GB2278557A - Variable crimp height device. - Google Patents

Abstract

An Infinitely Variable Crimp Height Device that can achieve variation of Crimp Height to obtain the optimum Crimp Height for a given wire size within the Maximum and Minimum range of the wire sizes of any specific electrical terminal. The selected position is achieved by the rotation of a Wire Disc Fig 4 which can be locked in the chosen position by a locking screw. The wire disc Fig 4 has a helical undersurface which contacts the helical upper surface of a fixed helix Fig 5 located below the wire disc thus providing variation in the crimp height by increasing or decreasing the effective length of the applicator ram Fig 7. The Device is capable of transmitting the thrust required to achieve the crimp form from a power press and this thrust is balanced either side of the ram centreline. It can be fitted to conventional Mini-Applicator Tools in place of the present methods currently used. <IMAGE>

Description

Infinitely Variable Crimp Height Device itfl+,iii+,+iti,+t++ti++t++++tii,if+f This invention relates to an infinitely variable crimp height device.

Such a device is for use on a Mini-Applicator Tool used for crimping electrical terminals, contacts, or connectors, to electrical wire.

The usual method of varying the crimp heights required to suit different wire sizes, is by a rotatable disc which has a pair of equal pre-determined thickness pads diametrically opposed to each other. The reason for the two pads is that the power presses in which these Applicators are fitted have two pads on the underside of their ram and disposed either side of the centre line to impart the downward force through the Applicator ram to compress the crimped joint. However, being able to select only one of four alternative positions restricts the versatility of the Tool by limiting the selected crimp height to only one of four choices. Modern technology requires a very accurate crimp height to obtain optimum electrical and mechanical performance of the crimped joint in service.

There are basically two other forms of infinitely variable crimp height devices, one requiring the horizontal movement of a sliding wedge, and the other by rotation of a disc with a SINGLE helical face. These both suffer from the same fault in that they only operate on the front pressure pad of the power press and in consequence impart an uneven and imbalanced thrust through the Applicator.

The present invention consists of TWO helical faces, each being 1800 of the radial surface of the mating discs, thus ensuring equal thrust from BOTH pads on the power press ram.

A specific embodiment of the invention will now be described by way of example, with reference to the accompanying drawings which consist of: Figure 1. shows the Mini-Applicator Ram Assembly in section and engaged with the press ram.

Figure 2. shows the threaded Ram Post.

Figure 3. shows the Setting Index Bar (with optional Index Pointer).

Figure 4. shows the helical faced Wire Disc (with flat top face).

Figure 5. shows the Fixed Helix, and an underside view to show the dimples for the ball engagement on figure 6. and the hole for the Anti-rotation pin.

Figure 6. shows the Insulation Disc with 8 different pad thicknesses.

Figure 7. shows the Applicator Ram on which this device is assembled.

Patent Application for Infinitely Variable Crimp Height Device.

Referring to Figure 1. the device is assembled in the sequence as depicted so that the Fixed Helix Figure 5. is mounted on the Applicator Ram (with or without a Spacing Washer as necessary), and it cannot be rotated when the Ram Post is tightened as the Antirotation pin locates in the Anti-rotation Pin Hole in the Applicator Ram Figure 7. The location of the Anti-rotation Pin determines the relative position of the other non-rotating parts Figures 3 and 5.

The Insulation Disc Figure 6 operates in the same manner as on existing Crimp Height Devices, using the 8 different thickness pad positions for selecting the required crimp height. The selected position is retained by the engagement of a spring loaded ball in the Insulation Disc Figure 6 into a dimple machined into the lower diameter of the Fixed Helix see Underside of Figure 5 drawing.

By rotating the Wire Disc Figure 4 the helical under surface of this Wire Disc will make contact with the helical upper surface of the Fixed Helix Figure 5 and the Wire Disc figure 4 will rise or fall in height according to the direction of rotation. This will increase or decrease the effective length of the Applicator Ram Figure 7 which will alter the finished Crimp Height of the crimped joint when the power press ram is at the Bottom Dead Centre of its stroke. When the Wire Disc Figure 4 has been rotated to give the required Crimp Height on the crimped joint, it is retained in this position by tightening a securing screw to engage the diameter above the Fixed Helix helical face Figure 5.

The thrust of the power press ram pads is transmitted through the flat top face of the Wire Disc Figure 4 through the helical faces of on the under side of the Wire Disc to the helical face on the upper side of the Fixed Helix Figure 5 and through the body of the Fixed Helix to the top of the Applicator Ram Figure 7, at the same time as imparting thrust through the flat under face of the Fixed Helix to the flat top face of the Insulation Disc Figure 6 and through the selected pad to the Insulation Crimper to form the Insulation Crimp.

The Wire Disc Figure 4 cannot exceed its maximum permitted height, or travel beyond the highest point of the helix as it comes into contact with the underside of the Setting Index Bar Figure 3 when it reaches its permitted maximum height. Alternatively a shouldered flange can be machined on the Ram Post Figure 2 to replace the Setting Index Bar and prevent the Wire Disc Figure 4 exceeding its maximum permitted height.

Claims (3)

1. Claims

   ti+i+i 1. An Infinitely Variable Crimp Height Device which can be used in place of a 4 fixed pad position crimp height disc to enable an optimum crimp height to be obtained between the Maximum and Minimum for the particular terminal wire range.
2. 2. The infinitely variable crimp height being achieved as claimed in Claim 1. by the rotation of a Wire Disc which has two identical half helix faces in contact with two identical half helix faces on a Fixed Helix Post, which is in a fixed position as determined by an Anti-Rotation Pin and locked in position by a Ram Post, the top of which engages in a Tee Slot in the underside of a power press ram that has two pressure pads located either side of the centreline of the ram.
3. 3. The Infinitely Variable Crimp Height Device achieves maximum balanced thrust from a power press as claimed in Claims 1 and 2 by virtue that the top face of the Wire Disc is always parallel to the faces of the two Pressure Pads under the power press ram. During the downward stroke of the crimp cycle of the press the Wire Disc, the Fixed Helix Post and the Insulation Disc (and Washer if fitted) form a solid mass of tightly engaged faces to achieve the thrust to create the crimp form to the desired Crimp Height.