1. A piezoelectric vibration piece comprising:
a base made of a piezoelectric material;
a first and second vibration arms integrally formed with the base;
elongate grooves formed along longitudinal directions of the first and second vibration arms in principal surfaces of the first and second vibration arms;
inner electrodes disposed in the elongate grooves;
side electrodes disposed on side surfaces of the first and second vibration arms;
wherein widening portions being formed at a junction of the first and second vibration arms and the base;
wherein each of the widening portions includes an inner widening portion located adjacent to a crotch portion between the first vibration arm and the second vibration arm;
wherein a width of an at least one of the inner widening portions being widened toward the base while a widening degree is changed at a change point;
wherein the side electrode formed on a tip side of at least one of the first and second vibration arms from the at least one of the inner widening portions being not led to the principal surface located between at least one of the elongate groove and at least one of the side surface; and
wherein the side electrode formed on the at least one of the inner widening portions being led to the principal surface and the side surface of at least one of the first and second vibration arms at the inner widening portion and covers the change point.
2. A piezoelectric vibration piece according to claim 1,
wherein the at least one of the inner widening portions includes a plurality of straight lines that are connected to each other.
3. A piezoelectric vibration piece according to claim 1,
wherein a width of each elongate groove being constant along an entire length of each groove.
4. A piezoelectric vibration piece according to claim 1,
wherein a connecting electrode formed on the base; and
wherein the at least one of the side electrodes led to the principal surface and the side surface of at least one of the first and second vibration arms at the inner widening portion being connected to the at least one of the inner electrode of the second vibration arm through the connecting electrode.
5. A piezoelectric vibration piece according to claim 1,
wherein each of the widening portions includes an outer widening portion located outside between a first imaginary line along the longitudinal direction passing through a center of the first vibration arm in a width direction and a second imaginary line along the longitudinal direction passing through a center of the second vibration arm in the width direction; and
wherein at least part of the elongate grooves being formed between the inner widening portions and the outer widening portions.
6. A piezoelectric device which receives a piezoelectric vibration piece in a package or a case, the piezoelectric vibration piece comprising:
a base made of a piezoelectric material;
a first and second vibration arms integrally formed with the base;
elongate grooves formed along longitudinal directions of the first and second vibration arms in principal surfaces of the first and second vibration arms;
inner electrodes disposed in the elongate grooves;
side electrodes disposed on side surfaces of the first and second vibration arms;
wherein widening portions being formed at a junction of the first and second vibration arms and the base;
wherein each of the widening portions includes an inner widening portion located adjacent to a crotch portion between the first vibration arm and the second vibration arm;
wherein a width of an at least one of the inner widening portions being widened toward the base while a widening degree is changed at a change point;
wherein the side electrode formed on a tip side of at least one of the first and second vibration arms from the at least one of the inner widening portions being not led to the principal surface located between at least one of the elongate groove and at least one of the side surface; and
wherein the side electrode formed on the at least one of the inner widening portions being led to the principal surface and the side surface of at least one of the first and second vibration arms at the inner widening portion and covers the change point.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
We claim:
1. A pollution control device for reducing harmful emissions found in combustion gases, said device comprising:
a body having a first portion and a second portion releasably connected together to form a chamber therebetween,
an exhaust gas inlet on said body,
an exhaust gas outlet from said body,
at least one web member across said chamber, and
a plurality of catalytic converter elements held in said web member;
wherein said exhaust gases pass through said catalytic converter elements when passing through said chamber from said inlet to said outlet.
2. A pollution control device as claimed in claim 1 wherein said catalytic converter elements define an exhaust gas flow through area which is sufficient to prevent a significant pressure drop between said inlet and said outlet.
3. A pollution control device as claimed in claim 2 wherein said chamber includes at least two webs extending thereacross, each of said webs having a plurality of catalytic converter elements.
4. A pollution control device as claimed in claim 3 wherein said plurality of catalytic converter elements on each of said webs is the same.
5. A pollution control device as claimed in claim 3 wherein said plurality of catalytic converter elements on each of said webs is different.
6. A pollution control device as claimed in claim 1 wherein said catalytic converter elements are releasably held in said web.
7. A pollution control device as claimed in claim 1 wherein said catalytic converter elements are fixed in said web.
8. A pollution control device as claimed in claim 1 wherein said chamber includes a flow control means to improve a flow of said exhaust gases through said chamber.
9. A pollution control device as claimed in claim 8 wherein said flow control means comprises a baffle.
10. A pollution control device as claimed in claim 9 wherein said flow control baffle is a conical baffle extending from said inlet.
11. A pollution control device as claimed in claim 1 further including at least one gas injection port in said chamber.
12. A pollution control device as claimed in claim 11 further including a blower associated with said at least one gas injection port.
13. A pollution control device as claimed in claim 11 wherein said at least one gas injection port is adjacent to said web, said injected gas facilitating a reaction causing a reduction of pollution.
14. A method of servicing a pollution control device comprising:
a) supporting said device in place;
b) separating a first portion from a second portion;
c) removing and replacing a web and associated catalytic conversion elements; and
d) releasably attaching said first and second portions together again.
15. A pollution control device for reducing harmful emissions found in combustion gases said device comprising:
a body having an inlet and an outlet and a chamber formed between;
a web forming a barrier across the chamber between the inlet and the outlet, and having a plurality of openings formed therein; and
a plurality of catalytic converter elements held in said openings in said web member;
wherein said exhaust gases are forced by said web to pass through said catalytic converter elements.