GB2154074A

GB2154074A - Electric plug having part-insulated pins

Info

Publication number: GB2154074A
Application number: GB08402226A
Authority: GB
Inventors: Graham John Spencer; Kenneth Jeffrey Bailey
Original assignee: Delta Acc & Domestic Switch
Current assignee: Delta Acc & Domestic Switch
Priority date: 1984-01-27
Filing date: 1984-01-27
Publication date: 1985-08-29
Also published as: GB8402226D0; JPS60165069A

Abstract

An electric plug has at least two insulated pins (1), each of which has a rebate, in which an insulating sleeve (4) is located. A terminal member (5) is secured to the inner end of each pin (1) and extends laterally beyond the pin and sleeve. The pins are located in passages (12) in a plug base (10) with the tip and a part of the insulating sleeve (4) protruding. A shoulder (14) formed on the base then receives the laterally extending part of the terminal member (5) and prevents outward movement of the pin from the base. A cover (11) is secured to the base and retains the pin against inward movement. <IMAGE>

Description

SPECIFICATION Electric plug having part-insulated pins This device relates to an electric plug having partinsulated pins, designed to minimise the danger of a user's fingers contacting the metal portions of the pins while the latter are still in electrical contact with the supply. Generally, only the live and neutral pins of a plug are so part-insulated.

In accordance with one aspect of the present invention, an electric plug having part-insulated pins comprises at least two plug pins carrying insulating sleeves which are located in rebates in the pins and extend to the inner ends of the pins; for each such pin a terminal member which is secured to the inner end of the pin and which extend laterally beyond the pin in at least one direction so as to retain the sleeve against inward movement relative to the pin; a plug base which is internally recessed and which has passages therethrough receiving said pins; and a plug cover securable to the base, the terminal members being engaged by both the base and the cover to restrict the movement of the pins relative to the base.

Each of said part-insulated pins may additionally have a peg located in a cross bore in the pin and protruding therefrom and received in recesses in the base to assist retaining the pin in the base against outward movement. Further, each insulating sleeve may be formed with ribs which engage with the walls of the passage and retain the pin in position when the cover is removed from the base.

The invention will be more readily understood by way of example from the following description of an electric plug in accordance therewith, reference being made to the accompanying drawings, in which Figures 1 and 2 show a pin in end view and side view, respectively, Figures 3 and 4 are sectional views, taken at right angles to one another of the plug and show a pin in position in the plug, Figure 5 is a plan view of the terminal, shown in Figures 3 and 4 as secured to the pin, Figure 6 illustrates a peg, Figures 7a and 7b are respectively side and end views of an insulating sleeve, and Figures 8a, 8b and 8c show in side view, end view and plan modified pin carrying a fuse clip.

The pin 1 shown in Figures 1 and 2 has a generally rectangular cross section and includes a terminal spade portion 2 and an integral reduced or rebated portion 3. An integral rivet shank 4 projects from the end distant from the spade portion 2.

The rebated portion 3 of the pin receives an electrically insulating sleeve 4, which is a close fit on the rebated portion and which has a length equal to that portion. The sleeve is preformed and is made of insulating material.

The pin 1 is secured to a terminal member, which in Figures 3 and 4 is illustrated as an L-shaped terminal bracket 5 having a hole therein to receive rivet peg 4 which is then turned over to secure the terminal bracket to the pin. The terminal bracket 5 is, in one dimension, wider than the corresponding dimension of the pin 1 and thereby extends beyond the perimeter of the pin as shown in Figure 4. The terminal bracket 5 has secured to it a terminal 6 having a cross bore 7 and a threaded screw 8. A corresponding hole is formed in the bracket 5, aligned with-the hole 7 of the terminal.

In Figures 3 and 4 the plug base is shown at 10 and the plug cover at 11. Plug base 10 has a passage 12 to receive with a close fit each sleeved pin 1. The passage is widened at 13 to receive the terminal bracket 5 and to form a shoulder 14 against which the terminal bracket 5 fits, as shown in Figure 4.

The plug cover 11 is, as usual, securable to the plug base 10 and has a recess 15 to receive the head of the terminal screw 8. When cover 11 and base 10 are secured together, the inner wall of the cover 11 engages the end of the terminal bracket 5, again as shown in Figure 4. Accordingly, the pin 1 is held against lengthwise movement relative to the base 10, by the engagement of bracket 5, by the shoulder 14 and by the cover 11. In addition, the sleeve 4 on each pin 1 is retained in position on the pin by the engagement of the sleeve at one end with the spade portion 2 and at the other end by the engagement with the bracket 5.

The sleeve 4 may be formed with external ribs 20 which, when the pin is located in the passage 12 engage with the wall of the passage and retain the pin in position in the base 10 when the cover 11 is removed. Further, a rivet peg 21 having a head 22 and a reduced shank 23 may be located in a cross bore 24 in the pin (see Figure 2), the head 22 then engaging shoulders 25 formed in the passage. The rivet peg prevents the pin from passing outwardly through the base and removes strain from the riveted bracket 5. When the peg 21 is employed, sleeve 4 is formed with clearance for the peg; that clearance may be a hole, or a slot 26 as shown if that aids the moulding process.

Other terminal members may be secured to the pins 1 in place of the bracket 5 and terminal 6. Thus, Figures 8a, 8b and 8c illustrate a fuse clip 30 which is riveted to the pin by means of the rivet peg 4. The base of the clip 30 is similar to that of the bracket 5 and engages the shoulders 14 (Figure 4). Similarly, the extremities of the clip are engaged by the cover 11 when the latter is secured to the base 10, so that the pin is again retained in position in the base.

1. An electric plug comprising at least two plug pins carrying insulating sleeves which are located in rebates in the pins and extend to the inner ends of the pins; for each pin, a terminal member which is secured to the inner end of the pin and which extends laterally beyond the pin in at least one direction so as to retain the sleeve against inward movement relative to the pin; a plug base which is internally recessed and which has passages therethrough to receive the pins; and a plug cover securable to the base, the terminal members being engaged by both the base and the cover to restrict lengthwise movement of the pins relative to the base.

2. An electric plug according to claim 1, in which

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Electric plug having part-insulated pins This device relates to an electric plug having partinsulated pins, designed to minimise the danger of a user's fingers contacting the metal portions of the pins while the latter are still in electrical contact with the supply. Generally, only the live and neutral pins of a plug are so part-insulated. In accordance with one aspect of the present invention, an electric plug having part-insulated pins comprises at least two plug pins carrying insulating sleeves which are located in rebates in the pins and extend to the inner ends of the pins; for each such pin a terminal member which is secured to the inner end of the pin and which extend laterally beyond the pin in at least one direction so as to retain the sleeve against inward movement relative to the pin; a plug base which is internally recessed and which has passages therethrough receiving said pins; and a plug cover securable to the base, the terminal members being engaged by both the base and the cover to restrict the movement of the pins relative to the base. Each of said part-insulated pins may additionally have a peg located in a cross bore in the pin and protruding therefrom and received in recesses in the base to assist retaining the pin in the base against outward movement. Further, each insulating sleeve may be formed with ribs which engage with the walls of the passage and retain the pin in position when the cover is removed from the base. The invention will be more readily understood by way of example from the following description of an electric plug in accordance therewith, reference being made to the accompanying drawings, in which Figures 1 and 2 show a pin in end view and side view, respectively, Figures 3 and 4 are sectional views, taken at right angles to one another of the plug and show a pin in position in the plug, Figure 5 is a plan view of the terminal, shown in Figures 3 and 4 as secured to the pin, Figure 6 illustrates a peg, Figures 7a and 7b are respectively side and end views of an insulating sleeve, and Figures 8a, 8b and 8c show in side view, end view and plan modified pin carrying a fuse clip. The pin 1 shown in Figures 1 and 2 has a generally rectangular cross section and includes a terminal spade portion 2 and an integral reduced or rebated portion 3. An integral rivet shank 4 projects from the end distant from the spade portion 2. The rebated portion 3 of the pin receives an electrically insulating sleeve 4, which is a close fit on the rebated portion and which has a length equal to that portion. The sleeve is preformed and is made of insulating material. The pin 1 is secured to a terminal member, which in Figures 3 and 4 is illustrated as an L-shaped terminal bracket 5 having a hole therein to receive rivet peg 4 which is then turned over to secure the terminal bracket to the pin. The terminal bracket 5 is, in one dimension, wider than the corresponding dimension of the pin 1 and thereby extends beyond the perimeter of the pin as shown in Figure 4. The terminal bracket 5 has secured to it a terminal 6 having a cross bore 7 and a threaded screw 8. A corresponding hole is formed in the bracket 5, aligned with-the hole 7 of the terminal. In Figures 3 and 4 the plug base is shown at 10 and the plug cover at 11. Plug base 10 has a passage 12 to receive with a close fit each sleeved pin 1. The passage is widened at 13 to receive the terminal bracket 5 and to form a shoulder 14 against which the terminal bracket 5 fits, as shown in Figure 4. The plug cover 11 is, as usual, securable to the plug base 10 and has a recess 15 to receive the head of the terminal screw 8. When cover 11 and base 10 are secured together, the inner wall of the cover 11 engages the end of the terminal bracket 5, again as shown in Figure 4. Accordingly, the pin 1 is held against lengthwise movement relative to the base 10, by the engagement of bracket 5, by the shoulder 14 and by the cover 11. In addition, the sleeve 4 on each pin 1 is retained in position on the pin by the engagement of the sleeve at one end with the spade portion 2 and at the other end by the engagement with the bracket 5. The sleeve 4 may be formed with external ribs 20 which, when the pin is located in the passage 12 engage with the wall of the passage and retain the pin in position in the base 10 when the cover 11 is removed. Further, a rivet peg 21 having a head 22 and a reduced shank 23 may be located in a cross bore 24 in the pin (see Figure 2), the head 22 then engaging shoulders 25 formed in the passage. The rivet peg prevents the pin from passing outwardly through the base and removes strain from the riveted bracket 5. When the peg 21 is employed, sleeve 4 is formed with clearance for the peg; that clearance may be a hole, or a slot 26 as shown if that aids the moulding process. Other terminal members may be secured to the pins 1 in place of the bracket 5 and terminal 6. Thus, Figures 8a, 8b and 8c illustrate a fuse clip 30 which is riveted to the pin by means of the rivet peg 4. The base of the clip 30 is similar to that of the bracket 5 and engages the shoulders 14 (Figure 4). Similarly, the extremities of the clip are engaged by the cover 11 when the latter is secured to the base 10, so that the pin is again retained in position in the base. CLAIMS

2. An electric plug according to claim 1, in which the base is formed with shoulders against which the laterally extending parts of the terminal members sit when the pins are received in the passage.

3. An electric plug according to claim 1 or claim 2, in which each of the pins has a peg located in a cross-bore in the pin and protruding therefrom, and each of the passages has a shoulder against which the peg is engaged to assist in retaining the pin in the base against outward movement.

4. An electric plug according to claim 3, in which each insulating sleeve is formed with a hole or a slot to accommodate the peg.

5. An electric plug according to any one of the preceding claims, in which each sleeve has external ribs which engage the walls of the passage and retain the pin in position when the cover is removed from the base.

6. An electric plug substantially as herein described with reference to the accompanying drawings.