GB2296176A - Heel top pieces - Google Patents

Abstract

A top piece for a shoe heel comprises an injection moulded single piece (1) moulding of soft thermoplastics material, comprising a ground engaging wear portion, and a plurality of pins (2) which project from the wear portion. Surrounding each pin is a sleeve (3) of hard plastics material, with a substantially cylindrical external shape. The sleeved pins fit into complementary holes in a shoe heel to secure the top piece to the heel. The sleeves are injection moulded and then pressed onto the pins. <IMAGE>

Description

TITLE: Heel Top Pieces DESCRIPTION Field of the Invention The invention relates to top pieces for use in the manufacture of footwear, particularly ladies footwear.

The top piece includes the wear portion of the heel that actually comes into contact with the ground. It is referred to as the top piece because the shoe is made upside down on a last, with the sole and heel pointing upwards.

Prior Art In a conventional (i.e. non-stiletto) heeled shoe, the top piece traditionally comprises a moulded piece of flat thermoplastics material, which is retained on the heel by adhesive, by staples or by a combination of adhesive and staples. The thermoplastics material is generally quite soft, to provide reasonable friction between the top piece and the ground when the shoe is being worn.

The staples which are used to affix the top piece to the shoe heel are simply U-shaped metal wires which are driven through the thermoplastics material of the top piece and into the material of the heel.

Recently, the use of staples on women's shoes has become increasingly unpopular. They are visible to the purchaser of the shoe and detract from its appearance. In addition, particularly with dance shoes, the staples can catch on tights or other clothing, and can cause damage to wooden dance floors. An alternative to the use of staples is to mould the top piece with projecting pins, which may be fitted into complementary recesses in a shoe heel to attach the top piece to the heel. However, the pins must be of a relatively hard plastics material in order that they may be pushed into the recesses without deforming, and in order that a firm anchorage is provided. Since the top piece is manufactured from a single moulding, the ground engaging portion must therefore also be hard, and does not provide good friction with the ground.

It is possible to mould the entire top piece from a soft thermoplastics material, but in this case the pins only act to locate the top piece correctly on the heel.

Because they are soft, they cannot be sufficiently tightfitting to bond the top piece to the heel.

Our published Patent Application GB 2276526 discloses a top piece which solves the above problems. It comprises an injection moulded ground engaging wear portion made of a soft thermoplastics material, moulded around two or more securing pins made of a relatively hard thermoplastics material. The pins are shaped such that in normal circumstances it is impossible to remove them from the wear portion without destruction of that wear portion.

Such top pieces have proved extremely successful.

However, they have one disadvantage, namely that they are time consuming and inefficient to manufacture.

The top pieces are manufactured as follows. The pins are injection moulded automatically and cut off the sprue ready for use. The ground engaging wear portion is also injection moulded, but must be moulded around the pins.

It is therefore necessary to place the pins in the machine before injection moulding of the wear portion can take place. The machine must be stopped while this is being done, and the moulding process is therefore slowed down dramatically. This procedure also limits the number of top pieces that can be moulded at a time, because the pins can only be left standing in the hot machine for a limited period. It has been found that a maximum of eight top pieces may be moulded at a time.

The aim of the present invention is to provide a top piece which overcomes all of the above difficulties.

The Invention The invention provides a top piece for a shoe heel, the top piece comprising: an injection moulding of soft thermoplastics material including a ground engaging wear portion and a plurality of pins projecting from the wear portion; wherein each pin is surrounded by a sleeve of substantially cylindrical external shape, made from a hard plastics material.

Such a top piece is preferably manufactured as follows: the injection moulding of soft thermoplastics material is made; the sleeves are also made by injection moulding, separately; and the sleeves are then pressed onto the soft plastics pins. Hence the injection moulding may take place non-stop without interference.

The moulding may be made of any soft thermoplastics material, preferably with a shore hardness of 46 shore D or less. Anti-slip polyurethane is a preferred material.

The sleeves may be made of any rigid plastics material, for instance high impact polystyrene or nylon. However, nylon has been found to be rather waxy and slippery, and therefore polystyrene is preferable.

The sleeves may be pressed onto the pins either automatically or by hand, but either way there is no disruption of the injection moulding processes. To make the pressing down of the sleeves easier, they may include an area of larger diameter towards their lower end., on which a tool may be located. These increased diameter areas may be accommodated in circular recesses in the wear portion of the moulding.

It is desirable that the sleeves are held firmly around the pins so that they do not become dislodged if, for instance, the top piece is prized away from a shoe heel.

Preferably the pins include an area of increased diameter at their upper ends (the ends furthest away from the ground engaging wear portion) over which the sleeves must be squeezed when they are first fitted. Additionally, or alternatively, the sleeves may include internal serrations which fit into complementary recesses in the pins and keep the sleeves in place. The sleeves may include slits extending from their upper ends to allow temporary expansion of the sleeves as they pass over larger diameter areas of the pins.

Drawings Figure 1 is a plan view of a top piece according to the invention; Figure 2 is a side view of a top piece according to the invention, showing pins fitted with two alternative types of sleeve; Figure 3 is a cross-section of a top piece according to the invention; Figure 4 15 a cross-section similar to that of Figure 3, but showing an alternative design of pin and sleeve; and Figure 5 is an illustration of the way in which a top piece according to the invention may be fitted in a shoe heel.

Detailed Description of the Drawings Referring to Figure 1, a top piece according to the invention includes an injection moulded single piece moulding comprising a ground engaging wear portion 1 and five pins 2. The moulding is made from a soft thermoplastics material. This top piece is suitable for a relatively large heeled shoe; a smaller top piece would include fewer pins.

Around each pin 2 is fitted a sleeve 3 of a hard plastics material. The hard plastics sleeve gives the pin sufficient rigidity that it may be inserted into a specially designed shoe heel as shown in Figure 5. The shoe heel is provided with recesses complementary to the pin/sleeve arrangement of the top piece, but of slightly smaller diameter. The sleeved pins are forced into these holes and a strong interference fit is formed. The sleeves are preferably made of high impact polystyrene which provides good frictional characteristics between the sleeves and the recesses.

As shown clearly in Figures 2 to 4, the pins 2 include a small bulge 4 around their upper end. This bulge ensures that, once fitted, the sleeve 3 will not dislodge from the pin 2.

The sleeves shown in Figure 3 include a serration 6 which on assembly pinches into the soft plastic of the pin 2 to form a a neck 7 in the pin 2. This keeps the sleeve securely in place on the pin. When a serration or similar device is used, the sleeve may include a slit 5, shown in Figure 2, which allows the sleeve to bend outwards to allow the serration to pass the bulge 4 on the pin.

Figure 4 shows smooth sleeves without serrations which are held in place by friction and by the bulge 4 on the pin only.

Each sleeve includes at its base a skirt 9 of enlarged diameter. This skirt may be engaged by a pressing tool when the sleeve is being pressed onto the pin. The moulding includes a circular furrow 8 around each pin for seating the base of the sleeve and accommodating the skirt, while ensuring that the upper surface of the top piece is flat where it contacts a shoe heel.

Claims (8)

CLAIMS:

1. A top piece for a shoe heel, the top piece comprising: an injection moulding of soft thermoplastics material including a ground engaging wear portion and a plurality of pins projecting from the wear portion; wherein each pin is surrounded by a sleeve of substantially cylindrical external shape, made from a hard plastics material.

2. A top piece according to claim 1 wherein at least one pin has an increased diameter at its upper end.

3. A top piece according to claim 1 or claim 2 wherein at least one sleeve has an internal projection, which fits into a complementary recess on a pin.

4. A top piece according to any preceding claim wherein at least one sleeve has at least one slit extending from its upper end towards its lower end.

5. A top piece according to any preceding claim wherein at least one sleeve has an area of increased diameter at its lower end.

6. A sleeve for a top piece according to any preceding claim.

7. A method for producing a top piece for a shoe heel, including the steps of: producing an injection moulding of soft thermoplastics material including a ground engaging wear portion and a plurality of pins; producing by injection moulding a plurality of sleeves of substantially cylindrical external shape made from a hard plastics material; and pressing the sleeves onto the pins.

8. A top piece substantially as described herein with reference to the drawings.