WO1998043316A1

WO1998043316A1 - Low insertion force cluster block assembly

Info

Publication number: WO1998043316A1
Application number: PCT/US1998/005061
Authority: WO
Inventors: Henry H. Heimbrock
Original assignee: Standex International Corporation
Priority date: 1997-03-25
Filing date: 1998-03-16
Publication date: 1998-10-01
Also published as: AU6556798A

Abstract

A cluster block assembly (10) has a block (12) carrying terminals (30) in channels (20) thereof. The terminals (30) and block (12) are slidable relative to one another from a first position with a pin-receiving space (54) of the terminals (30) being spaced open to receive a compressor header pin (60) therein without substantial insertion force, and into a second position with the pin (60) in pin-receiving space (54) whereat the space (54) is closed down about the pin (60) to grip same. The terminal (54) includes at least one movable contact wall (52) and the block (12) includes a step (64) to deflect contact wall (52) to close down-pin receiving space (54) upon moving from the first position to the second position. Movable contact wall (52) may include an angled tip portion (172).

Description

LOW INSERTION FORCE CLUSTER BLOCK ASSEMBLY

Related Applications

This application claims priority to United States Provisional

Applications Serial Nos. 60/041,541 filed March 25, 1997 and 60/042,302 filed

April 1, 1997. Background of the Invention

I. Field of the Invention

The present invention relates to a cluster block assembly of the type used inside of hermetically-sealed compressors such as for refrigerators.

II. Description of Prior Art A typical refrigerator compressor assembly includes a two-part housing in which is hermetically sealed the motor and compressor system. The

housing parts are two shells that may be welded together to confine the motor

and compressor. In order to couple electrical power to the motor, it is necessary to make a connection from the outside into the housing interior. This connection is accomplished by a header mounted through the wall of one of the housing

shells. The header usually supports three electrically conductive pins projecting into the interior of the housing. The motor is connected to the header pins by a cluster block assembly.

A typical cluster block assembly includes a plastic cluster block with a plurality of channels, each of which carries a terminal coupled to a respective motor wire. The cluster block is inserted onto the header by shoving the cluster block over the header so that the pins of the header are received

through holes in the block to mate with the terminals contained within the block.

Examples of cluster block assemblies are shown in U.S. Patent Nos. 2,875,426; 3,101,985; 3,206,715; 3,566,341; 3,764,960; 3,853,388; 4,114,971; 4,740,177; 4,753,607; 4,758,178; 5,131,858; and 5,145,417 the disclosures of which are incorporated herein in their entireties by reference. A particular difficulty arises during the assembly process when

the cluster block assembly is to be inserted onto the pins of the header. The

shells are often sized to make a close fit to the motor and compressor contained

within, leaving little room to maneuver in order to properly insert the cluster block. Moreover, the header may be situated on the shell at a location that is not readily accessible. Still further, the insertion force required to shove the

terminals of the block over the header pins is quite high. As a consequence of the foregoing, proper insertion of the cluster block assembly is often quite

difficult to accomplish and, in some cases, impossible. The result is broken or defective connections that may lead to premature failure of the motor and/or compressor within the housing. Summary of the Invention

The present invention overcomes the abovementioned drawbacks by provision of a low insertion force cluster block assembly. To this end, and in accordance with the principles of the present invention, the terminals and cluster block are held together in sliding relationship such that in a first, assembly position, each terminal is sized to receive the associated header pin with little or no force required, and in a second, locked position, each terminal is squeezed

down about the pin to tightly grip to the pin. The terminals and cluster block are advantageously provided with components that cooperate to squeeze the terminal down onto the pin as the cluster block and terminals slide relative one

another after the pins have been easily slipped into the cluster block.

Each terminal may have opposed contact walls that define a pin- receiving space or area therebetween with a nominal spacing not less than, and

advantageously larger than, the diameter of the pin to be received. At least one

of the contact walls is movable toward the other contact wall to close down the

pin-receiving space and grip the pin. The cluster block channel has a narrowed

area whereat the contact walls of the terminal are urged together as the terminal

slides within the channel. The narrowed area may be defined by a step in the channel side wall such that in the first position, the contact walls of the terminal are situated in a relatively wide channel with an open pin-receiving space and in

the second position, the contact walls are in a narrower portion of the channel

with a closed down pin-receiving area. The step may include or be defined by a projection or land extending from the side wall into the channel to facilitate action of the contact walls in going from the first to the second position and to lock the terminal in the second position. A second projection or land may be positioned in the channel upstream (relative to terminal movement) of the step to maintain the terminal in the first position ready to be moved into the second position. To this end, a movable wall of the terminal has a tip that coacts with the respective projection(s) to hold the terminal in place within that channel. A distal segment of the tip may be angled outwardly from the remainder of the terminal wall. The second projection extends into the channel only a slight distance to provide a wedging action such that the terminal does not readily fall back out of the channel, but allows for a desirably large pin-receiving area. The

first, or locking, projection extends into the channel at the step beyond the plane of the downstream side wall such that upon relative sliding motion between the block and the terminal, a contact wall of the terminal jaw passes over that

projection and is locked in position in the narrower channel portion behind or

downstream of the projection and with the pin-receiving area compressed to grip

around the pin. The openings into the cluster block through which the header

pins pass may be elongated to facilitate sliding motion of the block relative to the

header.

The terminal may include a fixed wall or jaw and a movable wall

or jaw bent over from the fixed jaw at the front end of the terminal. The pin-

receiving space may be defined at the bend or spaced therefrom. To facilitate flexing of the walls of the terminal, the metal in the area of the bend may be relieved so as to create a hinge effect thereat.

By virtue of the foregoing, there is thus provided a cluster block assembly that overcomes the drawbacks associated with difficult-to-reach headers and problems caused by large insertion forces. With the low insertion force cluster block assembly of the present invention, the cluster block may be

easily positioned onto the header pins by simply being positioned or slid thereover with little force or manipulation required. Thereafter, the cluster block may be slid relative to the terminals such that the terminals clamp down on the header pins and are locked into that properly-inserted position. These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.

Brief Description of the Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention

and, together with the general description of the invention given above and the

detailed description of the embodiment given below, serve to explain the

principles of the present invention.

Fig. 1 is a perspective, partially broken away view of a first cluster block assembly in accordance with the principles of the present invention,

and showing the assembly in the locked position;

Fig. 2 is a top view of the assembly of Fig. 1 with the top wall of

the block removed and showing the assembly in the assembly position; Fig. 3 is a top view of a portion of a channel and terminal of the assembly of Fig.1 with the top wall of the block removed and in the locked position;

Fig. 4 is a perspective, partially broken away view of a second

cluster block assembly in accordance with the principles of the present invention, and showing the assembly in the locked position;

Fig. 5 is a top view of the assembly of Fig. 4 with the top wall of

the block removed and showing the assembly in the assembly position;

Fig. 6 is a top view of a portion of a channel and terminal of the

assembly of Fig. 4 with the top wall of the block removed and in the locked position;

Fig. 7 is an end view of a terminal of Fig. 4 taken along line 7-7 of Fig. 6 showing the relief aperture; and

Fig. 8 is a side cross-sectional partial view of a compressor with

the top shell removed for purposes of explaining the principles of the present

invention.

Detailed Description of the Drawings

With reference to Figs.1-3, there is shown a first cluster block

assembly 10 in accordance with the principles of the present invention. To this

end, assembly 10 includes an insulative, plastic cluster block 12 having a bottom

wall 14 spaced from and parallel to top wall 16, and interconnected by four

parallel side walls 18 to define three rectangular cross-section passageways or

channels 20 extending longitudinally from back end 22 to front end 24 of block

12. Top wall 16 includes three equiangularly spaced, elongated or elliptical pin- access openings 26 extending transversely therethrough and communicating with a respective channel 20 for purposes to be described hereinafter.

Held within each channel 20 is an electrically conductive terminal 30 having a wire-retaining back end 32 and a pin-receiving front end 34. Wire-

retaining back end 32 has a first collar 35 that grips around the insulation 36 of a motor or magnet wire 38, and a second, inboard collar 40 that grips around and electrically connects to the conductors 42 of wire 38. Pin-receiving front end 34

of each terminal 30 includes a pair of spaced-apart contact walls 50 and 52 that are in confronting relationship to define a pin-receiving area or space 54 therebetween. Contact walls 50 and 52 are normally urged apart by the

resiliency of the metal of terminal 30 such that the pin-receiving space 54 is nominally not smaller than, and is advantageously larger than, the nominal diameter of a pin 60 of a header 62 (Fig. 8) to be received therein. In the

embodiment shown in Figs. 1-3, the contact walls comprise a generally flat, fixed wall 50 and a movable jaw 52. Movablejaw 52 is bent over from fixed wall 50

at the distal end 55 and includes a semi-circular arc portion 56 spaced from distal

end 55 to give the terminal 30 a J-shape or fish-hook shape to the front end 34. With such a shape, the jaw 52 is movable toward the fixed wall 50. Portion 56 is

designed to conform closely to the surface of pin 60 against which it will be

placed.

With particular reference to Fig. 3, it may be seen that each

channel 20 has a relatively wide upstream portion 20a and a narrower

downstream portion 20b brought about by upstream side wall portion 18a being

thinner than downstream wall portion 18b. The transition to narrow channel portion 20b (i.e., to thicker wall portion 18b) occurs at a step 64 in sidewall 18 facing toward movable terminal jaw 52. Step 64 may include or be defined by a first projection or land or detent 66. A second projection or land or detent 68 is advantageously formed in side wall 18 facing toward movable terminal jaw 52 and spaced from step 64 for purposes to be described hereinafter. Projection 66

is formed at step 64 and extends into channel portion 20b beyond a plane 70 defined by the interior of wall portion 18b such that a segment of channel 20 thereat is narrower than channel portion 20b. Second projection 68 may be formed upstream of step 64 and extends into channel portion 20a short of plane 70.

Each terminal 30 is loaded into a respective channel 20 by

inserting the front end 34 thereof through the back end 22 of block 12 until jaw

52 rides up over projection 68 and comes to rest adjacent intermediate side wall portion 18' at step 64 and against projection 66 to define a first or assembly position of cluster block assembly 10 as shown in Fig. 2. In this first position of

assembly 10, tip 72 of jaw 52 confronts projection 68 to prevent terminal 30

from falling back out of cluster block channel 20. Also, fixed wall 50 is adjacent

the opposite side wall 18 of channel 20 with pin-receiving space 54 coincident

with one end 76 of elliptical opening 26 to receive pin 60 therethrough. Further,

space 54 in this first position is not less than, and is advantageously larger than, the diameter of pin 60 to be received therein (as exemplified by a substantial aspect of arcuate portion 56 extending beyond the confines of opening 26 as

seen in Fig. 2) such that pin 60 may be easily received such as by siding into

terminal 30 with little or no insertion force. Once pins 60 are all slidably received within pin-receiving spaces 54 of respective terminals 30, relative sliding motion of block 12 and terminals 30 will cause each jaw 52 to ride up over a respective projection 66 at step 64 and onto side wall portion 18b in narrower channel portion 20b to a second, locked position of assembly 10 as shown in Figs. 1 and 3. As a consequence,

each jaw 52 is urged in a camming action towards related contact wall 50 thereby closing down pin-receiving space 54 and gripping pin 60 therein by

coaction of wall 50 and arcuate portion 56 of wall 52. Jaw 52 and portion 56 are formed such that the pin-receiving space 54 in the locked position will be not more than the diameter of pin 60 so that with pin 60 in place, jaw 52 will tend to

wrap slightly around pin 60 as terminal 30 moves into the locked position. In this locked position, it will be seen that most of portion 56 of wall 52 is now within the confines of hole 26 (as seen in Fig. 3), and tip 72 confronts projection 66 to lock terminal 30 into the pin-holding position. Relative sliding motion of block 12 and terminals 30 will normally

be by sliding block 12 in a direction from right to left as viewed from Fig. 2 such

that pins 60 cooperate to hold terminals 30 in their same position relative pins 60. As a consequence, in the locked position of assembly 10, pin-receiving

spaces 54 and pins 60 will now be coincident with and at the opposite end 78 of elliptical openings 26. It will thus be appreciated that the elongated shape and positioning of openings 26 in wall 16 serve to maintain pin access to spaces 54

between the first and second positions of assembly 10. In the embodiment

shown in Figs. 1-3, and for a standard header 62 and pins 60, terminals 30 may

be tin plated phosphorous bronze or tin plated Olin alloy 195, with a nominal open-jaw distance (D) outside of channel 20 of about .200 to .211 inches. Side walls 18 are sized and positioned such that the narrow channel portion 20a has a

width (measured between adjacent side walls 18) of about .200 inches while narrower portion 20b has a narrower width of about .180 inches. Land 66 may project into channel 20 such that the width thereat is about .172 inches and land

68 may project into the channel to define a width thereat of about .185 inches. The trailing edge of land 68 and the leading edge of land 66 are angled to permit tip end 72 to rest therebetween as seen in Fig. 2.

With further reference to Figs.4-6, there is shown a second cluster block assembly 110 in accordance with the principles of the present invention. To this end, assembly 110 includes an insulative, plastic cluster block

112 having a bottom wall 114 spaced from and parallel to top wall 116, and interconnected by four parallel side walls 118 to define three rectangular cross- section passageways or channels 120 extending longitudinally from back end 122

to front end 124 of block 112. Top wall 116 includes three equiangularly spaced, elongated or elliptical pin-access openings 126 extending transversely

therethrough and communicating with a respective channel 120 for purposes to

be described hereinafter.

Held within each channel 120 is an electrically conductive

terminal 130 having a wire-retaining back end 132 and a pin-receiving front end

134. Wire-retaining back end 132 has a first collar 135 that grips around the

insulation 36 of a motor or magnet wire 38, and a second, inboard collar 140

that grips around and electrically connects to the conductors 42 of wire 38. Pin-

receiving front end 134 of each terminal 130 includes a pair of spaced-apart contact walls 150 and 152 that are in confronting relationship to define a pin- receiving area or space 154 therebetween. Contact walls 150 and 152 are

normally urged apart by the resiliency of the metal of terminal 130 such that the pin-receiving space 154 is nominally not smaller than, and is advantageously larger than, the nominal diameter of a pin 60 of a header 62 (Fig. 8) to be received therein. In the embodiment shown in Figs. 4-6, the contact walls comprise a generally flat, fixed wall 150 and a movable jaw 152. Movable jaw

152 is bent over from fixed wall 150 at the distal end 155 and includes a semi¬

circular arc portion 156 at distal end 155 to give the terminal 130 a J-shape or fish-hook shape to the front end 134. With such a shape, the jaw 152 is movable toward the fixed wall 150 to close down space 154. Portion 156 is designed to conform closely to the surface of pin 60 against which it will be placed. Jaw 152 has a first segment 153 extending from arc portion 156 to a bent tip portion or

free tip end 172 that extends at approximately 75 ° to normal for purposes to be

described hereinafter.

With particular reference to Fig. 6, it may be seen that each

channel 120 has a relatively wide upstream portion 120a and a narrower downstream portion 120b brought about by upstream side wall portion 118a

being thinner than downstream wall portion 118b. The transition to narrow

channel portion 120b (i.e., to thicker wall portion 118b) occurs at a step 164 in

sidewall 118 facing toward movable terminal jaw 152. Step 164 may include or

be defined by a pair of aligned first projections, lands, or detents 166, one near top wall 116 and one near bottom wall 114. A second projection, land or detent

168 is advantageously formed in side wall 118 facing toward movable terminal jaw 152 and spaced from step 164 for purposes to be described hereinafter, although it will be noted that projection 168 is sized in height to be about equal to the spacing between projections 166, with projections 166 and 168 being sized to facilitate moldability. Walls 118 supporting projections 166 and 168 may also be relieved for moldability in line with projection 168 as at 169.

Projections 166 are formed at step 164 and extend into channel portion 120b beyond a plane 170 defined by the interior of wall portion 118b such that a segment of channel 120 thereat is narrower than channel portion 120b. Second

projection 168 may be formed upstream of step 164 and extends into channel portion 120a short of plane 170.

Each terminal 130 is loaded into a respective channel 120 by inserting the front end 134 thereof through the back end 122 of block 112 until jaw 152 rides up over projection 168 and comes to rest adjacent intermediate side wall portion 118' at step 164 and against projection 166 to define a first or assembly position of cluster block assembly 110 as shown in Fig. 5. In this first

position of assembly 110, bent-out tip portion 172 of jaw 152 fits within the

space defined between projections 166 and 168 and in confronting relationship

to projection 168 to prevent terminal 130 from falling back out of cluster block

channel 120. Also, fixed wall 150 is adjacent the opposite side wall 118 of channel 120 with pin-receiving space 154 coincident with one end 176 of

elliptical opening 126 to receive pin 60 therethrough. Further, space 154 in this

first position is not less than, and is advantageously larger than, the diameter of

pin 60 to be received therein such that pin 60 may be easily received such as by

siding into terminal 130 with little or no insertion force. By way of example, in the assembly position, for .125 inch diameter pins 60, space 154 has a radius of about .126 inch.

Once pins 60 are all slidably received within pin-receiving spaces 154 of respective terminals 130, relative sliding motion of block 112 and

terminals 130 will cause each tip portion 172 to ride up over a respective pair of projections 166 at step 164 and onto side wall portion 118b in narrower channel portion 120b to a second, locked position of assembly 110 as shown in Figs. 4 and 6. As a consequence, each jaw 152 is urged in a camming action towards related contact wall 152 thereby closing down pin-receiving space 154 and gripping pin 60 therein by coaction of wall 150 and arcuate portion 156 of wall

152. With reference to Fig. 7, to facilitate the closing down action, metal may be

relieved from terminal 130 at bend 155 to define an aperture 180 (such as a .125 inch diameter circular opening before the metal is bent as at 155) thereat. With aperture 180, flexing of jaw 152 results in a hinge action at distal end bend 155 such that wall 150 will not be readily pulled away from associated side wall 118

of channel 120. Jaw 152 and portion 156 are formed such that the pin-receiving

space 154 in the locked position will be not more than the diameter of pin 60 so

that with pin 60 in place, jaw 152 will tend to wrap slightly around pin 60 as

terminal 130 moves into the locked position. In this locked position, it will be seen that most of portion 156 of wall 152 is now within the confines of hole 126

(as seen in Fig. 6), and tip portion 172 confronts projections 166 to lock terminal

130 into the pin-holding position.

Relative sliding motion of block 112 and terminals 130 will

normally be by sliding block 112 in a direction from right to left as viewed from Fig. 5 such that pins 60 cooperate to hold terminals 130 in their same position relative pins 60. As a consequence, in the locked position of assembly 110, pin- receiving spaces 154 and pins 60 will now be coincident with and at the opposite end 178 of elliptical openings 126. It will thus be appreciated that the elongated

shape and positioning of openings 126 in wall 116 serve to maintain pin access

to spaces 154 between the first and second positions of assembly 10. In the embodiment shown in Figs. 4-6, and for a standard header 62 and pins 60, terminals 130 may be tin plated phosphorous bronze or tin plated Olin alloy 195, with a nominal open-jaw distance (D) outside of channel 120 of about .200 inches. Side walls 118 are sized and positioned such that the narrow channel portion 120a has a width (measured between adjacent side walls 118) of about .200 inches while narrower portion 120b has a narrower width of about .180

inches. Lands 166 may project into channel 120 such that the width thereat is about .172 inches and land 168 may project into the channel to define a width thereat of about .185 inches. The trailing edges of lands 168 and the leading edges of lands 166 are angled and spaced apart just enough (about .222 inches)

to permit tip end 172 to rest therebetween, as seen in Fig. 5.

To facilitate correct alignment of terminal 130 upon insertion into

channel 120, terminal 130 is provided with a location tab 190 that mates with alignment slot 192 formed in bottom wall 114 of each channel 120. Tab 190

depends from fixed wall 150, with slot 192 extending between front end 124 and

back end 122 adjacent wall 118 against which terminal wall 150 is to be

positioned. In use, and with reference to Fig. 8, cluster block assembly 10 is

to be inserted onto the pins 60 of a header 62 which is mounted to a wall 200 of a compressor housing shell 202. Within shell 202 is also mounted a compressor and motor system 204 as is conventional. However, it will be seen with reference to Fig. 8 that in some circumstances, the size of shell 202 and position of compressor and motor system 204 are such that access to pins 60 may be

quite difficult. With the cluster block assembly 10 or 110 of the present

invention, such problems are minimized because the assembly 10 or 110 (in the first position) may simply be dropped down (while holding onto wires 38) until openings 26 or 126 are coincident with pins 60. Assembly 10 or 110 is then slid gently over pins 60 without substantial insertion force, and where pin-receiving spaces 54 or 154 are larger than the diameter of pins 60 desirably little or no

insertion force is needed, so that pins 60 protrude into pin-receiving spaces 54 or

154. Thereafter, block 12 or 112 may be pulled (such as with a pry bar or the like) upwardly. That upward motion, and cooperation of pins 60 with terminals

30 or 130, causes block 12 or 112 to move or slide relative to terminals 30 or

130 such that jaws 52 or 152 will deflect as they ride up over projections 66 or

166 and onto the narrow channel portions 20b or 120b whereat assembly 10 or

110 is locked into the second position with the pins 60 firmly gripped by terminal

contact walls 50 or 150 and arcuate portions 56 or 156 of terminal contact walls

52 or 152.

By virtue of the foregoing, there is thus provided a low insertion force cluster block assembly by which to facilitate manufacture of compressor

assemblies even where access to the header pins is difficult. While the present invention has been illustrated by the description

of an embodiment thereof, and while the embodiment has been described in

considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example, while terminals 30 are shown having only one contact wall movable relative the other wall, it will be

appreciated that terminals could be employed with both contact walls 50 (150) and 52 (152) being movable toward each other. Additionally, opposed projections 66 (166) and/or 68 (168) could be provided in each channel 20 (120) to facilitate movement of both walls of the terminal 30 (130). Still further, either or both of projections 66 (166) and 68 (168) could be eliminated. In this regard,

it will be appreciated that step 64 (164) may alone be sufficient to provide the necessary camming action on contact wall 52 (152) to place assembly 10 (110) into the second position. The invention in its broader aspects is, therefore, not

limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general

inventive concept.

Having described the invention, what is claimed is:

Claims

CLAIMS: ^{' 17 "}

(1) A cluster block assembly (10,110) comprising a cluster bock (12, 112) having walls (14, 114, 16, 116, 18, 118) defining a channel (20, 120) extending through the block (12, 112), and a conductive terminal (30, 130) having a pair of

contact walls (50,52, 150, 152) being movable relative to each other and defining a pin-receiving space (54, 154) therebetween, characterised by a step (64, 164) in the channel (20, 120) whereby to define a narrowing of the channel (20, 120), and the terminal (30, 130) and block (12, 112) having a first position in which the pin-receiving space (54, 154) is not less than a diameter of a pin (60) to be received therein and a second position wherein the pin-receiving space (54, 154)

is closed down whereby to grip said pin (60), the terminal (30) being slidably situated in the cluster block channel (20, 120) for relative movement from the first position to the second position with the step (64, 164) cooperating with at least one of the contact walls (50, 52, 150, 152) to close down the pin-receiving

space (54, 154).

(2) A cluster block assembly comprising a cluster bock (12, 112) having a

channel (20, 120) extending through the block (12, 112), and a conductive terminal (30, 130) having a pair of contact walls (50,52, 150, 152) being movable relative to each other and defining a pin-receiving space (54, 154)

therebetween, characterised in that the channel (20, 120) of the body (12, 112)

has first (20a, 120a) and second (20b, 120b) channel portions with the second

channel portion (20b, 120b) being narrower than the first channel portion (20a,

120a), the terminal (30, 130) being slidably situated in the cluster block channel

(20, 120) such that in a first position at least one of the contact walls (50, 150, 52, 152) cooperates with the first channel portion (20a, 120a) such that the pin- receiving space (54, 154) is not less than a diameter of a pin (60) to be received therein, and in a second position at least one of the contact walls (50, 150, 52, 152) cooperates with the second channel portion (20b, 120b) such that the pin- receiving space (54, 154) is closed down whereby to grip said pin (60), and the cluster block (12, 112) including a pin-access opening (26, 126) communicating

with the channel (20, 120) and being sized and positioned to be coincident with the pin-receiving space (54, 154) in both said first and second positions.

(3) A cluster block assembly as claimed in Claim 1 further characterised in that the cluster block (12, 112) includes a pin-access opening (26, 126) through one of the walls (16, 116) thereof, said opening (26, 126) being sized and

positioned to be coincident with the pin-receiving space (54, 154) in both said

first and second positions.

(4) A cluster block assembly as claimed in Claim 2 wherein the cluster block

(12, 112) includes a step (64) at an interface of the first and second channel

portions (20a, 120a, 20b, 120b).

(5) A cluster block assembly as claimed in any preceding Claim wherein the block (12, 112) includes a first projection (66, 166 or 68, 168) extending into the

channel (20, 120). (6) A cluster block assembly as claimed in Claim 5 when dependent from

either Claim 1 or Claim 4 wherein the step (64, 164) includes the first projection (66, 166).

(7) A cluster block assembly as claimed in Claim 6 further including a second projection (68, 168) spaced from the step (64, 164) and extending into the

channel (20, 120).

(8) A cluster block assembly as claimed in Claim 5 when dependent from either Claim 2 or Claim 4 wherein the first projection (66, 166) extends into the

channel (20, 120) adjacent the second channel portion (20b, 120b).

(9) A cluster block assembly as claimed in Claim 5 when dependent from either Claim 2 or Claim 4 wherein the first projection (66, 166) extends into the channel (20, 120) to define a segment of the channel (20, 120) that is narrower than the second channel portion (20b, 120b).

(10) A cluster block assembly as claimed in Claim 8 or Claim 9 further

including a second projection (68, 168) extending into the first channel portion

and being spaced from the first projection (66, 166).

(11) A cluster block assembly as claimed in any preceding Claim wherein one

of the terminal contact walls (52, 152) includes a tip (72, 172) cooperating with

the cluster block projection (66, 166, 68, 168). (12) A cluster block assembly as claimed in Claim 11, the tip (172) being angled from a remainder (153) of the one terminal wall (52, 152).

(13) A cluster block assembly as claimed in any preceding Claim wherein the

terminal contact walls (50, 150, 52, 152) constitute a fixed wall (50, 150) and a movable jaw (52, 152).

(14) A cluster block assembly as claimed in any preceding Claim wherein the terminal (130) has a distal end (155), the pin-receiving space (154) being defined

at the distal end (155).

(15) A cluster block assembly as claimed in any of Claims 1 through 14 wherein the terminal (30) has a distal end (55), the pin-receiving space (54)

being spaced from the distal end (55).

(16) A cluster block assembly as claimed in any preceding Claim

wherein the terminal (130) includes a locating tab (190) and the cluster block

(112) includes an alignment slot (192) whereby to align the terminal (130) for

insertion into the cluster block (112).

(17) A conductive terminal (130) for a cluster block assembly (110) having a

pair of contact walls (150, 152) defined by a fixed wall (150) and a movable wall

(152) joined at a distal end bend (155), the pair of contact walls (150, 152)

defining a pin-receiving space (154) having a nominal radius not less than a predetermined radius and being reducible upon movement of the movable wall (152) toward the fixed wall (150), the movable wall (152) terminating in a free tip end portion (172) and having a segment (153) extending between the free tip

end portion (172) and the pin-receiving space (154), characterised in that the free tip end portion (172) is being angled outwardly from the segment (153) in a direction away from the fixed wall (150).

(18) A terminal as claimed in Claim 17, the distal end bend (155) including an

aperture (180) therethrough.

(19) A terminal as claimed in either Claim 17 or Claim 18 wherein the pin- receiving space (154) is defined at the distal end bend (155).

(20) A terminal as claimed in either Claim 17 or Claim 18 wherein the pin-

receiving space (154) is spaced from the distal end bend (155).

(21) A terminal as claimed in any of Claims 17 through 19 further including a locating tab (190).

(22) A terminal as claimed in any of Claims 17 through 19, the locating tab

(190) depending from the fixed wall (150).

(23) A method of mounting a cluster block assembly (10, 110) having a

cluster block (12, 112) carrying an electrical terminal (30, 130) therein to a header (62) of a compressor assembly, the header (62) including a pin (60) to be

inserted into the block (12, 112) and into electrical engagement with the terminal (30, 130), the method characterised by sliding the cluster block assembly (10, 110) onto the header (62) with the terminal (30, 130) situated in the block (12,

112) in a first position whereat a pin-receiving space (54, 154) of the terminal

(30, 130) is not less than a diameter of the pin (60), such that the pin (60) is situated within said pin-receiving space (54, 154) without substantial insertion force, and moving the cluster block (12, 112) and terminal (30, 130) relative to

each other into a second position while the pin (60) is in the pin-receiving space (54, 154) such that the pin-receiving space (54, 154) is closed down about the

pin (60) whereby to grip same.

(24) A method as claimed in Claim 23 wherein the cluster block (12, 112) includes an elongated pin-access opening (26, 126), the method further comprising inserting the pin (60) through the opening (26,126) as the cluster block assembly (10, 110) is slid onto the header (60), and moving the pin (60)

from one end (76, 176) of the opening (26, 126) to another end (78, 178) of the

opening (26, 126) when the cluster block (12, 112) and terminal (30, 130) move

relative one another from said first position to said second position.