초록 ▼

The invention provides a portable, collapsible sign stand assembly in which a sign is suspended from a support tube. The support tube is connected to a support base through a connecting member which includes a plurality of weakening members which cause the connecting member to fail upon impact. In o

The invention provides a portable, collapsible sign stand assembly in which a sign is suspended from a support tube. The support tube is connected to a support base through a connecting member which includes a plurality of weakening members which cause the connecting member to fail upon impact. In other embodiments, the support tube is weakened by weakening members so as to fail upon impact. In one embodiment, the weakened portions are placed under tension.

대표청구항 ▼

The invention provides a portable, collapsible sign stand assembly in which a sign is suspended from a support tube. The support tube is connected to a support base through a connecting member which includes a plurality of weakening members which cause the connecting member to fail upon impact. In o

The invention provides a portable, collapsible sign stand assembly in which a sign is suspended from a support tube. The support tube is connected to a support base through a connecting member which includes a plurality of weakening members which cause the connecting member to fail upon impact. In other embodiments, the support tube is weakened by weakening members so as to fail upon impact. In one embodiment, the weakened portions are placed under tension. he surface of the IDT for stabilizing the surface of the IDT includes the step of heat treating the device in an oxygen atmosphere to increasingly oxidize the surfaces of the IDTs that have been activated by etching in the frequency adjustment step. 13. A method according to claim 1, wherein the step of altering the surface of the IDT for stabilizing the surface of the IDT includes forming an altered layer on the surface of the IDT by oxidizing the IDT in air. 14. A method according to claim 1, wherein the step of trimming at least one of the piezoelectric substrate and the IDT to adjust an operation frequency of the surface acoustic wave device includes the step of reversed sputtering or ion gun processing. 15. A method according to claim 1, wherein the step of trimming at least one of the piezoelectric substrate and the IDT to adjust an operation frequency of the surface acoustic wave device includes the step trimming the surface of the piezoelectric substrate while trimming the IDT. 16. A method according to claim 15, wherein after the step of trimming, subjecting the device to a heat treatment in a nitrogen atmosphere to form an altered layer made of a stable nitrided film on the surface of the IDT to thereby stabilize the surface of the IDT. 17. A method according to claim 16, wherein a temperature of heat treatment is from about 85° C. to about 300° C. 18. A method according to claim 16, further comprising the step of changing a heating temperature or a heating time in the step of heating the IDT to nitride the surface of the IDT. 19. A method for producing a surface acoustic wave device, comprising the steps of: preparing a piezoelectric substrate; forming a thin film electrode on the piezoelectric substrate; etching the thin film electrode for forming an IDT; trimming each of the piezoelectric substrate and the IDT to adjust an operation frequency of the surface acoustic wave device; and exposing the surface of the IDT to an oxygen or nitrogen atmosphere for stabilizing the surface of the IDT. 20. A method according to claim 19, wherein the step of exposing the surface of the IDT to an oxygen or nitrogen atmosphere includes the step of heating the IDT in the oxygen or nitrogen atmosphere to oxidize or nitride the surface of the IDT.