Hints for the improvement of trusses; intended to render their use less inconvenient, and to prevent the necessity of an understrap. With the description of a truss of easy construction and slight expence [sic], for the use of labouring poor / [James Parkinson].
- James Parkinson
- Date:
- 1802
Licence: Public Domain Mark
Credit: Hints for the improvement of trusses; intended to render their use less inconvenient, and to prevent the necessity of an understrap. With the description of a truss of easy construction and slight expence [sic], for the use of labouring poor / [James Parkinson]. Source: Wellcome Collection.
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![ON TRUSSES IN GENERAL. The great defect observable in Trusses, in genera], is their not applying themselves con- stantly to the part where the pressure is required. This defect obviously proceeds from the circum- stance of the point of their required bearing falling considerably out of the horizontal line, which the greater part of the instrument forms, when affixed to the body. In consequence of this, the strap w'hich is employed, in the simple Truss, to confine it in its situation, does really, by act- ing in an improper direction, tend so much to remove it from the situation in which it ought to be preserved, as to render it necessary to em- ploy an additional power, (the under-strap) act- ing in a contrary direction, for the purpose of counteracting and regulating it. What is here said will be more clearly under- stood by reference to fig. 5, of the annexed plate, where the dotted line at a marks the direction in which the strap b acts, and by which it tends to draw the pad into the position marked by the dotted lines at c, to counteract which tendency the under-strap d} is obliged to be em- ployed. Those](https://iiif.wellcomecollection.org/image/b22041631_0037.jp2/full/800%2C/0/default.jpg)
