Master's Thesis

Design of sports bow

Author of thesis: Ing. Jan Bílek

Acad. year: 2006/2007

Supervisor: doc. akad. soch. Ladislav Křenek, ArtD.

Reviewer: The opponent will be displayed after his opinion is published.

Abstract:

My aim in this graduation theses is to adjust the existing equipment of archery for the blind, and to design a new one.

The equipment used nowadays consists of a support and auxiliary listels. The very integral part is an assistant of the blind archer who first positions everything and prepares for shooting. The blind archer fixes his or her stance by means of all the mentioned aids and shoots.


In the Czech Republic, a new concept of the sight  for archery of the blind has been developed by Mr. Jiří Mojžíšek. This technique make the archery avaiable for greater number of the blind achers because it does not claim an assistant‘ s help at the very shooting and eliminates all the sizable additional arrangement.

The sight is fixed directly at the fingers of the bow hand. The sight placed on the bow allows the blind archer free movement at the shooting mark. The archer can shoot from other position. Now the shooting is very similar to the shooting of the non-blind.

The principle of sighting is based on the equipment which detects a relative position between the bow and the target. Position change is transferred through the nylon cord in the sight to a stake in the middle of which the cord passes through. The detection stake has at its end a dot which together with the two dots at the sight creates an equilateral triangle in the case that the sighting has been performed correctly. Now the blind archer by contact of his or her fingers checks the relative position of the dots.

Design of a new ergonomics of the existing grab handle was necessary because at the position evaluation of the double-reversing arm, a gap occurred at the original grab handle of the bow hand. Therefore the whole part of palm of the archer´s hand was not used and the shooting demanded more strength and was less comfortable. Both aspects could influence shooting accuracy. 


Technically the most difficult part of these theses was to design a new functional solution for vibration absorbtion of the bow after a bow-shot. The stabilization equipment is fixed directly on the bow in the part which is under the bow hand.

The blind archer is not able to control the stabilization equipment in a precise way and therefore attacs the nearby standing people. When the bow is housed in the stand, the archer himself tumbles over the side arms of the stabilization equipment.

I was bethinking the impact spreading and itended to design shape and layout of the stabilization equipmentin the way to eliminate the impacts.
In order to confirm these hypothesis, I have performed measurement of vibration of a bow when shooting. From these records, I could set a spreading way on the bow and identify the spot with the highest amplitude where a stabilizer is to be placed. In order to preserve the original bow shape ( the C-shape), I have decided to place absorbation equipments on a support that copies the bow armes and is fixed in th same way as bow armes in the body of the bow.


When seeking after a shape concept, I came out of shapes being used nowadays and intended to come to such a new complex that could engage the sight, absorbation supports and adjusting device.
In the designed version, there are a few domination curves that make the shape a compact complex. Partial curves go out of single principle curves. These partial curves come into curves of the facilities - the sight, adjsting device and bow arms.

Keywords:


design,design bow,archery,archery blind, Jan Bílek,blind,sight blind,new conception damping, damping archery,Jiří Mojžíšek,archer federation,shooting blind,to blind,aim,

Date of defence

12.6.2007

Result of the defence

Defended (thesis was successfully defended)

znakmkaBznamka

Grade

B

Language of thesis

Czech

Faculty

Department

Study programme

Mechanical Engineering (M2301-5)

Study branch

Industrial Design

Composition of Committee

Karel Kobosil (předseda)
doc. Ing. Ivan Mazůrek, CSc. (místopředseda)
Ing. Milan Kabát (člen)
akad. soch. Petr Svítil (člen)
PhDr. Jana Pavlíčková (člen)
doc. Ing. arch. Jan Rajlich (člen)
prof. RNDr. Miroslav Doupovec, CSc., dr. h. c. (člen)
prof. PhDr. Jan Sedlák, CSc. (člen)
akad. soch. Zdeněk Zdařil (člen)
doc. akad. soch. Peter Lehocký, ArtD (člen)

Reviewer’s report
akad. soch. Tamara Buganská