of the terminal in converging relationship to the axis thereof. Two electrical terminals of this type can be mated with each other by positioning them in opposed inverted relationship and moving them together so that one contact spring and one sidewall of each terminal are received between the contact springs of the other terminal. Terminals disclosed can also receive other electrical contact terminals of types that are commonly used on the present day computer and peripheral computer equipment. A connector housing is also disclosed having cavities which are adapted to receive electrical terminals in accordance with the invention.

Description

BACKGROUND OF THE INVENTION

This invention relates to electrical connectors and electrical contact terminals which are hermaphroditic and which are also capable of being mated with dissimilar terminals and connectors. The invention is herein disclosed in an embodiment particularly intended for use with present day computers and peripheral computer equipment although connectors and terminals in accordance with the invention can be used in other types of equipment to advantage. In the description which follows, the disclosed embodiment is particularly described with reference to its intended use in computer and peripheral computer equipment.

A typical computer installation of the type which might be used by business, industry, or government comprises a central processor unit (CPU) and selected peripheral equipment in the form of a tape drive, a tape drive controller, or a disk drive and disk drive controller, and additional equipment such as a key punch verifier. There are at present several manufacturers of central processor units who also manufacture the required peripheral equipment and there are additional manufacturers who produce only the peripheral equipment for the central processor unit. Quite often, an installation will be composed of a central processor unit from one manufacturer and will include peripheral equipment which may have been produced by two or three other manufacturers.

All of the equipment which comprises the computer installation must be electrically interconnected by large numbers of conductors and multi-contact electrical connectors are commonly used to form these connections. The computer industry has, therefore, standardized to a large extent on a particular type of connector and contact terminal to permit electrical interfacing among and between the processor units and peripheral equipment of all manufacturers.

It has been recognized in the computer industry for several years that it would be advantageous if an additional type of electrical terminal were available for use in the industry for the various units which must be electrically interconnected. One requirement of such a connector would be that it be hermaphroditic so that if used with two different types of equipment produced by two different manufacturers, the two types of equipment could be electrically connected to each other. Another requirement which has been recognized is that a connector and terminal used on computer equipment must be capable of being mated with existing connectors on existing computer equipment. The instant invention is directed to the achievement of an improved electrical connector which will fulfill this need in the industry.

It is accordingly an object of the invention to provide an improved electrical contact terminal. It is a further object to provide a hermaphroditic contact terminal which is also capable of being mated with the dissimilar terminal. A further object is to provide a multi-contact electrical connector which is both hermaphroditic and which is capable of being mated with a similar connector having dissimilar contact terminals therein. It is a further object to provide a relatively low cost, high reliability electrical connector suitable for use with the computers and computer related equipment.

These and other objects of the invention are achieved in a preferred embodiment thereof which is briefly described in the foregoing abstract, which is described in detail below, and which is shown in the accompanying drawings in which:

FIGS. 1 and 2 show a pair of electrical connectors in accordance with the invention in alignment with each other and illustrating the manner in which they are engaged with each other.

FIG. 2A is a view taken along the lines 2--2 of FIG. 1.

FIG. 3 is a perspective view of the rearward side of one of the connectors of FIG. 1 with the strain relief plate exploded from the connector block.

FIG. 4 is a transverse sectional view of the pair of connectors in accordance with the invention illustrating the manner in which the contact terminals are mated with each other.

FIG. 5 is a fragmentary sectional perspective view showing one of the contact receiving cavities in the connector housing shown in FIGS. 1 and 2 and also showing a contact terminal in alignment with the cavity preparatory to insertion.

FIG. 6 is a perspective view of the cavity with parts broken away to reveal features of the internal structure thereof.

FIG. 7 is a sectional side view of the cavity shown in FIG. 6.

FIGS. 8 and 9 are views taken along the lines 8--8 and 9--9 of FIG. 7.

FIG. 10 is a sectional side view of the cavity of FIG. 5 having a contact terminal mounted therein.

FIG. 11 is a view taken along the lines 11--11 of FIG. 10.

FIG. 11A is a view taken along the lines 11A--11A of FIG. 4

FIG. 12 is a perspective view of a known type of electrical contact terminal which is commonly used on computers and peripheral equipment.

FIG. 13 is a fragmentary sectional side view of a portion of two connectors mated with each other, one of these connectors having contact terminals of the type shown in FIG. 12 therein and the other connector having contact terminals in accordance with the instant invention therein.

FIG. 14 is a view taken along the lines 14--14 of FIG. 13.

FIG. 15 is a sectional side view of a contact terminal in accordance with the invention mated with a conventional contact blade.

FIG. 16 is a perspective view, similar to FIG. 3, of an alternative form of cable clamp in accordance with the invention.

Referring first to FIGS. 1, 2 and 5, a preferred form of electrical contact terminal 2 in accordance with the invention is adapted to be crimped onto a wire 18 and inserted into a contact receiving cavity 4 in a connector housing 6. The terminal 2 and the housing 4 is hermaphroditic, as will be described below, so that they can be engaged with an identical terminal and housing although terminals and housings in accordance with the invention can also be mated with similar housings having dissimilar terminals therein.

Each terminal 2 has a central U-shaped section comprising a web 8 and upstanding sidewalls 10, 12 which extend laterally from the longitudinal edges of the web. A wire crimp portion 44 extends from the righthand end of the web 8, as viewed in FIG. 5 to secure the terminal to the insulating core of a wire or other conductor 18. Additionally, an insulation crimp 16 is provided in alignment with the wire crimp 14 to provide a strain relief for the wire crimp.

A pair of contact springs 20, 22 extend from the forward end of the sidewalls 10,12, each contact spring comprising a planar extension 24 of the sidewall from which it extends. Each spring is reversely bent forwardly of the central U-shaped section as shown at 26 so that the end portion 28 of the spring extends rearwardly between the sidewalls and obliquely towards the axis of the terminal. The opposed surfaces of these springs are thus tapered towards each other and will be resiliently flexed away from each other upon insertion of a mating terminal device. Advantageously, the end of the springs are curved outwardly as shown at 30 to prevent damage to the contact terminals in a complementary connector upon coupling and decoupling. It should be noted that the contact springs 20, 22 have a width which is less than the width of the sidewalls 10, 12 so that the sides of the springs are spaced from the lower ends and the upper edges of the sidewalls as is apparent from FIG. 5.

The lefthand end of the terminal as viewed in FIG. 5, the end defined by the bends 26, is regarded as the forward end and the righthand end on which the crimp portion 16 is provided is regarded as being the rearward end. The portions 28 of the springs thus extend rearwardly and obliquely with regard to the longitudinal axis of the terminal.

Suitable retention means are provided for retaining the contact terminal 2 in a cavity, which is described below, in the form of a lance 34 and a shoulder 32 on the sidewall 12. The lance 34 is struck inwardly from the web 8 and extends obliquely between the sidewalls 10, 12 and rearwardly towards the righthand end of the terminal. The shoulder 32 is formed by an ear on the rearward end of sidewall 12 and faces forwardly for engagement with a suitable shoulder in the contact cavity.

The electrical contact terminal 2 of FIG. 5 can be engaged with an identical terminal by positioning the two terminals in opposed inverted relationship with respect to each other and with their axes offset so that one contact spring and one sidewall of each terminal will be received between the two contact springs of the other terminal when the two terminals are moved towards each other as shown best in FIG. 4. Two mated terminals thus provide three separate areas of electrical contact each of which is maintained by at least one of the contact springs of the terminals. It has been found that a mated pair of electrical contact terminals in accordance with the invention will provide a stable low resistance electrical connection which is not disturbed by vibration or mechanical shock.

The phrase "opposed inverted relationship" as used in the foregoing paragraph is intended to mean that each terminal is inverted top to bottom with respect to the other terminal as viewed in FIG. 4. It follows that when two terminals in accordance with the invention are mated with each other, the webs 8 of the terminals are substantially co-planar.

Electrical terminals in accordance with the invention are advantageous in that they can be made in relatively small sizes from thin metal stock. The central channel section is structurally durable and functions to protect the contact surfaces of the end portions 28 of the contact springs. Furthermore, the springs themselves are sized or set when the terminal is inserted into a cavity housing as will be described below.

Referring now to FIGS. 4-9, each of the cavities 4 extends through the block 6 from the rearward face 36 thereof to the mating face 38. The rearward face of each connector has a transverse central rib 42 which divides the upper and lower rows of contact receiving cavities so that the cavities of each row open into a transverse trough as indicated at 40, FIG. 4. Each cavity can be divided, for purposes of description, into a rearward section 44 and a forward section 46 which opens onto the mating face 38 of the housing block. The rearward section of each cavity has top and bottom walls 48, 50 as viewed in FIG. 5 that are substantially smooth and uninterrupted. The sidewall 52, shown on the right in FIG. 9, is also substantially smooth and uninterrupted while the opposite sidewall 54 has grooves or slots 56,58 extending forwardly from the rearward side of the housing. The slot 56 has a width throughout its length which is substantially equal to, and slightly greater than, the thickness of the metal stock from which the contact terminal is formed so that the sidewall 12, of a terminal 2 can be received in this slot upon insertion of the terminal into the cavity. The lower slot 58, as viewed in FIG. 7, is relatively wide at its righthand end and has a narrower front portion 60 which has a width equal to, and slightly greater than, the metal stock thickness. This lower slot 60 ends in a rearwardly facing shoulder 62 (See FIG. 8) against which the forwardly facing shoulder 32 of a terminal is adapted to move in order to limit leftward movement of the terminal through the cavity. The central portion of the sidewall 54 is substantially flat and a ramp 64 extends from the central portion of the wall to the surface of the enlarged slot portion 58.

A boss 66 extends outwardly from the central portion of sidewall 54 towards the sidewall 52 and provides a forwardly facing surface 67 against which the edge of the retention lance 34 bears upon insertion of the terminal. It will be apparent from FIGS. 5 and 10 that the rearward portion of the cavity is thus dimensioned to receive the central U-shaped portion of the terminal 2 relatively snugly so that the contact springs will be precisely positioned in the forward portion thereof.

The sidewall 52 of the cavity extends towards the mating face through the enlarged frontal section of the cavity and the opposite sidewall 68 has a generally L-shaped flat surface which extends rearwardly to the previously identified shoulder 62, see FIGS. 7 and 8. A central inclined ramp 70 is provided on sidewall 68 which extends to the level of the sidewalls 54 of the rearward cavity portion. This ramp is provided for molding convenience and efficiency in part and to provide additional surface for the sidewall 10 for bearing at its forward end. The forward portion 46 of the cavity extends laterally beyond the plane of the cavity wall 48 as shown at 74 to permit mating of a terminal in a cavity with a terminal in a similar cavity in a connector in opposed inverted relationship as is apparent from FIG. 4. The side 68 of the forward portion of the cavity is beveled as shown at 76 and the upper surface of the cavity is rounded as shown at 78. The beveled surface 76 provides a guiding surface for a mating terminal when two connectors are engaged with each other.

Insertion of an individual terminal 2 into a contact receiving cavity 4 is accomplished by orienting the terminal as shown in FIG. 5 relative to the axis of the cavity and moving the terminal leftwardly until the shoulder 32 on the terminal moves against the shoulder 62 in the cavity and until the retention lance 34 snaps over the boss 66 so that its trailing edge is against the forwardly facing surface 67 of this boss. If the terminal is not properly oriented, it can not be inserted for the reason that the terminal sidewalls must enter the grooves 56,58.

As previously pointed out, the contact springs 20, 22 are more narrow than the sidewalls 10, 12 of the terminal and extends centrally from the forward ends of the sidewalls so that the sides of the springs are spaced from the web and from the outer edges of the sidewalls. This design is advantageous in that the leading ends of the springs on the terminals of one connector are not likely to engage the surface of the mating face of another connector when the two connectors are coupled as is apparent from FIG. 11. The reduced widths of these springs is also important for other reasons which are described below.

An advantage of the disclosed cavity and terminal is that the contact springs 20, 22 are sized or set during insertion as they are moved past the boss 66. For example, if the ends of these contact springs should be overly close to each other, the ends will be forced apart by boss 66 during insertion so that they will be properly spaced after insertion. This feature avoids the necessity of sizing or setting the springs when the connector is first mated with a complementary connector; setting or sizing of the springs during the first mating is undesirable for the reason that a high coupling force may be required (if the springs are overly close to each other) and damage to the contact terminals in the connector or the mating connector may result from the high coupling force.

The connector block has top and bottom walls as viewed in the drawings, 80, 82 and end walls, 84, 86. Mounting ears 88 extend laterally from the end walls and are provided with openings for mounting screws in the event that connectors should be mounted on a panel or other surface. A two section hood 90, 92 extends forwardly from the mating face in surrounding relationship to the cavities the hood sections 90, 92 being dimensioned such that two identical connectors in accordance with the invention can be mated with each other when they are in opposed inverted relationship, top to bottom, as explained above. Upon mating the two connectors, the hood section 90 of the one connector will move within and against the internal surface of the section 92 of the other connector.

The reduced widths of the springs permits mating of the connector blocks as explained above and as shown in FIG. 11A. It will be apparent from FIG. 11A that, on each terminal, these springs must be of reduced width in order to move past the channel-shaped section of the terminal in the complementary connector. The reduced widths are also of importance when a connector having contact terminals as shown in FIG. 12 contained in its cavities as will be explained below.

The center portion 94 of the block does not have contact receiving cavities therein but is rather provided with two circular openings 96, 98. The opening 96 has an enlarged forward end in which a threaded bushing 97 is mounted and the opening 98 has an enlarged rearward end which opens into the rearward side of the block. A conventional jack screw 95 extends through the opening 98 and is retained in position by a split ring washer 101 mounted on the jack screw adjacent to its forward end. A spring 99 is interposed between the head of the jack screw and the inner end of the enlarged portion of the hole 98. The threaded end of the jack screw has threads conforming to those of the bushing 97 so that connectors in accordance with the invention can be coupled to each other when they are positioned in opposed inverted relationship.

On the rearward side of the block, the sidewall 80 has a projecting flange 100 and the lower sidewall 82 as viewed in FIG. 4 has a projecting flange 102. The rearward ends of the terminals mounted in the cavities and the adjacent portions of the conductors are thus protected within these two flanges. The lower flange 102 on the sidewall 82 merges with a relatively thick section of this sidewall through an inclined surface 118 which cooperates with a strain relief described immediately below.

The disclosed form of strain relief, which clamps the conductors 18 against the housing, is in the form of a flat plate 104 having a flange 106 on one side thereof. A central notch 108 is provided on the side opposite to the flange for the accomodation of the jack screw as described above and openings are provided at each for fasteners 110. Additionally, a central square opening is punched in the plate 104 which is adapted to receive a boss 114 on the internal surface of the flange 100. The dimensions of the boss and the dimensions of the openings are such that the plate will loosely pivot with respect to the boss when it is positioned thereon. The clamping plate is assembled to the housing by locating the boss 114 in the hole 112, swinging the plate towards the housing so that the conductors are clamped against the rounded surface 118, inserting the screws 110 through the openings and threading the screws into bushings 111 provided in the corresponding corners of the housing.

As an alternative to the clamping plate mounting arrangement shown in FIG. 3, the clamping plate can be provided with ears 146 on the lefthand side as viewed in FIG. 16 which are adapted to extend into recesses 148 in the housing block to loosely pivot the clamping plate to the rearward end of the housing. As with the previously described embodiment, the clamping plate is secured to the housing by the fasteners 110.

The disclosed form of housing block is commonly used in the computer art as described above and is provided on numerous types of computer equipment, both central processor units and peripheral equipment. It follows that if connectors of the type shown in FIGS. 1 and 2 and terminals of the type described above are mounted in the connector, any two pieces of equipment can be coupled to each other.

Terminals in accordance with the invention are also adapted to be mated with dissimilar terminals which have contact portions adapted to extend between the contact spring 20, 22. One such terminal as shown in FIGS. 12-14 is fully disclosed in claimed in U.S. Pat. No. 3,208,030. A terminal 120 of this type comprises an L-shaped frame section having a sidewall 122 and a base 124. A retention lance 126 is struck from the base to engage the retention shoulder in a suitable cavity to prevent extraction of the terminal from the cavity while forward movement of the terminal through the cavity is prevented by a laterally extending ear 140 on the wall 122. The contact portion of the terminal 120 comprises an extension 128 of the base portion 124 which is of reduced width and which is reversely bent at 130 to define a rearwardly extending leaf 132. This leaf is again reversely bent adjacent to the rearward end of the frame section 122, 124 to define a forwardly and slightly downwardly extending leaf 136 which is upwardly directed at its end as shown at 138. A conventional crimp barrel means 142 are provided on the lefthand side of the terminal as viewed in FIG. 12 of the terminal to permit attachment to an electrical conductor.

Terminals of the type shown in FIG. 12 can be mated with each other by positioning two such terminals in opposed inverted relationship with their axes offset and moving them towards each other so that the upper leaf member 136 to each terminal bears against the underside of the base portion 124 of the other terminal. The base portion and the leaf member 132 of each terminal will then extend between the upper leaf 136 and the center section 132 of the other terminal as fully explained in the above identified U.S. Pat. No. 3,208,030.

Contact terminals in accordance with the instant invention can be mated with terminals of the type shown at 120 in FIG. 12 by positioning the two terminals in opposed relationship such that the reverse bend 130 of the terminal 120 is in alignment with the axes of the terminal 2 and the upper leaf 136 of the terminal 120 is in alignment with the sidewall 10 of the terminal 2. When the two terminals are thus positioned,the web 8 of the terminal 2 will be on the opposite side of the terminal pair from the wall 122 of the terminal 120. Upon movement of the two terminals towards each other, the central leaf 132 and portions of the lower central section 124 of terminal 120 will be received between the contact springs 20, 22 of the terminal 2 and the leaf spring 136 of the terminal 120 will bear against the external surface 24 of the contact spring 20 adjacent to the sidewall 10. As best shown in FIG. 14, the reduced widths of the springs of the terminal 2 provide clearance for the sidewall 122 of the terminal 120 so that the springs can move into the housing in which the terminal 120 is contained.

As is apparent from FIG. 13, three separate areas of contact between the terminal 120 and the terminal 2 are provided, and each contact area is maintained by the resilient force of a spring member.

The contact receiving cavity shown in FIGS. 13 for terminals of the type shown in FIG. 12 has a somewhat different interior configuration than the contact receiving cavity adapted for terminals of the type shown at 2 however, the contact terminals in accordance with the instant invention can be manufactured with dimensions such that the same number of cavities are provided in two connector blocks and at the same spacings so that the two blocks can be mated with each other even though one of the blocks has terminals of the type 120 therein and the other block has terminals of the type shown at 2 therein. It follows that any type of computer equipment provided with connectors having either of the two types of terminals therein can be electrically coupled to any other piece of computer equipment having one of the two types of terminals in its connectors.

An electrical connector in accordance with the invention, containing terminals in accordance with the invention, can also be mated with a connector having contact pins or blade type contact terminals therein as shown in FIG. 15. The blade terminal 144 is received between the opposed contact surfaces of the contact springs 20, 22 and should have a thickness which is sufficient to deflect the springs as indicated to establish contact force at the interface. The terminals 144 may be mounted in any suitable housing which will mate with the housing in which the terminals 2 are mounted.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only.

Claims

We claim:

1. A multi-contact electrical connector comprising an insulating housing having a plurality of discrete contact receiving cavities extending therethrough from the rearward face thereof to the mating face thereof, each of said cavities having an electrical contact terminal therein, each of said contact terminals comprising:

a substantially flat web having sidewalls extending from the longitudinal edges thereof,

means on said terminal at one end of said web securing said terminal to a conductor,

a pair of contact springs on said terminal at the other end thereof, each of said springs comprising an extension of one of said sidewalls,each of said springs extending from its respective sidewall and being reversely bent inwardly towards the other one of said springs, said springs having end portions extending rearwardly of said terminal on opposite sides of the axis thereof,

said springs having a width which is less than the width of said sidewalls, and the side edges of said springs being spaced from the edges of said sidewalls and from said web,

each of said terminals having its web and sidewalls disposed in one of said cavities and having portions of its contact springs extending forwardly beyond said mating face whereby,

said connector can be coupled to a complementary connector having contact terminals therein that have contact portions adapted to be received between the opposed surfaces of said contact springs of said connector.

2. A connector as set forth in claim 1 wherein said connector contains a plurality of rows of said cavities.

3. A pair of substantially identical connectors, said connectors being coupled to each other, each of said connectors comprising:

an insulating housing having at least one contact receiving cavity extending therethrough from its rearward face to its mating face,

an electrical contact terminal in said cavity, said terminal comprising a substantially flat web having sidewalls extending from the edges thereof, means on said terminal at one end of said web securing said terminal to a conductor,

a pair of contact springs on said terminal at the other end thereof, each of said springs comprising an extension of one of said sidewalls, each of said springs extending from its respective sidewall and being reversely bent inwardly towards the other one of said springs, said springs having end portions extending rearwardly of said terminal on opposite sides of the axis thereof,

said springs having a width which is less than the width of said sidewalls, and the side edges of said springs being spaced from the edges of said sidewalls and from said web,

said web and sidewalls being disposed in said cavity and said springs extending forwardly beyond said mating face,

said cavity having a laterally extending enlarged portion adjacent to, and opening into, said mating face,

the two connectors of said pair being coupled to each other in opposed inverted relationship with respect to each other with one contact spring and one sidewall of each of said terminals being received between the opposed surfaces of the contact springs of the other terminal.

4. An electrical connector comprising an insulating block having a contact-receiving cavity extending therethrough from the rearward face thereof to the mating face, and a terminal in said cavity, said terminal comprising

a web having sidewalls extending from the longitudinal edges thereof, said web and sidewalls defining a U-shaped cross-section,

means at one end of said terminal extending from said web for securing said terminal to a conductor,

a pair of contact springs extending from said terminal at the other end thereof, each of said contact springs comprising an extension of one of said sidewalls, each of said extensions projecting beyond said web and being reversely bent and having end portions extending inwardly towards said web and between said sidewalls, the end portions of said contact springs converging towards the axis of said terminal and

said springs having a width which is less than the width of said sidewalls, and the side edges of said springs being spaced from the edges of said sidewalls and from said web,

a retaining lance struck from said web, said lance extending obliquely rearwardly between said sidewalls,

said cavity having:

a first rectangular cross-sectional portion extending inwardly from said rearward face, a first pair of opposed walls of said first portion being spaced-apart by a distance equal to the spacing between said sidewalls, said sidewalls being against said first pair of opposed cavity walls, a second pair of opposed sidewalls which are spaced apart by a distance less than the height of said sidewalls, groove extending through said block and opening into one of said second pair of opposed sidewalls along the sides thereof, the marginal edge portions of said sidewalls being received in said grooves,

a boss extending from said one of said second opposed sidewalls defining a forward facing shoulder, said lance being against said boss to retain said terminal in said cavity,

a second rectangular portion of said cavity extending inwardly from said mating face, said second rectangular portion being enlarged on one side thereof which is in alignment with one of said second sides of said first rectangular section,

said contact springs extending through said second rectangular portion and beyond said mating face whereby said connector can be coupled with an identical connector in opposed reversed relationship to said connector.

5. A connector housing having at least one contact receiving cavity extending therethrough from its rearward face to its mating face, said cavity being adapted to receive an electrical contact terminal of the type comprising a web having sidewalls extending from the longitudinal edge thereof, a rearwardly directed retention lance struck from said web, a pair of contact springs extending forwardly from said sidewalls, said contact springs being reversely bent inwardly and extending rearwardly between said sidewalls, said cavity comprising:

a first rectangular cross sectional portion extending inwardly from said rearward face, a first pair of opposed walls of said first portion being spaced-apart by a distance equal to the spacing between said sidewalls, of said terminal said sidewalls being against said first pair of opposed cavity walls, a second pair of opposed sidewalls, which are spaced apart by a distance less than the height of said sidewalls, grooves extending through said block and opening into one of said second pair of opposed sidewalls along the sides thereof, the marginal edge portions of said sidewalls of said terminal being adapted to bear against said boss to retain said terminal in said cavity,

a second rectangular portion of said cavity extending inwardly from said mating face, said second rectangular portion being enlarged on one side thereof which is in alignment with one of said second sides of said first rectangular section whereby

said terminal can be inserted into said cavity from said rearward face of said housing upon movement of said terminal through said cavity and movement of edge portions of said sidewalls into said grooves until said lance snaps over, and lodges against, said boss.