Chenille type embroidery machines provide a "fuzzy" appearance of a pattern, for example, such as on an athletic award or "letter". The "fuzzy" appearance is formed by the use of a hooked needle which, in combination with a "looper" (which wraps thread around the needle), pulls a thread through a piece of material. Such a stitch is known as a "moss" stitch and is performed by the looper looping thread over the hook of the needle below the material to be embroidered. The needle then pulls the looped thread through and above the material. Another device known as the X/Y drive then pulls the material away from the raised needle causing the looped thread to slip off the hook. The needle again penetrates the material and the process is repeated, resulting in a "fuzzy" patterned item.
By reversing the hook of the needle so that the looped thread remains on the hook after the X/Y movement of the material, another stitch known as a "chain" stitch can be formed. The X/Y drive pulls the material and the thread as in the "moss" stitch procedure, but now the thread remains on the hook as the needle repenetrates the material and a linked "chain" stitch is formed.
Whichever stitch type is chosen, the X/Y drive of the chenille machine moves in a prescribed sequence of appropriate increments along a horizontal plane to allow the design to be embroidered onto the material. As the material moves in the horizontal plane, it is important to maintain the orientation of the hook of the needle to the X/Y frame movement. Thus, it is necessary to have a steering mechanism which allows the needle to turn to maintain the prescribed relationship to the X/Y frame movement to form a "moss" or a "chain" stitch.
It is also necessary to be able to adjust the needle to a specific height for the looped thread to be pulled through the material. The higher the needle, the higher or "fuzzier" is the appearance of the design or the longer is the link in the "chain" stitch which causes the "chain" to become "fatter" or "thinner" in appearance. It is also necessary to position the needle at a "home" position which is above the embroidered design in order to allow the material containing the design to be removed from the machine. Therefore, a mechanism is required to steer the needle rotationally as well as to position the needle vertically.
There are known chenille machines which perform these functions either automatically or manually. One embroidery machine, the Model ES-1114 TREASURE.RTM., by Nara Sewing Machine Industrial Co., Ltd., of Tokyo, Japan utilizes a manual operation. To steer the needle, a steering handle is provided which must be controlled by the operator. Additionally, the needle height is set manually by adjusting a needle holder. Thus, to sew a design of a desired height, the operator must manually set the height and manually steer the needle. Obviously, this requires skill and is at best a relatively slow process.
One known arrangement for automatic rotational steering and vertical height adjustment is used in chenille embroidery machines manufactured by Tajima Industries Ltd. of Japan. The Tajima machine comprises a first motor and a first driven shaft with a gearing arrangement for automatically steering the needle in accordance with a prescribed design. There is a second motor and a second driven shaft and gearing arrangement for positioning the needle vertically for proper height adjustment. The use of multiple shafts and multiple drive motors increases the complexity and cost of the chenille machine. Thus, there is a need for a method and apparatus to provide automatic steering and height adjustment from a single motor and drive shaft arrangement.